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  1. C

    Learning Electronics, need help with my noob circuit

  2. C

    need to determine the strike voltage of a fluoro tube

    You must make yourself clear. Are you talking about lowest line voltage or lowest strike voltage???????
  3. C

    need to determine the strike voltage of a fluoro tube

    "I suggest using a variable transformer, e.g. an autotransformer that is designed to deliver at least 60W to a load. You can then adjust the voltage to the lamp by setting the transformer accordingly." This not what I considered the request to be.
  4. C

    need to determine the strike voltage of a fluoro tube

    It ranges from something over 300v to about 750v, depending on if you are heating the ends. And it depends on how much "kick" you have in the voltage and how fast you want the tune to "fire." It also depends on the pressure of the gas as there is a difference between fluoro and CFL.
  5. C

    Wheel of FORTUNE HELP

    You can't connected LEDs in series without a resistor
  6. C

    SN74HC595N Shift Register Problem

    It has to be done with a micro and PWM because the whole thing is an illusion.
  7. C

    How to protect Metal Halide Bulb from burning

    Disregard my posts. I was thinking of the Halogen lamps.
  8. C

    How to protect Metal Halide Bulb from burning

    Use a 2R2 at 10 watt will make an enormous difference as the starting resistance of the lamp is about 10 ohms.
  9. C

    Help with voltage follower

    First he doesn't need accuracy, then he wants an INSTRUMENT AMPLIFIER ACCURACY. He's only driving LEDs !!!! You're going to have to do a lot of fancy footwork to get a 0v - 10v into a 0v - 12v output with an op-amp. He just needs a Sziklai Pair...
  10. C

    Help with voltage follower

    In circuit #4 you are not gaining anything by adding the op-amp. Just use the emitter-follower transistor.
  11. C

    Detecting spike from DC relay

    Put your fingers across the relay.
  12. C

    How to protect Metal Halide Bulb from burning

    A resistor such as 3R3 or 4R7 at 10 watt will increase the life enormously.
  13. C

    My Project motor driver Smoked what driver i really need ?

    None of the parts on that board have any heatsink and none of them look like they will handle anything more than 1 amp.
  14. C

    Small Microphone transmitter

    Why did you try this circuit ??? I said the circuit did not work: Before we go to an improved design, here is an unusual circuit using a PNP (BC 557) transistor. Firstly, PNP transistors do not work as well as NPN transistors. I would reverse the 4k7 and electret mic as the voltage between...
  15. C

    Circuit to indicate charge remaining in any battery bank

    That's what the carbon-pile battery testers do but they are big, expensive and dissipate an enormous amount of heat.
  16. C

    Circuit to indicate charge remaining in any battery bank

    "You can also build a circuit to measure the amperage capability of a power pack." How can you do this ????? I will buy 1,000 of these !!!!!!.
  17. C

    Confused about a DC Motor

    Here is a very clever circuit to provide a constant speed for a small motor. You may have to modify the circuit as your motor has a very low armature resistance. "Of course. With the motors I am using they will not run much below 30% duty cycle. There will always be a minimum to start the...
  18. C

    Confused about a DC Motor

    "PWM is not the equivalent of using a lower power supply or inserting a resistor because the a higher current is reached during the on portion of the PWM cycle." But when the "ON" portion of the PWM is very short, the motor will not start, just like the problem with adding a resistor.
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    Confused about a DC Motor

    PWM is very similar to adding a resistor in series with the motor, as far as reducing the RPM is concerned, but as you have found out, adding a small resistance completely stops the motor revolving. This is very unusual for a 3v motor and it seems your motor has very few turns of thick wire on...
  20. C

    testing capacitors

    A very poor multimeter. The actual max capacitance is not specified but it has a reference to 100u. You can buy the meter on Amazon: 1 new from $32.95 1 used from $45.00 5 broken from $65.00 I would buy all the broken meters. The only way to measure electrolytics above 100u is to...
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