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  1. AnalogKid

    Prevent Transistor Leakage

    Depends entirely on the load. Yes. No. Yes. But your initial premise is incorrect in two ways. First, "off" is a relative term, not an absolute. Because if its internal design, a load might quit drawing current when its source voltage is below a certain value, even if that value is...
  2. AnalogKid

    ESD Protection - Design Consideratons

    Again, you're off by over 50 years. A giant leap in ESD awareness happened with the first solid state devices and products, and became a critical part of device handling and circuit design with the introductions of, first, insulated gate FETs (50s), and second, CMOS (60s). In fact, it is...
  3. AnalogKid

    Altec Lansing 221 Woofer volume control.

    I agree. If you can trace the input back to its source, probably the output of an active filter opamp circuit, then you will get better results and better adjustability if you modify the signal at a low power point rather than at the high power output. ak
  4. AnalogKid

    Video Switcher

    If the OP still is interested, and confirms that all video signals are composite NTSC, then Maxim has many video mux chips. Also, there are very inexpensive video mux products on ebay, and many are remote controllable through a serial port. ak
  5. AnalogKid

    USB led lamp project

    Please provide the datasheet for the LED. ak
  6. AnalogKid

    Delayed buzzer for Motorbike

    25 V or more. A good rule to follow for most designs is that a capacitor should be rated for at least twice the peak voltage across it. ak
  7. AnalogKid

    Delayed buzzer for Motorbike

    This thread would have been much better if you had included this drawing in your first post. Your drawing matches up very will with my circuit. "blinker input" connects between the Turn Signal Flasher and the Turn Signal Switch. "blinker power" connects between the Ignition and the Turn Signal...
  8. AnalogKid

    Delayed buzzer for Motorbike

    That was suggested in an earlier post, and depending on how the bike is assembled and wired it might be an easier installation, but then you have to have enough energy storage to run the circuit and the beeper during the OFF half-cycle of blink #10. Seemed to me to be an unnecessary...
  9. AnalogKid

    Delayed buzzer for Motorbike

    The circuit is based on assumptions about how a motorbike is wired. When you activate either a turn signal or the safety flashers, that applies 12 V to the flasher or blinker device. This is where you connect the power input to the circuit (blinker power). All ground symbols connect the the...
  10. AnalogKid

    Delayed buzzer for Motorbike

    Protecting circuits from lightning strikes is entirely doable, but it takes attention to some...uncommon...details. MIL-STD-464 defines a lightning strike as a 218,810 ampere transient that drops to 11,300 amperes for 5 milliseconds, then settles down to 400 amperes for 1/2 second. That's a...
  11. AnalogKid

    Delayed buzzer for Motorbike

    As the internal schematic of the 4017 shows, the enable (or inhibit) input gates the clock only, and has no effect on the reset function. In fact, you can use the enable input as a negative-going clock input and the clock input as a positive-going enable. Experience indicates that CMOS...
  12. AnalogKid

    Delayed buzzer for Motorbike

    R1 and C3 form a power-on reset. The circuit powers up every time a turn is initiated, and the 4017 is not guaranteed to start in any particular state. D2 and D3 work with R2 for input transient suppression. I assumed that bike signals are at least as dirty as car signals. There is a simple...
  13. AnalogKid

    Delayed buzzer for Motorbike

    That is what the OP requested. ak
  14. AnalogKid

    Rotating Solar Panel Mount/Limit Switches

    There is a solar farm sprinkled around DIA, and each row of panels has an articulated arm moving the entire row all in unison. Don't know if it is motorized or just a basic mid-day alignment. ak
  15. AnalogKid

    Delayed buzzer for Motorbike

    Something like this. ak
  16. AnalogKid

    Delayed buzzer for Motorbike

    You want the circuit to be powered by the battery *after* the ignition switch, so it isn't drawing any current when the bike is off. Then, the circuit board needs inputs from both the input and output sides of the turn signal blinker. These get cleaned up with a noise filter and transient...
  17. AnalogKid

    Rotating Solar Panel Mount/Limit Switches

    Your plan is sound, and there are many waterproof industrial switches. Or, you can use the magnetic reed switches designed for home alarm systems. These are hermetically sealed by design, and relatively low cost. Put the magnets on the moving part and one reed switch at each end of the travel...
  18. AnalogKid

    conversion of dc voltage to dbm meter as display

    That's a good idea. ak
  19. AnalogKid

    Ground loop filter

    Yes, an optoisolator will work. The problems is that both the conversion from current to light, and light to current and non-linear and not complimentary. So as a simple interface device similar to a transformer, harmonic distortion is added to the signal. There are circuit design tricks to...
  20. AnalogKid

    Building a custom frequency generator

    And now, some real fizix - EC=IT If a capacitor is discharged with a constant current load, this very simple equation tells you how long the cap can run things. If your cap is charged up to 12 V, and the device you are powering must have at least 10 V to function, then E = 2 V, the amount of...
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