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  1. Herschel Peeler

    Help needed on simple short circuit protection

    Starting rough draft. Design details depend on current levels that are normal and what you want to call normal. Too many parts?
  2. Herschel Peeler

    Help needed on simple short circuit protection

    At 3 Volts there isn't much room for a current limiter circuit. A fuse? Do you have a cost limit in mind? There are current sensor circuits and chips. If you had that turn off a MOSFET in series with the power line that would get the loss down. How much current is normal? At what point would you...
  3. Herschel Peeler

    Hello from Belgium

    Last time I looked at such things (years ago) lighting for seedlings was different that for mature plants. I guess that might depend on what you are growing. It went something like this: F1 spectrum, growth cycle Far Red (700 to 780 nm), 0.1% Red peak at 660 nm at 0.055 W/nm (600 to 725 nm)...
  4. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    If you were designing something with a coaxial connector and cable would you put ground on the outside?
  5. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    How would you build it? Would you put the hot side to the chassis? I have hundreds (literally) of wall warts. I don't think any have positive on the outside.
  6. Herschel Peeler

    Output resistance of equivalent op amp circuit

    Well RL is the input resistance of the next op amp; meg ohms??? Next to meaningless in the equation. Considering a real circuit ...
  7. Herschel Peeler

    Output resistance of equivalent op amp circuit

    Ro + RL || R22 makes sense if you just consider the output. Nut, as suggested, this is not the whole picture. Yes, with 0 V out the resistance is Ro || RL || R22. I can see that. But there is no output and no current. With no current out do we have a divide-by-zero problem in V/I? :-) With Ro...
  8. Herschel Peeler

    Output resistance of equivalent op amp circuit

    That does seem to be the question. No matter what the output voltage does the formula change? What is the actual difference in voltage at the output under either circumstances? How much does R22 change with, say, 1 V in? Sorry if this is covered in the other posts. I haven't read them all yet...
  9. Herschel Peeler

    Output resistance of equivalent op amp circuit

    Interesting. If the output voltage source is the output driver then then it makes sense that the answer is RO + RL||R22. All the output current goes through R Out, then is split between RL and R22. Assuming V In = 0 V.
  10. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    Not necessarily. Note the connection. The center terminal is negative. The outside connector is positive. it could be positive ground. Meter it from the terminals to earth ground.
  11. Herschel Peeler

    Question about operational amplifier circuit Dorf exercise 2.5?

    Yes, voltage follower. R1 is on the wrong side of R2 to be an amplifier. R1, as shown, is just the load.
  12. Herschel Peeler

    increasing voltage or current

    6 LEDs in parallel means 6 times the current.
  13. Herschel Peeler

    Electronics modules names and why there are so many manufacturers of the same thing

    Owners of Owners of patents can also license other manufacturers, allowing them to make the product.
  14. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    Interesting. LM2596 explains the big box but still regulated. "Simple switcher" and a 60 Hz transformer.
  15. Herschel Peeler

    Help with code.

    Ah, super! A great way to get started.
  16. Herschel Peeler

    Help with code.

    I have never seen it referred to as that. Thanks.
  17. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    Our experiences certainly differ.
  18. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    "+12 V DC, 100 mA to 1 Amp" says the voltage stays steady over a broad current range, suggesting a switching regulator. A part number would help confirm or deny this. I haven't seen many wall warts with a linear regulator inside.
  19. Herschel Peeler

    Reducing amps in a circuit without change in the voltage

    Non-switching types are just a transformer, rectifier and maybe a capacitor. 60 Hz transformers are relatively massive and cubical in dimension. Switching regulators change the line voltage to a high voltage DC, chop it up at a high frequency then it goes through a high frequency transformer...
  20. Herschel Peeler

    Output of the alternator

    You are correct, no magical gain in power. The HP rating is "minimum" not practical. Under heavier current load higher horsepower is required. Actual HP requirements would depend on so many different factors. It would be hard to put into the data sheet. Not dishonest, just misleading. It calls...
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