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  1. BobK

    I need to hire someone for a logic design

    It's really pretty simple nephew Chris (since Bob is your uncle, and Martin's great uncle.) You have container open at the bottom a mixture of air and water in it. The air will be at the top. The mixture is just enough to make it float to the top under normal pressure. The container is in a...
  2. BobK

    120v dc power supply

    That chip is not a MOSFET, nor even a MOSFET driver. It is a driver chip for a complementary darlington output stage. Also, the max voltage allowed is ±100V, but you don't need that much unless you want 600W into an 8Ω speaker. Bob
  3. BobK

    120v dc power supply

    The schematic clip you posted shows +Vcc and -Vee and ground. That is a bipolar power supply. Bob
  4. BobK

    Making new AC DC transformer for La Z Boy chair

    You can use size to estimate the power of a transformer. Look up some 24V 3A transformers. If yours is similar in size / weight, it might be capable. If it is significantly smaller, no way. Bob
  5. BobK

    Creating an additional 'live' conductor with no reference

    You can create a different potential by connecting a battery to the conductor, the other end of the battery will have the potential of the live wire + or - the battery voltage. However, I don't think this is what you meant. If you want to draw power from the single conductor you cannot do...
  6. BobK

    Making new AC DC transformer for La Z Boy chair

    Yes, that would not be possible without 2 transformers (or 2 windings on one transformer). Edit: Replied too quickly. You could have a common ground if a half-wave rectifier is used for the DC, but not with a bridge, which is better and more common. Bob
  7. BobK

    What component does this symbol represent?

    Could be a constant current source, though normally, it is an arrow in a circle without the leads being connected to the arrow. Bob
  8. BobK

    Prevent Transistor Leakage

    Try measuring the leakage on your switching circuit. I measured a PN2222 with 30V from C to E and the base grounded through 100K. My meter reads 0.0 uA It you are getting leakage much higher than that, show us your circuit. Bob
  9. BobK

    Letting current flow only for an amount of time ?

    Sorry about that, I somehow missed all the posts after my last request for clarification. I hate it when people do that! Bob
  10. BobK

    Letting current flow only for an amount of time ?

    That depends on how you read the OP. I read is as there is a pump (with it's own motor) and the drill motor is used to "rotate the pump to get the water throwed [sic] in a specific direction" (OP's wording), But I can see your reading as well, where the pump is already pointed in the right...
  11. BobK

    oscillator help

    The two capacitors are across the inductor with the battery in series. Bob
  12. BobK

    Letting current flow only for an amount of time ?

    If you are trying to rotate a motor to a specific angle by timing the power to it, it is not going to work very well. You need angular feedback to do this correctly. Bob
  13. BobK

    Bucking voltages

    Where is it used? In each of the 100 or so cellphone / tablet / computer / whatever chargers that litter your home (if you are like me.) Bob
  14. BobK

    Rotating Solar Panel Mount/Limit Switches

    Hmm. The ones around here all seem to be fixed. Bob
  15. BobK

    Rotating Solar Panel Mount/Limit Switches

    You are wasting your time and money. A perfect 2-axis tracker only provides about 30% more energy than an optimally aligned fixed one. So using 30% larger fixed panels will produce the same energy at lower cost and higher reliability. Look around. How many commercial solar farms do you see...
  16. BobK

    Help designing a circuit to flip polarity to LEDS

    The simple solution is just to power the string with AC. Edited: 24V would be ideal and transformers are readily available. Bob
  17. BobK

    Splitting voltage

    What is the resolution of the ADC? If it is 12 bits, you would have to have very precise electronics to do the splitting and make it come out higher. And at most, you are getting 1 more bit of resolution. Simply taking more samples and averaging them will also increase the resolution. I...
  18. BobK

    Splitting voltage

    I do not understand your examples at all. How would you reconstruct the actual voltage from the split voltages? It does not look like any simple relation would do this. If all you want to do is read a voltage of up to 14.5V with a 5V ADC, simply use a voltage divider that will reduce the max...
  19. BobK

    Exactly how evil are Capacitors?

    They are only as dangerous as the voltage they charged to. Under 30V, not dangerous at all. Bob
  20. BobK

    Amps, amp-hours, and power

    If you have a battery that is rated at 60AH and it can put out 4800W for 12.5H, we can calculate the voltage of the battery as follows: 4800W x 12.5 hours = 60000WH 60000WH / 60AH = 1000V That is one hell of a battery! Bob
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