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  1. (*steve*)

    Low voltage output.

    You need to hope that the microcontroller is not damaged. Whilst you can possibly get a replacement, you won't get a replacement with the required program on it.
  2. (*steve*)

    HP 6434B DC Power supply repair! Help

    In answer to your earlier question, with a 1.6ohm resistor, the current which will flow is V/R, or V/1.6. That's approximately 0.6V which gives 24A at 40V -- which is what you observed. The analog meters site the actual voltage and current, not the maximum they are set for.
  3. (*steve*)

    HP 6434B DC Power supply repair! Help

    Yep, that is correct.
  4. (*steve*)

    OPA in mic preamp

    And thirdly, what is "OPA"?
  5. (*steve*)

    OPA in mic preamp

    Also, many of the component designations are duplicated. You could add 100 to one channel and 200 to the other so that instead of having two R4's, you have an R104 and an R204.
  6. (*steve*)

    OPA in mic preamp

    R2/c3 are your problem. The lower end of r2 needs to go to a 0V rail. You need to split your power supply to be +/- 4.5V, or perhaps more easily, change it to +/- 9v (using 2 9V batteries). Take a look at typical audio amplifiers using op amps and see how it's done.
  7. (*steve*)

    Designing of USB interfacing board for FTP-628 FPC thermal printer

    According to that datasheet there is an interface board and cable available for a USB interface.
  8. (*steve*)

    Power bank PCB

    It is probably worth speaking to a manufacturer or distributor of these devices. You may get a good discount on this quantity. Do these all have to be separate, or will they be in one enclosure?
  9. (*steve*)

    HP 6434B DC Power supply repair! Help

    To test higher current ranges, you can probably apply a short to the output. The instructions probably suggest that :)
  10. (*steve*)

    HP 6434B DC Power supply repair! Help

    You need a lower value resistor in order for the current to rise to more than 0.6 x voltage.
  11. (*steve*)

    RGB Led cube and more..

    I'd also recommend you read this: http://www.instructables.com/id/Led-Cube-8x8x8/step1/Software-Effect-launcher/ Understand the complexity of a 1 bit 8x8x8 cube, and then contemplate that you are asking for a 24bit 8x8x8 cube. Not only will the wiring be 3 times as complex (for the three...
  12. (*steve*)

    Trouble understanding shunt resistance for short-circuit current measurement

    Another option for the bipolar device is to connect it inside an H bridge. You take as your current measurement the difference between the forward and reverse reading. This gives you one extra bit of resolution and cancels out the zero point out any drift in it. It's not suitable for rapidly...
  13. (*steve*)

    Dr Who's K9 circuit help...

    If you notice my initial description of what you need, it said the function for the text needs to do just one column and return. Yours does all columns (or all something). In the function that you call every 50ms, it must remember where it's up to and either so the next column and return or...
  14. (*steve*)

    Dr Who's K9 circuit help...

    One thing you've forgotten is the { ... } after the if statement to contain the block of code to execute when the test is true. Without this only the line filtering out is affected.
  15. (*steve*)

    555 timers

    Which are now available on that new fangled interweb thingy.
  16. (*steve*)

    Trouble understanding shunt resistance for short-circuit current measurement

    I have a clamp on dc ammeter that has exactly the same feature on the low current ranges. And, as a coincidence, it has valves!
  17. (*steve*)

    Help! Advice?

    It is possible that a fault in your device has caused a short between an input power connection and the internal low voltage power supply or ground. If so, then reversing the power connector could change that from a relatively benign connection to ground to a far more dangerous connection to...
  18. (*steve*)

    Help! Advice?

    Does it have a 2 pin plug that can be connected either way around?
  19. (*steve*)

    motors start when i touch arduino port

    There are just so many possibilities. You may have configured the pins as inputs and you are driving mosfets. Any significant charge on your body could turn the mosfets on (or off). Or you may have programmed your arduino to respond to signals on other pins. Without activating the internal...
  20. (*steve*)

    need to make a circuit

    Very simply. The load you are switching must draw no more than 4A.
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