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  1. AnalogKid

    Capacitor rated voltage question.

    An overvoltage of putting 16 V on a cap rated for 10 V probably will not explode. It will shorten its life span. The rule of thumb for most electronic components is to run them at 50% of their ratings. So keep the 10 V cap under 5 or 6 volts, a 60 V transistor at 30 V or less, etc. The...
  2. AnalogKid

    Digital multimeter without Rotary switch.

    Yes. Most bench instruments have push buttons. http://www.paleotechnologist.net/?p=2400 ak
  3. AnalogKid

    Maximum value of Potentiometer.

    Please post your schematic so we can see what you are talking about. Be sure to have a reference designator for each component and show all power sources. ak
  4. AnalogKid

    Maximum value of Potentiometer.

    It could be 1 ohm. It could be 10 million ohms. Your question makes no sense. Which potentiometer are you talking about? Part number? Application? Schematic? ANYTHING? ak
  5. AnalogKid

    9 way clap switch

    Look at the photo again. ak
  6. AnalogKid

    Bistable relay as monostable - why 2 transistors ?

    Your image did not come through. The purpose of the 10K resistor is to make sure T2 turns off rather than leave the base floating when T1 is off. ak
  7. AnalogKid

    9 way clap switch

    1. Post your schematic and parts list. Your photo has no part numbers, no component values, and no other useful information. Also, what is a 9-way clap switch? There is only one microphone visible, no relay, and no power supplies or batteries. What is it the circuit is supposed to do? ak
  8. AnalogKid

    Bistable relay as monostable - why 2 transistors ?

    The circuit in post #1 is not a standard 2-transistor bistable latch. There is no latching except what is done electromechanically inside the relay. Both transistors are either on or off at the same time. The transistors are two saturated switches in series. The only reason for two of them...
  9. AnalogKid

    PCB Connectors

    Photo of board? Accurate dimension of hole spacing? ak
  10. AnalogKid

    Help me in schematic diagram...

    First pass at a non-lethal circuit. This one requires a DC-output wall wart as the AC power fail detector, plugged directly into the mains. The filter capacitor in the wall wart acts as a time delay to prevent shutting down the server during brief power interruptions. The circuit uses one of...
  11. AnalogKid

    Help me in schematic diagram...

    Assuming the on/standby switch is SPST with a short 2-wire harness going to a 2-pin connector on the motherboard, please measure these three voltages with the computer running: Switch pin 1 to pin 2 Switch pin 1 to system GND Switch pin 2 to system GND. ak
  12. AnalogKid

    Where did the - 0.7 V from the graph came from? (Diode Clampers Circuit)

    No, I'm referring to forward current when the diode is forward biased. When the diode is reverse-biased, the current through it is essentially zero, and there is a current path through the capacitor and the load resistor. When the diode is forward biased, the voltage across the resistor is...
  13. AnalogKid

    Help with diode replacement

    That looks like the ON Semiconductor logo. 9258 probably is the date code. ak
  14. AnalogKid

    Where did the - 0.7 V from the graph came from? (Diode Clampers Circuit)

    Not quite. There will be current through the load resistor (and the capacitor) whether the diode is forward biased or not, only the mount of current through the resistor changes between the forward and reverse biased conditions.
  15. AnalogKid

    Help me in schematic diagram...

    I'm not comfortable posting a circuit that can kill you in a forum called "Homework". Do you have an unused wall wart that can be used as part of the AC-fail detector? Smaller is better, but any size, any output voltage will work. ak
  16. AnalogKid

    Help me in schematic diagram...

    Neither of my Win7 systems behave that way. The relationship between the on/standby switch and the power supply is controlled by the motherboard hardware and the BIOS, not the operating system. Is this for a school project? ak
  17. AnalogKid

    Help me in schematic diagram...

    On all of my recent computers, you have to hold in the on/standby switch for at least 4 seconds before it turns off the power supply. How quickly does your motherboard react when you push the switch? ak
  18. AnalogKid

    Help me in schematic diagram...

    The way it works is that the on/standby button goes to a circuit on the motherboard, and that circuit drives the enable signal to the power supply. Because we don't know exactly what that motherboard circuit is, the safest thing is to connect the output of an optocoupler in parallel with the...
  19. AnalogKid

    Why are actuators inductive?

    Because electromagnetic force is much easier to produce and contain than electrostatic force. ak
  20. AnalogKid

    Timed latch

    The basic flow is this: 16 Vac Doorbell wiring > Opto coupler > Timer input > Timer output relay > AC power switched to the monitor wall wart - or - Wall wart DC output power switched to the monitor 1 minute is a bit long for a 555-based timer module, but there should be some on ebay that go...
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