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  1. MP1

    0-30 Vdc Stabilized Power Supply

    All the components around the IC are for the current limiting circuit. You should check all of these parts for correct values and orientation. Did you leave anything out that you felt was not needed? Even the LED is part of the current limiting circuitry. MP
  2. MP1

    Frost Alarm

    Rocky, here is the complete data sheet (attached) There is no difference in pin out for UA741 or LM741 in case you are wondering. MP LM741.pdf
  3. MP1

    Help with 60 second stopwatch project

    What you are referring to is a MOD-60 or MODULO-60 counter. You can use a MOD-10 counter with one of the 74LS93s and a MOD-6 counter with the other to provide a MOD-60. Here are some links. Some are ppt, so the download will take a while. The time to wait is worth it, though. Great examples and...
  4. MP1

    Component dimensions chart

    Billy, I came across this page the other day from my archives. I used to have this on my website when I was manufacturing boards. Perhaps the information will be useful to you. You will want to convert the inch references to mm. This is information on how to determine the hole size versus the...
  5. MP1

    Help with code transmission in RF or IF

    There is a project in the project section of this site for a laser transciever. It might be a good building block. You can use a microprocessor to send the signal. MP
  6. MP1

    project ideas

    since you must have mechanical control and PIC, I suggest that you use a PIC to make a stepper motor move with some type of control for CW and CCW or speed. MP
  7. MP1

    Unipolar Stepper Motor Controller using UCN5804

    In further investigation, it looks as though the data sheet diagram for internal circuitry is not quite right. Where it shows ground, must have some resistance built in that the manufacturer is not showing. If you look at the example circuit given in the data sheet, it also shows the power...
  8. MP1

    power vs. signal frequency

    Yes, a schematic would be very helpful. I think that you are still going to have a problem with inductance characteristics. Filtering is going to be essential to make it work. MP
  9. MP1

    Timer help

    Actually, the 555 timer time event only functions from the RC circuit triggering it. There is no problem with the 555 timer circuitry for longer time delays. Where most people have a problem with the 555 timer, it is usually traced to the external circutry. You can add a a transistor and usually...
  10. MP1

    Diodes for Infrared Gate

    The schematic would imply that the center diode is the transmit LED, which has a good current rating with the resistor used at low volt. (Most IR projects use 3V.) The schemtic would also imply that the other two devices are 'receive' since the schematic symbol is pointing the arrows toward the...
  11. MP1

    Sine wave power inverter

    Yes, the true sine wave is the appealing part of this. The part I am currently struggling with is the current loss when using a step up transformer that is not expensive. Anyone have a good schematic that they would like to share? MP
  12. MP1

    power vs. signal frequency

    Actually, there are network devices that use your power lines of the house to communicate on. The AC is filtered out at the other end. Another example is the ABS brake system on most cars. The sensor sends an AC signal to let the processor know the wheel is moving and a DC signal is also...
  13. MP1

    Sine wave power inverter

    John, do you know where that circuit is? A link? It sounds very similar to one I am making now. It would be great if I could compare what someone else has done already. MP
  14. MP1

    led lighting

    Darinyou, this is just qbasic or similar. You might have this already on your computer depending upon which version of operating system you have. I think at some point microsoft quit putting qbasic in the package. Win98SE did not install the program automatically. All operating systems newer...
  15. MP1

    electronic parts

    evume, what is the problem with getting the parts? Is it government regulation? Vendor refusal to send them? Payment methods? Problem with certain shipping companies? Members of this group will need to know as they might have the same problems getting the parts to you. For example, you cannot...
  16. MP1

    Led display Digital Voltmeter question

    Here is a circuit that might help with the negative supply. Easy to find parts. You might have to tweak the values a little for your application. MP
  17. MP1

    Rolls-Royce Show Engine Motor Controller

    I agree. We are just shooting in the dark without more information. What model is the motor? Any links on the web where we might get more information? MP
  18. MP1

    Rolls-Royce Show Engine Motor Controller

    What you might be looking at is a Throttle Position Sensor (TPS). This is used to tell the on-board computer the position of the pedal in order to make other decisions such as what gear to change in the auto transmission or to richen the fuel mixture. I am not familiar with this particular...
  19. MP1

    Serial IN,Parallel Out

    The 74HC595 chip works very well since you can go parallel to serial or serial to parallel with a logic change. MP
  20. MP1

    0-30 Vdc Stabilized Power Supply

    Think of the commas as periods or the periods as commas. These are used differently in different continents. It means the same. MP
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