MULTIPLY-EXCITED MAGNETIC FIELD SYSTEMS

Singly excited devices are generally employed for motion through a limited distance or rotation through a prescribed angle. Electro-mechanical transducers have the special requirement of producing an electrical signal proportional to forces or velocities or producing force proportional to electrical signal (current or voltage). Such transducers require two excitations one excitation establishes a magnetic field of specified strength while the other excitation produces the desired signal (electrical or mechanical). Also continuous energy conversion devices motors and generators require multiple excitation.

Figure- 6  shows a magnetic field system with two electrical excitations one on stator and the other on rotor. The system can be described in either of the two sets of three independent variables (1, 2, θ) or ( i1, i2, θ). In terms of the first set





Electromagnetic Force, f

    For the current-carrying conductor, the force (known as Lorentz force) produced on the conductor can be determined from the following equation:

                                           f = Bli

where B, l, and i are mutually perpendicular. The direction of the force can be determined by using the Fleming’s Left Hand Rule.


Fleming’s Left Hand Rule:

 “Hold out your left hand with forefinger, second finger and thumb at right angles to one another. If the forefinger represents the direction of the field, and the second finger that of the current, then thumb gives the direction of the motion or force.”


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LPT PORT EXTENDER

LPT PORT EXTENDER

Because of the standard LPT printer parallel port can only send data and can not receive data, so I decided to make this LPT port extender card to improve the capability of that matter. Standard LPT have 8-bit DP (Data Port), 5-bit PS (Status Port) and 4-bit PC (Control Port). This bits divided by 8+4 bits of output bits and 5 bits of input bits. To get the 8-bit input and output port, we used a nibble of this real input and output port to simulate of a byte of input and output port (bi-directional port) by the control bits of course we used 2 bits of the DP port.
Here are the implementation :
  • Nibble Output = 4-bit PC (PC-0 ~ PC-3, Note that PC-0, PC-1, PC3 are inverted output. First & second nibble are controlled by the software).
  • Nibble Input = 4-bit PS (PS-4 ~ PS-7, Note that PS-7 is inverted input. First & second nibble are also controlled by the software too).
  • Control bits = 2 bits of DP (DP-6 ~ controlled for lo-nibble & hi-nibble, DP-7 ~ controlled data direction). 

    click the image for zooming

    Fig.1. LPT port extender schematic diagram.
     
     

     Parts List : 
      Hex Inverter (74LS04) ............................1 pcs
Quad NAND gates (74LS00) ......................... 1 pcs
Quad Latch (74LS173) ............................. 2 pcs
Octal 3-State buffer (74LS244) ................... 1 pcs
      100 nF ........................................... 5 pcs
      DB-25 Socket male/female .........................1 pair
Cable (0.25 sq x 19c) ............................3 m



    Figure 1. shows the schematic diagram for this LPT extender. The condition of the logic state are show in this tabel :



    Direction
    Lo/Hi-Nibble 
    Data (Q) 
    74LS173 
    74LS244 
    Description 

    (DP-7) 
    (DP-6) 
    Lo/Hi-Nibble 
    Lo-Nibble 
    Hi-Nibble 
    Lo-Nibble 
    Hi-Nibble 
    0  0  0/1  0/1  Q'  Hi-Z  Hi-Z  Lo-Nibble Data Out 
    0  1  0/1 Q'  0/1  Hi-Z  Hi-Z  Hi-Nibble Data Out 
    1  0  0/1  Hi-Z  Hi-Z  0/1  Hi-Z  Lo-Nibble Data In 
    1  1  0/1  Hi-Z  Hi-Z  Hi-Z  0/1  Hi-Nibble Data In  
    Tabel.1. Logic state of the LPT port extender.
     
     
    One of the PCB design layout shown in fig.2. This use single side PCB, so it has a lot of jumper wire. You can make another design if you want, but this one is work well (my prototype).
    Fig.2. LPT port extender PCB layout.
    Here is the software example written in Pascal language style :
        
    TYPE
    LPT_Port     = (LPT_1, LPT_2, LPT_3, No_LPT);

CONST
     DP          : ARRAY[LPT_Port] OF WORD = ($3BC, $278, $378, $3BC);    { Data Port }
     PS          : ARRAY[LPT_Port] OF WORD = ($3BD, $279, $379, $3BD);    { Status Port }
     PC          : ARRAY[LPT_Port] OF WORD = ($3BE, $27A, $37A, $3BE);    { Control Port }

VAR
   Port_DP            : WORD;
   Port_PC            : WORD;
   Port_PS            : WORD;
   LPT                : LPT_Port;

PROCEDURE Out_Port(Data : BYTE);
VAR
   Temp : BYTE;

BEGIN
     Temp := PORT[Port_DP];
     PORT[Port_PC] := (Data AND $0F);
     PORT[Port_DP] := (Temp AND $3F);
     PORT[Port_PC] := ((Data SHR 4) AND $0F);
     PORT[Port_DP] := ((Temp AND $3F) OR $40);
END;

FUNCTION In_Port : BYTE;
VAR
   Temp : BYTE;
   Data : BYTE;

BEGIN
     Data := 0;
     Temp := PORT[Port_DP];
     Temp := Temp AND $3F;
     PORT[Port_DP] := (Temp OR $80);
     Data := ((PORT[Port_PS] AND $F0) SHR 4);
     PORT[Port_DP] := (Temp OR $C0);
     Data := (Data OR (PORT[Port_PS] AND $F0));
     In_Port := Data;
END;
    To access the port just simple, use the statement Data_Read := In_Port; to read in the data and Out_Port(Data_Write); to write out the data, and so on ... and so on ....
    PCB Mounting. It is very simple to put the whole unit on a piece of board like showing in the figure.3. But all of this depends of your design idea. I prefer to place all of it on the board and not in the box, because it will be more easy to make some test to the circuit or to make some measuring voltages or logics. 
    Fig.3. LPT port extender PCB mounting.
    Fig.4. LPT port extender prototype card.
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Motorola Xoom set for preorders at Best Buy

Best Buy is taking preorders for Motorola's Xoom, a tablet that is expected to challenge Apple's dominance of the market. 



         Motorola's Xoom is priced at $799 with 3G, upgradable to 4G.
         (Credit: Motorola)
 
A new entry on Best Buy's site shows the Xoom priced at $799 for a version that is 3G-capable and upgradeable to 4G.

The 10.1-inch tablet is expected to give the iPad a run for its money, just as Motorola's Droid phones have done in the smartphone space. The Xoom will pack a dual-core Nvidia processor, a 1,280x800 resolution display, and dual cameras. Available in stores Thursday, the tablet has a 32GB flash drive and 1GB of system memory.

The iPad 3G--priced at $729 for a 32GB model--by comparison, has a single-core Apple A4 chip, no cameras, and a 1,024x768 display. The iPad is also not upgradeable to 4G. Of course, all of this could change when the iPad 2 makes an expected appearance. The second-generation iPad is expected to have a dual-core processor, improved graphics silicon, and dual cameras, among other new specs.
One of the most anticipated features of the Xoom is Google's Android 3.0 (Honeycomb) operating system that has specifically been designed for tablets and taps into Nvidia's dual-core Tegra processor to deliver "PC-like performance" and multitasking.

Best Buy also lists a number of accessories for the Xoom such as a dock, a Xoom case, speakers, and a wireless keyboard--all from Motorola.

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SAMSUNG TAKES DRAM 512-pins wide

LONDON – Samsung Electronics Co. Ltd. has announced the development of a 1-Gbit DRAM with a 512-pin wide I/O interface intended for mobile applications such as smartphones and tablet computers.

The chip is implemented in a manufacturing process technology somewhere between 50- and 59-nm and Samsung is also due to present a paper related to wide I/O DRAM technology at the 2011 International Solid-State Circuits Conference being held from February 20 to 24 in San Francisco.

To boost data transmission, the wide-I/O DRAM uses 512 pins for data input and output compared to the previous generation of mobile DRAMs, which used a maximum of 32 pins. Including pins for commands and power supply and its regulation the WIO DRAM is designed to have ip to 1,200 pins.

Samsung did not indicate whether it intends to offer the 1-Gbit WIO DRAM as a packaged part or to use it as a bare die in multi-chip packages. Nor did Samsung state when engineering samples of the 1-Gbit WIO DRAM would be available or it would be in volume production.

Nonetheless, as a result of the extreme I/O the 1-Gbit WIO DRAM can transmit data at 12.8-Gbytes per second, increasing the bandwidth of mobile DDR DRAM eightfold, while reducing power consumption by approximately 87 percent. The bandwidth is also four times that of LPDDR2 DRAM, which is approximately 3.2-Gigabytes per second, Samsung said.

To follow on from the WIO DRAM launch Samsung is planning for a 20-nm class 4-Gbit WIO mobile DRAM to become available in 2013,

"Following the development of 4-Gbit LPDDR2 DRAM last year, our new mobile DRAM solution with a wide I/O interface represents a significant contribution to the advancement of high-performance mobile products," said Byungse So, senior vice president, memory product planning and application engineering at Samsung Electronics, in a statement.


Samsung extends lead in DRAMs

DRAM revenue for the South Korean company in the fourth quarter of 2010 amounted to $3.6 billion, equivalent to 41.7 percent share of an $8.7 billion market, according to the firm. Samsung’s share rose 1 percentage point compared to the third quarter, according to the report.

Samsung’s performance was in direct contrast to a declining DRAM market, in which average selling prices (ASP) tumbled more than 28 percent in the final quarter of 2010, IHS iSuppli research shows.

“Samsung succeeded in picking up more business thanks to an astute playbook marked by a diverse product portfolio that hedged against excessive ASP declines, as well as an aggressive budget for capital expenditure that made sure the company’s shipments kept pace with the competition,” said Mike Howard, principal analyst for DRAM and memory at IHS, in a statement.

No. 2 Hynix Semiconductor Inc. of South Korea has held approximately 22.0 percent market share for eight consecutive quarters. And third-ranked Elpida Memory Inc. of Japan, which suffered the biggest drop in revenue in the fourth quarter, down 35 percent to $1.1 billion and 13.0 percent share.

Micron finally began to see significant shipments being counted from its purchase of a stake in Taiwan’s Inotera Memories a few years ago. Micron’s market share edged up to 12.5 percent in the fourth quarter, up from 10.5 percent in the third quarter.

Still, it's a mixed picture for DRAMs. ''Memory orders remain skittish, mainly due to the uncertainty in the DRAM market,'' according to a report from VLSI Research.

''The positive is that Intel’s (chip) recall has had very little impact on the PC market,'' according to the report. ''Top notebook manufacturers are reporting stable market conditions and expect shipments to decline only 2 percent in Q1. While this is better than the typical seasonal drop of Q1, it’s coming off a low base in Q4. Although table proliferation remains a concern, notebook manufacturers expect to see further improvement in Q2.  Shipments are projected to increase 15-20 percent sequentially, almost 5 percentage points higher than the average growth of Q2.''

Prices are up. ''The overall spot price-per-bit for DRAM rose for the third straight week, this time by 1.4 percent. The increase was driven primarily by non-branded DDR3 in what was a fairly quiet week,'' according to the report. On the other hand, ''NAND flash extended its streak to the thirteenth consecutive week as the overall spot price-per-bit rose by another 2.6 percent.''

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Inside Samsung's 30-nm-class, 'green' DDR3 SDRAM


When Samsung Electronics Co. Ltd. announced it would be the first to market with "30-nm-class" DDR3, the analysts at UBM TechInsights anxiously awaited a closer look at what was inside.Claiming to be the industry's first 30-nm-class SDRAM device, the Samsung K4B2G0846D has encouraged a healthy debate within our walls now that we have it on hand.
Primarily, most of the discussions have been on why and how the South Korean manufacturer can refer to their latest SDRAM offering with the term "30-nm-class."



Samsung K4B2G0846D 2Gbit DDR3 SDRAM


There are, of course, a number of different ways of measuring 'node' for SDRAM, so it's important to look at the big picture, and not focus too much on a specific measurement.

With that in mind, how does Samsung's newest stack up? To better understand the breadth of Samsung's newest SDRAM, here is a quick comparison of their DDR3 device to the recently analyzed DDR3 SDRAM devices from the other manufacturers at the previous process node:

Table 1: Comparison of DDR3 devices from different companies at different nodes

From the table, there are interesting findings that come to light when you take a look at the differences between the half-pitch metrics for each offering, and how that compares to the unit cell area. It is very interesting to note that where Samsung's Shallow Trench Isolation (STI) half-pitch is substantially smaller than its wordline half-pitch, the reverse is true for Micron Technology Inc.
Ultimately, manufacturers are looking for a reduction in cell area—and Samsung has now established a clear lead. So how did they do it? Looking at the above table, you can see that most of Samsung's shrink is in one dimension. Squeezing the STI by that much was quite the engineering feat.

To temper our enthusiasm, however, it must be noted though that it is a shrink in one dimension and the cell architecture has not changed; therefore it is still considered 6F2. This modified version of 6F2 architecture, however, still presents a reduction in cell area size of 38 percent on Samsung's 48-nm DRAM and a reduction in cell area size of 24 percent in comparison to Micron's 42-nm memory device.

Beyond the 'node'
 

Though our wordline half-pitch measurement indicates a process node of 46-nm, if we were to look at the half-pitch of the STI (a much tighter arrangement in this DRAM structure compared to previous generations), we could conceivably call this a 30-nm device. However, under traditional 6F2 architecture, if F was to equal 30-nm, the cell size should be 0.0054 um2 (the calculation comes from 2Fx 3F= (0.030um * 2) x (0.030 * 3)=0.0054um2), smaller than the cell size we have measured of 0.0085 um2.

For our measurement to match this area, the 'F' would indicate a process node between 37- and 38-nm. And therein lays the debate on how to classify this Samsung offering and why Samsung probably chose the naming convention of 30-nm-class. Regardless of how we want to define the 'node', we can all agree that this is a milestone in DRAM process technology for Samsung.

Cross-sectional image of Samsung 30-nm-class DRAM

From a technology perspective, we're of course interested in far more than just cell size. Samsung has a history of introducing process changes well in advance of them being necessary. Kind of a test run to work out the inevitable kinks without the complications of trying to do everything at once. Has Samsung once again looked into the crystal ball, and worked to make the next generation that much easier to produce?

As the DRAM industry responds to this latest innovation, we'll be able to answer that question with more confidence.
We've also seen from Samsung's literature that there is a substantial improvement in low power characteristics. That may point to other process changes with this new generation beyond just the shrink. Some of these changes may prove to be just as interesting as the shrink itself, given the consumer implications in such a cut-throat market segment driven by cost and razor thin margins.

With this new device, the world's largest memory manufacturer aims to offer significant power savings to their customers while simultaneously lowering their own internal production costs. It remains to be seen, however, if this process shrink will translate to those goals.

DRAM decline to last to 2013, says iSuppli

LONDON – Good news for OEMs and consumers, bad news for DRAM makers, the global DRAM revenue decline is set to last until 2013 despite increasing numbers of bits shipped, according to market research firm iSuppli Corp.

Worldwide DRAM revenue in 2011 is forecast to decline to $35.5 billion, down 11.8 percent from $40.3 billion in 2010. The double-digit drop contrasts with the 77.5 percent increase in DRAM revenue in 2010 compared to 2009. And the decline is expected to continue in 2012 to fall to about $25 billion in 2013.

The market for DRAM, the main memory format for games consoles and desktop and notebook personal computers, turned in 3Q10 as average selling prices (ASPs) plunged downwards, ending five consecutive quarters of increases.
 



ASPs will drop in 2011, by 44.7 percent to $1.44, down from $2.61, according to iSuppli although the firm did not mention to what component the quoted figures referred.
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E PROMER part-2

6. Testing



When everything was done for the first time, the circuit must be test for the correct working. Run the test program with a good multitester. The test program look like this : 

click the below images  for zooming


The test point can be tap at EPROM socket or PIE socket. Note that pin 14 EPROM socket is common ground. 

7. Mounting

        For the compact mounting, all the components and pcbs can be put in one box, except for the transformer. My prototype has dimension about 20 cm x 15 cm x 5 cm and made by plywood and seems nice.

8. Next Modifications & Expansions

  
Below are all the modifications and some expansions which can be added to the circuit. Note that in my prototype, this modifications & expansions didn't implemented.
  • Adding Vcc voltage for intelligent programming, since intelligent programming needs +6V for power supply voltage during programming and verifying process (this option implemented in software). Note: jumper wire in the top of PIE must be removed and +Vcc connected to the circuit below.
  • Adding hardware delay timer (one shot pulse delay timer). This must be applied for 2 purpose ie. for standard programming (50 ms delay pulse) and for intelligent programming (1 ms delay pulse). But this option has dilemma, using a good hardware timer (hi precision) cause a high cost too, on the other hand, using a usual timer can save cost but sacrifice the delay precision time. So I think this expansion only for studying purpose, how to make a good and effective routine for hardware interrupt. A good alternative is to use the PC PIT itself. Note that reed switch relay (DIL, operate at 3.7V ~ 10V) may be hard to find. It can be substitute by a general relay, but the +5V voltage also hard to find too, so it must be change to the proper supply (+12V relay usually general). Another alternative is to build a self made reed switch relay from a reed switch and a bunch of winding coils. The rule depends to the contact sensitivity, eg. sensitivity = 50 A/turns, so the relay needs 50 mA at 1000 turns or 100 mA at 500 turns, etc. (this option didn't implemented in software, may be next time). If the relay is too sensitive, add 4k7 resistor compensate between input and basis darlington transistor.

    8. My Prototype

    -->

            Here is the implementation of the layout panel above. The dimension about 20 cm (L) X 15 cm (W) X 5 cm (H). All the component include heatsink plate for IC, except for the trasformator can be filled inside

    9. Feedback

            A few reader gave me feedbacks, that some already built it but had found some difficulty. Another with apreciate. But all of it I think that more important things is a help to understand Indonesian. So for that I already prepare the help file in hope that it will be useful for another person who doesn't know Indonesian. The translate is in English. May be helpful.


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    6-digits 7-segment LEDs Display Driver Circuit

    A. 6-digits 7-segment LEDs Display Driver  

    This device also used a very common components. For the driver I used TTL seven segment decoder/driver 74LS247 (Family of 7447 is ok!). It needs one IC for every digit LED, The LED used is a common anode type. The color is up to you. Every segment needs a pull up resistor. Used a 220 Ohm for a bright light and a bigger one (about 470 Ohm) for a dimmer light. I used a 220 Ohm resistor and a green color LED. Up to six digits can hold by DB-25 connector, because the input of 74LS247 is a BCD (4-bits). For the dots we used a DB-9 connector, through the buffer 7407 IC for pull up the power, so the input of DB-9 connector could be tired to any TTL level logic. One pin of DB-9 also used for lamp test (LT) function. Use a female type connector, because you can use the standard parallel connector selling in the market without making it anymore. Ok, nothing more to say, lets go to the project.

    B. Schematic Diagram  

    Here is the complete schematic diagram (I drawn it with Protel V1.0).

    click the image for zooming 



    C. PCB Layout

    For the PCB layout, I drawn it using a single layer side. Here is the complete PCB layout (I drawn it with Protel V1.5).
     

    click the image for zooming 



    D. Mounting

    All the circuit are very best if it can fit in a box. I put it all in a box size of 20 cm (long) X 10 cm (wide) x 3 cm (tall). The layout panel consist of 6-digits 7-segment LEDs, miniature jack socket, miniature on/off switch, power indicator lamp, DB-9 female connector for dot bits LEDs, and DB-25 female connector for 6-digits BCD input LEDs. Its quiet a compact device 


    E. Components
     
    Notes: Resistor R1...R36 refer to the ICs used. see text for any detail info.
    • Resistors:
        1. R1...R48=220 Ohm.............48 pcs
    • Diodes:
        1. SS1...SS6=7-Segment LED, common anode, green color..6 pcs
    • ICs:
        1. Decoder/Driver IC1...IC6=74LS247...........6 pcs
2. Buffer IC7=7407........................... 1 pcs
    • Others:
        1. Con1=DB-25 female socket........................ 1 pcs
2. Con2=DB-9 female socket......................... 1 pcs
3. Con3=Miniature jack socket (mono) - Optional.... 1 pcs
4. S1=Miniature on/off switch (spdt) - Optional.... 1 pcs
5. Indicator lamp 5V - Optional.....................1 pcs

    F. Testing



    The software test needs LPT expander card for interfacing the circuit. It can both except LPT expander card when run on LPT port or using decoder for PPI-8255. There are 3 kind of test; first is displaying any numerical inputed by user, second is counting up from 0 to 999999, third is displaying the clock. Please try by your self.



    G. Prototype

    My prototype shown below. The panel made by plastic sheet same as the 36-LEDs display driver. Here is the picture.





    H. Application


    Here is the application program and hardware. The program test on 80486-DX2-66 PC/AT computer



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    PROGRAMMABLE LOGIC CONTROLLER (PLC)







    What is a Programmable Logic Controller (PLC)?



    click the image for zooming

      



      Many-many years before PLC was infented, machine controllers using a combinational circuits, like combine of many relays, timers or any other devices, mechanical controller like cams shaft and drums, include of electronics circuits to made a sequence process (logic control system). With this old sequensial controller, the circuit looks very crowded and usually it is hard to find the malfunction part, or even to modify the sequence, besides that it needs more time and cost too. The old sequensial controller also implemented only in small scale or medium scale system and specific to a system or machine, because in large scale system, it is hard to test the ability and the efficiency of the entire system. This system also cannot implemented in the process that needs a high speed control. So thats why the PLC was infented. Many new industries now a day already implemented PLC systems to control their machines.

            PLC is operated by the instruction input from the input devices (like push button switch, selector switch, digital switch, etc. provided on the operation panel, or sensors input from the limit switch, proximity switch, etc.) used to detect the operation condition of the equiptment, and serve to control the driving loads, output devices (such as solenoid valve, motor, electromagnetic clutch, etc. and indication loads such as pilot lamp, digital indicator, etc.). The transmission of output signal against these input signals is determined by the contents of program to be provided to the PLC. The light loads such as small type solenoid valve, pilot valve, pilot lamp, etc. can be directly driven by the PLC, however, the heavy loads such as 3-phase motor, large capacity solenoid valve, etc. need to be driven through the contactor or the intermediate relay. Such contactor, intermediate relay, power breaker, etc. are installed in the control panel together with the PLC. The PLC will play the important roles as a small type, high-reliability and flexible brain when designing the automated product machining, assembling, transfer, inspection, packing, etc.
    -->


            The PLC is composed of electronic circuits with a micro-computer (micro-controller) centered, however, it can be equivalently regarded as an integrated body of ordinary relay, timer, counter, etc. The input relay built in the PLC is driven by the external switch through the input terminal. The output relay built in the PLC is provided with various internal contacts in addition to the external output contact. Besides, it is incorporated with various types of elements such as timer, counter, auxiliary relay, state, coil and function block, etc. In addition, these elements are provided with many electrically normaly-open contacts and normally-close contacts, and can be used optionally with in the PLC.
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    Analog To Digital Converter (ADC, A/D, A–D, or A-to-D)

    Simple ADC-0808 circuit using bi-directional LPT parallel port
    --> A. PREFACE
     In real world life, there is nothing state like digital state, 'one' state is 'true' while 'zero' state is 'false', or another phrase similar like that, 'one' state is 'there is power, voltage, or some thing else' while 'zero' state 'is there is no power, voltage or some thing else'. In another word like 'black' or 'white' state. Life is more easy, if the condition is like that, just the combine of logic state. Since we know, logic state is better to understand. But a pity, usually many things in the world are not like that. Some are in analog state. Many conditions are not in state 'one' or not in state 'zero', but in the 'grey' state. What is mean 'grey' state??? Say it like this, eg; we want to represent the condition of room temperature. Room temperature going from 15o Celsius to 30o Celsius. If we represent it with the 'one' - 'zero' condition, how to represent the condition??? which one is the 'one' state? or 'zero' state? Because the range are in the 'grey' state!!! Another example; in our house, there is a valve to open or close a flow. These open or close condition could be represent by the 'one' state or 'zero state. But, how if we just want to open it a little, a half, or only needs a small flow, that is the 'grey' state. How much the opening valve condition and to be represent like what???
            Fortunetely, some scientists have found the technique or the device to represent such a condition. It called Analog to Digital Conversion (ADC). By using this, analog state could be represent and accepted to be compute. The 'grey' state could be represent as a number between the range interval depends on the real world condition state. Not just the 2 choice only. The number of condition state quantity depends on the resolution of the ADC, and represent by : 2n bit. The higher is the resolution, the more precise is the state condition to be represent. And in vice versa, the condition represent by the number of range interval could be applied to the real world state using Digital to Analog Conversion (DAC). So the real life more easily then .....
            This time we learn about Analog to Digital Converter (ADC) and Digital to Analog Converter (DAC). There are many types of the chips, so I will put such things as I learn it by time to time, and just only the chips with I ever deal with. Let's go to rumble!!!

    B. ANALOG TO DIGITAL CONVERTER (ADC)

            ADC used to capture the analog signal state and represent it as a digital state in a limited time interval. Every ADC chip has a resolution and an interval time to convert the state. The higher resolution and the smaller converting time make the chip more expensive. Besides that there are some technique used in the chip to convert the state. But I don't want to deal with the technique. I just want the higher resolution, easy to used and the important things that, it's cheaper!!! What's a hobby!!!
     

    1. ADC-0808/ADC-0809

            ADC0808/09 chip has 8-bit resolution (256 state condition), easy to used, and cheaper. This is the popular one. The conversion time about 100 usec. It has 8 channels analog input (IN-0 ~ IN-7). The proper channel activated by selecting address lines (ADD-A ~ ADD-C). Clock frequency about 500kHz. The type 0808 and 0809 almost the same. The conversion begin when the input START and ALE be made low, then by polling output EOC, or tired to INT in microcomputer/microcontroller, and wait till it becomes high, the data ready to read. No need to adjust zero offset and full scale adjustment. Just tired to +Vcc and Ground.


    CLICK THE BELOW IMAGES FOR ZOOMING


    1.a. OLD DESIGN LPT ADC

            First deal with this type ADC, inspired by : Rolan Yang. I got his design from electronic CD contain a bunch of many designs from internet. He made a simple LPT scope using interpreter BASIC, just only a few lines long. Very good example indeed. I attached the original version here for history. By follow his design, I arranged the pcb layout like this : 

    I tried to improved the original software, but the speed is very slow. I think it's about a few kHz. But for the curiosity, it's quiet interesting!!! Here are the software also in interpreter BASIC, or compiled version using DOS Quick Basic. The software also could be obtain in Pascal version.

    1.b. ADC-0808 CARD

            This time I make the universal ADC card using the same type ADC-0808. There are many ADC cards selling out there, if you don't want to bother build it by your self, you can buy one. But I prefer to build it by my self, to increase my knowledge of everything. First of all, because many of my design recently using microcontroller, so the card must be support to use by both system, using it with personal computer or using it with microcontroller projects. The schematic is like this :
    ADC card using ADC-0808_0809 schematic diagram (adc_0808_card.sch, adc_0808_card_S.pdf)
            PCB layout is a little complex because I must make the board to accommodate my purpose. This design based on one of the popular design sell on the market, and compare to the reference that I could get. Many jumper to make the selection more variety. So at last, the result is like this :
    -->
    ADC card using ADC-0808_0809 PCB layout (adc_0808_card.pcb, adc_0808_card_layout.pdf, adc_0808_card_artwork.pdf)


    2. ADC-0820

            Second type chip, when I make the LPT oscilloscope from www.volny.cz/elecon/elecon.html based on Bojan Banko design. A pity the links already dead, but elecon volny still there. This ADC-0820 chip is 8-bit resolution also, but it's a high speed. The conversion time only took about 1.5 usec. No need for external clock, and easy to used. It's a flash type ADC.

    2.a. LPT OSCILLOSCOPE

            I made the circuit exactly like elecon own, and used the software too. Besides that, I made also the experiment with pascal software. Maybe in Delphi for the next experiment.


    The link to Bojan Banko LPT oscilloscope at Geocities site, already dead, but elecon volny LPT oscilloscope design is still there.

    My own LPT oscilloscope base on both design could be seen here.

    3. ADC-0804

            ADC-0804 has 8-bit resolution. The conversion time takes about 100 usec. Already has internal clock generator. No zero adjustment is required, and the reference voltage can be set internally or external. This chip also easy to use and cheaper. It has only one channel analog input. Can be made for differential input channel. The span can be adjusted also.


    3.a. ADC-0804 CARD

            By the time when I made the first card, I also made this card to be implemented on temperature controller project. The card be made universal, so I could use the design later on for the next project. As usual the design must accommodate both for use with personal computer or using it with microcontroller projects. The schematic is like this :
    ADC card using ADC-0804 schematic diagram (adc_0804_card.sch, adc_0804_card_S.pdf)
            PCB layout is not too complex because the chip it self only have 20 pins. So the PCB could be made modular. Any input circuitry then locate at the separate PCB layout. This design based on the reference book that I have learned. Some jumper used to select the operational mode. The design is like this :
    ADC card using ADC-0804 PCB layout (adc_0804_card.pcb, adc_0804_card_layout.pdf, adc_0804_card_artwork.pdf)

    3.a. ADC-0804 CARD

            By the time when I made the first card, I also made this card to be implemented on temperature controller project. The card be made universal, so I could use the design later on for the next project. As usual the design must accommodate both for use with personal computer or using it with microcontroller projects. The schematic is like this :
    ADC card using ADC-0804 schematic diagram (adc_0804_card.sch, adc_0804_card_S.pdf)
            PCB layout is not too complex because the chip it self only have 20 pins. So the PCB could be made modular. Any input circuitry then locate at the separate PCB layout. This design based on the reference book that I have learned. Some jumper used to select the operational mode. The design is like this :
    ADC card using ADC-0804 PCB layout (adc_0804_card.pcb, adc_0804_card_layout.pdf, adc_0804_card_artwork.pdf)

    4. ADC-AD7524

            ADC-AD7524 has 8-bit resolution. bla... bla ... bla ...

    5. ADC-0831

            ADC-0831 has 8-bit resolution. bla ... bla ... bla ...

    C. DIGITAL TO ANALOG CONVERTER (DAC)

            DAC used to represent the analog signal state from a digital state or numbers in a limited time interval. Every DAC chip has a resolution and an interval time to represent the state. The higher resolution and the smaller converting time make the chip more expensive. Besides that there are some technique used in the chip to convert the state. But I don't want to deal with the technique. I just want the higher resolution, easy to used and the important things that, it's cheaper!!! What's a hobby!!!

    1. DAC-0800/DAC-0808

            ADC0800/08 chip has 8-bit resolution. Bla ... bla ... bla ...

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    IC TESTER part-1

    Simple function IC tester circuit using bi-directional LPT parallel port or serial port

    LOGIC PROLOG

                What is mean logic-1 or logic-0? Logic-1 and logic-0 strongly connection between the state at one moment and one condition. Logic-1 means any states are in the condition of high voltage close to Vcc voltage, and logic-0 means any states that close to netral or ground voltage. Is that just right that?. What about logic philosophy? Logic philosophy are like this, at one state, logic-0 cannot be made to be come logic-1 but logic-1 can be made to be logic-0. So if we want to exam the output of any devices (like and gate, or gate, not gate, buffer, counter, etc.), the output logic must be keep to be logic-1, then the input logic can be applied and the output logic will be changed by the result.

     

    SALUTATION

                This project was dedicated to Paul Stenning at http://www.paulandmark.u-net.com/electron/ where the idea come when I saw his project. The project used a standard serial port type. I got quiet difficult to find this type IC. So I made the parallel port version. The concept is still the same. I changed only the part of serial to parallel convertion data. But my program still can used both hardware, serial port type or parallel port version. Certainly I didn't try the serial version, because I didn't build it, so if someone have found any bugs, please report it to me. I will fix it. Thanks to Paul because of his great thinking. I myself already tried a long time ago to make a device like this (simple ic-tester) to test any other ICs in my junk trash can. Thank you very much Paul'S !!!

    THE PARALLEL VERSION IC-TESTER

                Some part was changed to accomodate the parallel type port. The original clock circuit, RS-232 buffers and interface was omitted and replace with the parallel port interface and the flip-flop latch changed with 8-bit latch, so the circuit is more simpler. Other parts are still the same accept that the selector switch to select the IC power was changed to relay devices. So we can make the device a little automatic selecting pin power. Here is the complete circuit diagram 

    click the below images for zooming  
     
       
    The device must used bi-directional LPT parallel port (because the standard LPT parallel port can not accomodate the data interchange). All control signals are used to make the combination of control function for PPI-8255. More about explanation for this IC type can be seen at another topic, LPT extender and expander). This IC configured for port-A as output port, port-B as input port and port-C as output port. Port-A used to send logic state to IC under test, port-B used to read logic state from IC under test and port-C used for input decoder to select the enable function of latches and buffers of IC under test and also to activated the relay power circuits. Tabel I-1. shows the functional truth table for operational of this PPI-8255 for our purpose.
     








    A1 A0 RD WR Reset CS Description
    X X X X 0 1  DP side is tri-state (Hi-Z)
    X X X X 1 X  All ports as input ports (reset)
    0 0 1 0 0 0  DP side to port-A (write port-A)
    0 1 0 1 0 0  Port-B to DP side (read port-B)
    1 0 1 0 0 0  DP side to port-C (write port-C)
    1 1 1 0 0 0  DP side to port-CW (write port-CW)
    1 1 0 1 0 0  Not allowed for 8255A-5, but accepted for 82C55 type
     (read port-CW)
    Tabel I-1. Control function of PPI-8255.
     
    -->
                As usual, DP port LPT is used for data interchange, PS port LPT used partly for identify card, and PC port LPT used for controlling the PPI-8255. As for identify card, like EPROM Programmer Card application, I used 2-bits for this purpose. But in that card, PS-7 seems like a redundancy function. Because it is inverting input, so if the PS-7 bit is not connected/released or broken, the reading also true. So I make some advanced used for this PS-7 bit. In this IC-Tester card, this bit used for detecting power-on from the card. If the card is still connected but the power is off, the program can not continue. Please you compare this function with both card. All of PC port LPT are used for controlling. I already selected these bits for our used. PC-5 bit as usual used for bidirectional enable, PC-3 bit used for WR signal (note that PC-3 is inverting input), PC-2 bit used for RD signal (this is normal input), PC-1 bit used for selecting address A1 (note that PC-1 is inverting input) and PC-0 used for selecting address A0 (this also an inverting input). The others functions, reset and Chip Select (CS) enable by used the combination of PC-3 and PC-2 bits. The explanation of these functional utilization can be obtain at LPT extender and expander topic. Tabel I-2. shows the bits should be apply to this port for our purpose as needed by tabel I-1.
     
     








    DP-7 ~ DP-0 8-bit data port
    PS-7 (Inv.) PS-3 Card Identify
    X 0 IC-Tester card detect
    1 X Power-on detect
    PC-7
    (Unused)    		 PC-6
    (Unused)    		 PC-5 (Bidirectional Enable) PC-4
    (IRQ Enable)    		 PC-3 (Inv.)
    Used for WR    		 PC-2
    Used for RD    		 PC-1 (Inv.)
    Used for A1    		 PC-0 (Inv.)
    Used for A0    		 Control port
    X X 0 0 0 1 X X Stand-by mode (Hi-Z)
    X X 0 0 1 0 X X Reset
    X X 0 0 1 1 1 1 Writing port-A
    X X 1 0 0 0 1 0 Reading port-B
    X X 0 0 1 1 0 1 Writing port-C
    X X 0 0 1 1 0 0 Writing port-CW
    Tabel I-2. Bits used by IC-Tester card toward LPT port.
     
                Port PC PPI-8255 (for not to be confused between PC port LPT and PC port PPI-8255, we used the state, PC port is for LPT port and C port for PPI-8255 for later used) are used for activated the latches, buffers and relays for IC test power. 3-bits lower used for binary decoder inputs. So we have 8-state from this 3-bits, 3 are used for latches enable, 3 for buffers enable and 1 for steady-state condition and 1 still spare/unused. Steady state condition used when there are no action or needs when changing state. The rest 5-bits of C port used for enable IC test power. Here I only selected 5 possible and general combination for IC's power pins, range for 24-pins to 14-pins IC. Many TTL's and CMOS's power pins are the last pin number for Vcc and the half pin number for Ground. So for 24-pins IC, ie.pin-12 and pin-24, for 20-pins IC, ie.pin-10 and pin-20, for 16-pins IC, ie.pin-8 and pin-16, for 14-pins IC, ie.pin-7 and pin-14. If we press the ground pin to pin-12, many connection are omitted. The last preserved for un-common combination,ie. if the power locate at another pins, but this is only for IC type less than 24-pins. Vcc locate at pin-24 and ground at pin-1. Connection must be made by manual (jumper). You can use some kind of clips with pointed clip. Fig.1-1. shows one of this clip kinds. For 24-pins IC type, we use nothing of this relay. This also needs manual conection (jumper) to the power circuit. Tabel I-3. shows the control function of C port bits.
     








    C-7 C6 C-5 C-4 C-3 C-2 C-1 C-0 OUTPUT

    		0 0 0 Enable latch data pin-1 ~ pin-8
    0 0 1 Enable latch data pin-9 ~ pin-16
    0 1 0 Enable latch data pin-17 ~ pin-24
    0 1 1 Enable buffer data pin-1 ~ pin-8
    1 0 0 Enable buffer data pin-9 ~ pin-16
    1 0 1 Enable buffer data pin-17 ~ pin-24
    1 1 0 Spare (unused)
    1 1 1 Stand-by mode (steady state)
    1 1 1 1 1
    		User 24-pins IC power select
    1 1 1 1 0 24-pins IC power select
    1 1 1 0 1 20-pins IC power select
    1 1 0 1 1 16-pins IC power select
    1 0 1 1 1 14-pins IC power select
    0 1 1 1 1 User-pins IC power select
    Tabel I-3. Control function of port-C bits PPI-8255.

    HARDWARE

                I already built this prototype by using double sided PCB using protel software design. The design was still crowded, but it worked. Many jumper must be made to both sides, because we didn't have a fabricate one (this create manually). I used a tiny email wire (or you may use wire from nyy cable). Even its already double layer, it needs also many jumper, so don't forget to put it in the right way.

    Here is the PCB artwork looks like (35.800 Bytes).

                Note that the common copper clad of top layer is ground and the common copper clad of bottom layer is Vcc. Don't forget to test it with ohm tester (bell check). this copper side both layer must not short circuited. Also Vcc and ground for any IC must be checked there were connected or not. Its better if we used many socket for ICs, because if any IC known defect, it can be easyly replaced with the new one. Many hours must lost here if you didn't do it well, careful!!! Here also I made PCB adapter (8.349 Bytes) for 20-pins, 16-pins and 14-pins IC to 24-pins socket. View of these adapter constructions are as follow (8.968 Bytes).

     

    SOFTWARE

                Original software written in Quick Basic style, I prever write it in Pascal style (may be later in Delphi for windows based). As usual the hardware can be connected to any LPT parallel port, and the software will automatically checking the card existence. For any one who has already built the serial version, still can use this software. But I did not tested the serial version by myself, please report it if you found any bugs. Below is part of the routine to detect the card, initialization it and routine for I/O transfer, implementation of the description before.
      
    TYPE
    LPT_Port       = (LPT_1, LPT_2, LPT_3, No_LPT);
    Mode_PPI       = (Port_A, Port_B, Port_C, Port_CW, Port_Hi_Z, PPI_Rst);
    Dec_Port_C     = (Set_Latch_1, Set_Latch_2, Set_Latch_3,
                      Set_Buffer_1, Set_Buffer_2, Set_Buffer_3,
                      Set_Spare, Steady_State);
    Mode_Port      = (COM_1, COM_2, LPTs);
    Pin_IC         = (Pin_24, Pin_20, Pin_16, Pin_14, User_Pin, Not_Set);

CONST
     Ada_Port      : BOOLEAN = FALSE;
     Ada_Card      : BOOLEAN = FALSE;
     Bi_Direct     : BOOLEAN = FALSE;
     PC_Port       : ARRAY[0..2] OF WORD =
                     ($03F8,$02F8,$0278);   { 'COM1','COM2','LPT1' }
     DP : ARRAY[LPT_Port] OF WORD = ($3BC, $378, $278, $3BC); { Data Port }
     PS : ARRAY[LPT_Port] OF WORD = ($3BD, $379, $279, $3BD); { Status Port }
     PC : ARRAY[LPT_Port] OF WORD = ($3BE, $37A, $27A, $3BE); { Control Port }
     Port_PPI : ARRAY[Mode_PPI] OF WORD = ($000F,     { Port-A PPI as output port}
                                           $0022,     { Port-B PPI as input port}
                                           $000D,     { Port-C PPI as output port}
                                           $000C,     { Port-CW PPI as output port}
                                           $0004,     { Port-Hi-Z PPI }
                                           $0008);    { Reset PPI }
     Set_Mode_PPI  = $0082;                           { Port-A, Port-C = Output }
                                                      { Port-B = Input, Mode = 0 }
     Set_Dec_Port_C : ARRAY[Dec_Port_C] OF BYTE = ($F8,    { Latch 1 Aktif }
                                                   $F9,    { Latch 2 Aktif }
                                                   $FA,    { Latch 3 Aktif }
                                                   $FB,    { Buffer 1 Aktif }
                                                   $FC,    { Buffer 2 Aktif }
                                                   $FD,    { Buffer 3 Aktif }
                                                   $FE,    { Spare Bit }
                                                   $FF);   { Steady State }
     Tegangan_IC   : ARRAY[Pin_IC] OF BYTE = ($F7,    { Vcc=pin-24, Gnd=pin-12 }
                                              $EF,    { Vcc=pin-22, Gnd=pin-12 }
                                              $DF,    { Vcc=pin-20, Gnd=pin-12 }
                                              $BF,    { Vcc=pin-19, Gnd=pin-12 }
                                              $7F,    { Vcc=pin-24, Gnd=pin-1 }
                                              $FF);   { Vcc=none, Gnd=none, external supply }
     Port_A_PPI    = $03;    { Note that Port-A through Port-CW }
     Port_B_PPI    = $02;    { are inverting to PC-0 and PC-1 }
     Port_C_PPI    = $01;
     Port_CW_PPI   = $00;
    PROCEDURE Cek_Card;
VAR
   Kode_1, Kode_2, Kode_3 : BYTE;
   Dummy : BYTE;
BEGIN
     Ada_Port := FALSE; Ada_Card := FALSE;Bi_Direct := FALSE;
     IF (Set_Port = LPTs) THEN         { Parallel Port }
     BEGIN
          FOR LPT := LPT_1 TO LPT_3 DO
          BEGIN
               IF (NOT Ada_Port) OR (NOT Ada_Card) THEN
               BEGIN
                    IF PORT[PC[LPT]] <> Set_Dec_Port_C[Steady_State] THEN Ada_Port := TRUE;
                    IF Ada_Port THEN
                    BEGIN
                         PORT[DP[LPT]] := $44;        { Send code byte 'Dummy' }
                         Dummy := PORT[PC[LPT]];
                         PORT[PC[LPT]] := Dummy OR $20;    { Cek bi-directional port }
                         IF PORT[DP[LPT]] <> $44 THEN Bi_Direct := TRUE;
                         PORT[PC[LPT]] := Dummy;
                         IF Bi_Direct THEN
                         BEGIN
                              IF ((PORT[PS[LPT]] AND $88) = $80) THEN Ada_Card := TRUE   { Cek IC-Tester Card }
                              ELSE Ada_Card := FALSE;      { PS_3 = normal, PS_7 = Inverting }
                         END;                              { When open, PS are all in hi-z }
                    END;
               END;
               IF Ada_Port AND Ada_Card THEN     { Normally PS[LPT] = $7F (?) }
               BEGIN
                    Port_DP := DP[LPT];
                    Port_PC := PC[LPT];
                    Port_PS := PS[LPT];
                    IF Bi_Direct THEN Inisialisasi_PPI;
               END;
          END;
     END;
END;

PROCEDURE Inisialisasi_PPI;
BEGIN
     IF Set_Port = LPTs THEN
     BEGIN
          PORT[PC[LPT]] := Port_PPI[PPI_Rst];    { Give a pulse }
          PORT[PC[LPT]] := Port_PPI[PPI_Rst];    { Give a pulse }
          PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_CW_PPI;
          PORT[DP[LPT]] := Set_Mode_PPI;
          PORT[PC[LPT]] := Port_PPI[Port_CW];    { Give a pulse }
          PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_CW_PPI;
          PORT[DP[LPT]] := Set_Dec_Port_C[Steady_State];
          PORT[PC[LPT]] := Port_PPI[Port_C];     { Give a pulse }
          PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_C_PPI;
     END;
     Temp_Port := Set_Port;
END;

PROCEDURE Tulis_Port_A(Datanya : BYTE);
BEGIN
     PORT[DP[LPT]] := Datanya;
     PORT[PC[LPT]] := Port_PPI[Port_A];     { Give a pulse }
     PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_A_PPI;
END;

PROCEDURE Tulis_Port_C(Datanya : BYTE);
BEGIN
     PORT[DP[LPT]] := Datanya;
     PORT[PC[LPT]] := Port_PPI[Port_C];     { Give a pulse }
     PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_C_PPI;
END;

FUNCTION Baca_Port_B : BYTE;
VAR
   Temp : BYTE;
BEGIN
     PORT[PC[LPT]] := Port_PPI[Port_B];     { Give a pulse }
     Temp := PORT[DP[LPT]];
     PORT[PC[LPT]] := Port_PPI[Port_Hi_Z]+Port_B_PPI;
     Baca_Port_B := Temp;
END;
              
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