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  1. (*steve*)

    Really Need Advice Making Micro Wind Farm

    No. The power you can get depends on the wind shouted and the swept area of the blades. So, for the same wind speed, the diameter of the blades must be extended by 41% to double the power.
  2. (*steve*)

    Can it damage IC if connecting two speaker in parallel in output?

    8 ohms in parallel with 4 ohms is 2.67 ohms. That's way less than 8 ohms. If you are operating this at a voltage higher than +/- 17 volts then you risk exceeding the maximum current through the device. I wonder if your 8 ohm speaker is damaged.
  3. (*steve*)

    2N3055's and heat

    On that subject, there are some circuits on the net which are tracking preregulators for lm317s. The employ a transistor to drop the input voltage to (say) 10V above the output. This allows you to short the output (or for the device to go into current limiting or thermal shutdown) without...
  4. (*steve*)

    2N3055's and heat

    In this case he I'd taking about current sharing, and the same mechanism which causes thermal runaway causes instability in the amount of current shared leading to one (or more) transistor handling more power than they would if the current was balanced. The emitter resistor adds negative...
  5. (*steve*)

    Trouble understanding shunt resistance for short-circuit current measurement

    Whilst your idea for how to wire up an op-amp are kinda right, if it is done the way you suggest, the gain will be uncontrollably large. The inverting input needs to be involved with a feedback lop which sets the gain to be what you desire. Another issue is that the op-amp needs to allow the...
  6. (*steve*)

    Zener Diode - I feel terrible!

    I found one zener, but it was a stud mount 2N3327A or similar, and clearly not whar goes there. Do you have the original part? Perhaps it has useful markings?
  7. (*steve*)

    Designing my first basic circuit - But have a few Questions

    But as drawn, the circuit only requires 8/100ths of an amp.
  8. (*steve*)

    Buck convertors

    you typically have the emitter resistors drop about 0.1V to 0.5V at the full rated current of the supply. If full current was 10A and you were splitting it between 3 transistors, then each resistor would have 3.33A through it with a (say) 0.25V drop. So the resistance is 0.25/3.33 = 0.075 Ω...
  9. (*steve*)

    Help With Circuit

    1 to 100uA should be fine. Use a resistor which drops 1V at 100uA... 10k as your sense resistor. A logic level mosfet capable of a couple of hundred mA should have leakage way below 1uA
  10. (*steve*)

    Help With Circuit

    Since it is the same circuit, yes the same rules apply. The limitation on the maximum size of the sense resistor will be due to the input impedance of the op amp, noise, and leakage in the mosfet. The minimum value of the sense resistor is dependant on the current and power ratings of the...
  11. (*steve*)

    Greetings

    Hi Welcome to Electronics Point.
  12. (*steve*)

    Help With Circuit

    Unless your requirements have changed, use a p channel mosfet.
  13. (*steve*)

    Help With Circuit

    As suggested previously, read the other thread. He wanted a constant current source peering powering a load on the -5v rail.
  14. (*steve*)

    Wiring question (vague, I know...)

    No problems at all.
  15. (*steve*)

    Help With Circuit

    Look at the corrected one posted by audioguru
  16. (*steve*)

    Buck convertors

    You need to take into account the junction to case thermal resistance and the thermal resistance case to heat sink. This week probably not add a lot to the temperature rise, but it can be significant. Also, it's the addition of EMITTER resistors which are what is needed for transistors in...
  17. (*steve*)

    Programmable negative constant current source

    Note that the actual problem with my circuit is that the p channel mosfet is upside down, not of the wrong polarity. It should be a p channel with the source toward the to of the diagram. See here https://www.electronicspoint.com/threads/help-with-circuit.281274/#post-1713445
  18. (*steve*)

    Help With Circuit

    Thanks for the correction, by the way.
  19. (*steve*)

    Help With Circuit

    The original thread is here https://www.electronicspoint.com/threads/programmable-negative-constant-current-source.277347/ I did eventually realise I had drawn the mosfet incorrectly and then gave the wrong fix. I drew the mosfet upside down and compounded the problem by recommending an N...
  20. (*steve*)

    Help With Circuit

    Sorry, I was looking at your corrected version. I think I noted that the mosfet was shown backwards in the original thread. And here is yet another reason not to start new threads... I'll try to find the original thread with the full discussion.
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