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  1. crutschow

    Help needed - bilge pump alert

    To me, adding that tap and hose is more work than adding a very simple circuit. And the circuit gives you a remote indication. Long live the deciBel.
  2. crutschow

    Need Help to design a simple blinking LED Circuit using a 9 volt battery

    That time period is too long for a 555 timer. If you are up to a little circuit fab, a variation of this circuit using the CD4060 should work.
  3. crutschow

    Help needed - bilge pump alert

    Not sure what would be "best" but a simple way, with no electronics, is a 12V dual-coil latching relay that lights the lamp. Cheaper, but slightly more complex, would be circuit with a latch, such as a CD4013 flip-flop driving an LED. Your choice.
  4. crutschow

    How to achieve maximum power output from a center tapped transformer.

    Does for me. Thanks.
  5. crutschow

    How to achieve maximum power output from a center tapped transformer.

    No confusion on my part, but apparently yours. Where did I suggest you get more power out then you put in, which is obviously impossible. The power and current from the transformer are the same, but a lower voltage at a given current will have less power. The output power will thus be slightly...
  6. crutschow

    How to achieve maximum power output from a center tapped transformer.

    That is quite obvious. I never said otherwise. I didn't mentioned transformer power, I'm taking about the DC power output. A standard diode bridge has slightly more power loss than a Schottky bridge so it will output slightly less power.
  7. crutschow

    How to achieve maximum power output from a center tapped transformer.

    I obviously meant DC output power, not transformer power.
  8. crutschow

    How to achieve maximum power output from a center tapped transformer.

    Using the bridge with a center tap gives you a plus and minus output voltage. Using the voltage from each side of the bridge output, and not using the center-tap, will give you a single output at twice the voltage. Either way will give the maximum DC power you can get from the transformer...
  9. crutschow

    current surge stalling engine

    Even if that were a 10W pot (which is not stated). the maximum current the internal wiring could carry would be 22mA, many orders of magnitude below what you need. If you learn Ohm's law, plus the equations for power (P = V x I, P = V² / R, and P = I² x R) where P is power, R is the...
  10. crutschow

    current surge stalling engine

    20,000Ω is way too high a resistance. That will limit the current to a fraction of an amp. Do you not know Ohm's law, which states that Current = Volts divided by Resistance? This 50W resistor selected with 0.5Ω should work. It should limit the maximum current to <10A with the battery attached...
  11. crutschow

    current surge stalling engine

    Why do you think that? The alternator should handle the sudden full-load without a problem.
  12. crutschow

    current surge stalling engine

    Have you tried connecting the load with the engine at idle, and then increasing it's speed?
  13. crutschow

    A really small and cheap audio stereo amplifier 3w/3w from 5V psu

    That will only do 3W with a 5V supply if you are using a 4Ω speaker.
  14. crutschow

    current surge stalling engine

    What do you mean by "energize"? Does the alternator have a separate voltage regulator or is it built in? If you can access the field wire, you can add a resistor in series to reduce the field current which reduces the alternator output voltage/current.
  15. crutschow

    replacing 24v motor with 48v motor in existing system

    That duty-cycle is likely for less than 3 minutes of ON time, more like the time it takes for a garage door to operate.
  16. crutschow

    replacing 24v motor with 48v motor in existing system

    As an alternate to a gear mechanism, you might consider a small, cogged timing belt with a 2:1 pulley configuration.
  17. crutschow

    VARIAC? With valves!

    That certainly is not a Variac as the term is now used (for an adjustable autotransformer that allows the output voltage to be varied). From the label, it appears to give a stable 230VAC output within 0.15% (!) for a 200-250VAC varying input voltage from the mains (which was probably typical of...
  18. crutschow

    Creating a 9VDC adaptor for my multimeter.

    You could also consider a rechargeable 9V.
  19. crutschow

    Variable psu troubleshoot

    What do you mean "amp not going back down"? Need more exact info about the problem you are having.
  20. crutschow

    current limiter

    Below is the LTspice simulation of a simple, 2-transistor circuit that should not oscillate and should do what you want. It uses the base-emitter voltage of Q1 as a reference for the current limit. The limit is about 0.65V / R3. The load current increases until the voltage drop across R3 starts...
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