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  1. (*steve*)

    Question about A/C electricity

    Both AC and DC can be carried on 2 conductors. Your 3 wire motor uses a pattern of three AC waveforms with a phase relationship to each other to make it work (I'm assuming here, because you don't give any information). When you soon it, you get a combination of three AC waveforms, one on each...
  2. (*steve*)

    Regular epoxy adhesives for heat sink?

    Golf club epoxies are probably not the sort of epoxy intended to be exposed to continuous high temperatures. I would find a brand name adhesive that has an available datasheet. For example, for loctite products, see here. As an example, loctite 4090 has this datasheet. Compare that with...
  3. (*steve*)

    Transistor Tyristor x-FET

    I have a job that requires a truck with a gate. My house has a fence with a gate in it. Can I use my fence as a replacement for a truck?
  4. (*steve*)

    Regular epoxy adhesives for heat sink?

    Somewhere I pointed to an article where heatsink compound was compared to various alternatives. Some of these alternatives (if I remember correctly) were toothpaste, butter, and chocolate. In a not very surprising result, they found that almost anything worked. The reason is that the primary...
  5. (*steve*)

    What type of battery is good for emergency power for blackouts?

    A fit person can produce 50 to 150 watts for an hour. That is energy expended, not energy captured, so the power available for charging batteries etc would be lower. Then you need to think about charging efficiency of the cells, and the efficiency of the charger. However, the fact that 1...
  6. (*steve*)

    Help to identify and source fried component from Wireless Charger PCB

    It's good to hear you have a reflow station and are experienced at surface mount soldering. Unfortunately your images are too low a resolution for me to tell anything. If I click on them in taken to a very spammy this party site. Please upload your images here. Also, please read the...
  7. (*steve*)

    Gas diffusion - a question or two

    The argon will be actively pumped out of the window. As the temperature cycles, the pressure inside will raise and lower. Your seals are unlikely to be airtight. Thus the loss of argon will be much faster than if it was by diffusion alone. Would some quantity of dessicant in the bottom of...
  8. (*steve*)

    What type of battery is good for emergency power for blackouts?

    Beware that most power banks rate their capacity as the mAh rating of their battery. A 20000 mAh device has a 3.7V 20000 mAh battery in it (if you're lucky). Assuming an 85% efficient boost converter that translates into 12600 mAh at the output. A safe assumption is that you get half of...
  9. (*steve*)

    Diode and transistor failure

    it is possible that the diode failed short circuit first and then the transistor failed because it was switching the entire current available from the power source.
  10. (*steve*)

    Current Limiting

    The way a constant current device reacts to a sudden attempt to draw more current (than the limit) is to reduce the voltage applied to the load. Your LM317 circuit sounds like it is doing exactly that.
  11. (*steve*)

    LED string

    Let me guess, the last LED is red and the others aren't? You should have a separate resistor for each LED. Ok the basis of what you have now, four 1.2kΩ resistors should do the trick.
  12. (*steve*)

    LED string

    What value resistors do you have in series with the LEDs?
  13. (*steve*)

    What type of battery is good for emergency power for blackouts?

    Yes, there are cases when the mechanical hydrocarbon-oxygen primary fuel cell is the easiest and most reliable option.
  14. (*steve*)

    What type of battery is good for emergency power for blackouts?

    The best battery for this type of situation is likely to be a tank of diesel. You need to make sure nothing affects the diesel whilst in storage.
  15. (*steve*)

    Adjusting voltage

    In order to answer that question, we need to know the following: The current output voltage, The desired output voltage range, The nature of the load you wish to drive (specifically it's impedance), The frequency range, Any other specific criteria (like distortion)
  16. (*steve*)

    How to turn Smoke alarm into Ultrasonic Dog Repeller

    Was the dog planted previously? My gardening experience tells me that you should probably use a bigger pot when you replant it. Perhaps you mean repellant? Do you know what repels dogs? I don't. When one of our smoke alarms goes off it annoys the heck out of me, but the dogs just ignore it.
  17. (*steve*)

    Replace 6 AA with 9v 1~2 amp DC adapter

    The adapter has a rated input voltage from 100-240V (or similar). As such I bet it's pretty dead on the voltage.
  18. (*steve*)

    Verilog code for 256 bit Brent Kung adder

    In that case it belongs in the homework section and you need to read the rules for this area (i.e. you're not going to get an answer on a platter.
  19. (*steve*)

    Replace 6 AA with 9v 1~2 amp DC adapter

    It is possible that the original device uses the middle of the batteries to generate a +/-4.5V supply. Without that connection, bad things may have happened. Can you show us what smoked?
  20. (*steve*)

    LED ON / OFF by Magnet

    Or look for a small hall effect device. Those with a digital output my at be able to drive a led.
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