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  1. AnalogKid

    The 2 capacitor paradox

    Does it ever occur to you that no one has any idea what you are talking about? ak
  2. AnalogKid

    Potentiometer with two extra connectors

    Nope - switch. ak
  3. AnalogKid

    15 pin Sub-D power supply/control help

    Re-read your first post. ak
  4. AnalogKid

    15 pin Sub-D power supply/control help

    Of the many things you left out of your question, the most important is that you have a ******stepper***** motor. This is not a simple DC motor. It requires specifically times pulses on its inputs, in a certain order. https://en.wikipedia.org/wiki/Stepper_motor You don't say what the pump...
  5. AnalogKid

    15 pin Sub-D power supply/control help

    Was it this pump or that pump? Please re-read your question, and think - is there ***anything*** here that is needed to answer a question? Things like labels, power connections, a photo, the manufacturer, model number - - ***anything*** ? ak
  6. AnalogKid

    Phantom power mic problem

    It is possible that the interface is supplying DC on one wire only, because that is all a condenser mic needs and its output is not balanced. If you do not have balanced DC on both wires, a dynamic mic element will saturate - the diaphragm will be either pushed all the say out or pulled all the...
  7. AnalogKid

    Looking for guidance on CRT TV repair

    Looks like the vertical blanking might be adjustable through the remote control. ak
  8. AnalogKid

    Looking for guidance on CRT TV repair

    The three beams sweep horizontally very quickly while they sweep vertically relatively slowly. When they reach the bottom of the screen, then are blanked( turned off) and yanked back to the top of the screen quickly, during the "vertical blanking interval". So rather than zig-zag downward...
  9. AnalogKid

    Designing differential Signal modulator.

    Maybe. My read of the schematic is two separate oscillators that are gated on and off with the two phases of an input square wave. To me that doesn't match the written description, but that might be a translation problem. However ... Note that because you are gating the oscillators on and...
  10. AnalogKid

    Will a voltage divider waste power?

    Don't encourage him.
  11. AnalogKid

    Circuit help: momentary bi-directional DC motor control

    The way the question is written in post #1, it sounds like you want the motor to run for 2 seconds after all circuit power is removed. That can be done, it you add in a large capacitor that can store enough charge to run the motor for 2 seconds. Your problem is much more simple if the circuit...
  12. AnalogKid

    Circuit help: momentary bi-directional DC motor control

    The thing about running a motor both directions on a timer is that the motor will not return to the exact same position each time. Over time, the rest position might creep far enough out of place to be a problem. For whatever the motor is moving, are limit switches a possibility? ak
  13. AnalogKid

    Don’t know what I’m doing Amp project. Help!!

    Anyone have any links to product pages? Or photos? Anything with writing on it. any connectors. What are you using to measure voltages? If it is a meter, is it on an AC or Dc scale? It's kinda important. "Big transformer thing" is a relatively useless description. If if is an open-frame...
  14. AnalogKid

    How to limit amplifier output power

    A bypass cap would not "get rid of" the load, it would increase it. ak
  15. AnalogKid

    How to limit amplifier output power

    A single 6 ohm resistor in series with a 4 ohm speaker will dissipate 60 W when the speaker is dissipating 40 W, adding up to 100 W and solving the problem. It also will increase greatly the effective output impedance seen by the speaker, so the speaker will ring more on transients. As above...
  16. AnalogKid

    Help with 555 latch circuit

    100K and 1 uF is a time constant of only 0.1 s. This will not register on a meter. The intent of the circuit is that there is an intentional voltage spike on the 555 inputs caused by the capacitor when it is fully charged up by the 555 high output. But the 5 K input impedance caused by the...
  17. AnalogKid

    Help with 555 latch circuit

    The original 555 device (NE555, LM555, MC555, etc.) is a bipolar device. If you read the datasheet, you will see that the output does not go all the way up to Vs (should be called Vcc) under any conditions, and especially when it is trying to source 11 mA into a load. The CMOS 555 (LMC555) has...
  18. AnalogKid

    LM339/LM339N can't get output high

    Yeah, I was gonna mention that. In this particular circuit, shorting unused outputs to GND will not harm anything because they are open-collector. But as generic advice it is *terrible*. And, in this particular case shorting the inputs to the negative rail is not a problem because these...
  19. AnalogKid

    LM339/LM339N can't get output high

    Please post a real schematic for your circuit. Be sure to use a symbol for each comparator, not a box with a bunch of lines. Also, include reference designators so we can discuss the components individually. ak
  20. AnalogKid

    multivibrator circuit

    There is nothing in the circuit to lock it to any specific frequency. The high frequency limiting factor is the core material in the transformer. Grain-oriented steel, standard for 50/60 Hz power transformers, is not very fast. This is why switching power supplies use various ferrite...
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