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  1. BobK

    Electrolysis hho generator

    Water separated into hydrogen and oxygen. Many falsely believe you can get more energy back by burning it than it took to separate it. Which is nonsense. Bob
  2. BobK

    Circuit recommendation?

    A single 555 can blink them either together or alternately. Bob
  3. BobK

    Why is this Happening to Me?

    I find stripboard or veroboard to be the most error prone method of building things. For any permanent circuit I make a PC board. In this case the software can check every connection against the schematic, so it pretty much never comes out connected wrong,though I often end up having to add a...
  4. BobK

    Circuit Board coding

    I must be misunderstanding something. In order for the holes to be labelled the same, the letters must be backwards on the flip side. In other words, if you flip the board you show left to right, the letters must appear as: TSRQ ... CBA Which is what you said was the case. Bob
  5. BobK

    Kid's battery operated car stopped moving

    I think the new switch should go between the two red leads that went to one original terminal and the red and blue leads that go to another terminal. If you used the black lead in wiring the new switch I suspect that is wrong. But please do not make that change without further investigation...
  6. BobK

    Kid's battery operated car stopped moving

    And how did you wire the new switch. The fact that there are two wires (red, blue) going to the third terminal makes me think there is something more going on there than just a lighted switch. Bob
  7. BobK

    does anyone understand microphone wiring

    This is a likely a dynamic mike with no active circuitry. The switch is shorting the mike output. Most likely dirty contacts as someone else stated. Bob
  8. BobK

    Replace Photoresistor with Solar Cell

    If you solar cell puts out more than a half a volt, it is actually multiple cells in series. In this case, all of the cells must be activated ti get an output. In other words, illuminating a small part of the solar panel with a laser dot will not work. Bob
  9. BobK

    Solenoid Motor Strength

    Yep, as I suspected, there is a far better way to do it. Bob
  10. BobK

    Solenoid Motor Strength

    Now, how about telling us what it is you are trying to accomplish with your solenoid. There is very likely a better way to do it. Bob
  11. BobK

    Value of this crystal?

    What makes you think it’s a crystal? Normally, a crystal has 2 pins. Bob
  12. BobK

    Coronavirus transmission prevention device.

    I thought I would get a comparative fatality rate for riding in cars for a lifetime. There are about 1.25 deaths per 100,000,000 vehicle miles. As a rough estimate, a person might ride about 1,000,000 miles in a lifetime. So, the probability of death would be about 1% for the average person...
  13. BobK

    My new multimeter

    I hope you have a good supply of 45V batteries for those high resistance readings! Bob
  14. BobK

    Next Smoke Detector Millionaire or Not?

    The ones with 10 year lithium batteries have made it less of a concern. I suspect that rechargeables are not seen is based on not being certified because the cannot meet reliability standards. Bob
  15. BobK

    Common Emitter Amplifier - Class B

    When you quoted the definition, you said nothing about sine waves. What other secret rules do you have? Bob
  16. BobK

    Common Emitter Amplifier - Class B

    That definition is not very useful. Consider a symmetric square wave with 90% of the cycle positive and 10% negative. Would a class B amplifier conduct over half the cycle? Bob
  17. BobK

    Best course of action for high current DC supply

    Assuming you are correct that your cells can output 20A, then the fuse needs to be for about 25A, not 300 to 600A since the fuse is seeing only the current of one cell. Bob
  18. BobK

    Common Emitter Amplifier - Class B

    Not much of an amplifier if it ignores half of the signal. Maybe it's a class B half-amplifier. Bob
  19. BobK

    Common Emitter Amplifier - Class B

    A class B amplifier requires 2 transistors, 1 for the positive half and one for the negative half of the signal. One a PNP and the other an NPN. Bob
  20. BobK

    Led blinking instead of staying solid

    Um... red LEDs are more like 2.2V not 1.2. Then the calculation becomes 2.8 / 0.02 = 140 Ohms. But I would design for a lot less than 20mA. Any modern LEDs will be very bright at 20ma, and are okay for indoor use at 1mA. Bob
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