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  1. alfa88

    High-voltage failsafe?

    An example might be a 'bleeder resistor ' on the large capacitors of a power supply, say, 10k. When I worked for an electrified commuter rail system and the rail was powered down breakers had to be racked out, rail voltage tested and then shorted to ground. 1000V@100Amps can leave quite a mark.
  2. alfa88

    Electronics Mortuary

    I should have known. It did this from day 1. Now after 2 years it will blink off just as I attempt to make a measurement. With a fresh battery. This Chinese knock off is giving me a Devil of a time.:D
  3. alfa88

    Electronics Mortuary

    I think it's time for a new multimeter. This meter displays these numbers when it first starts up.:eek:
  4. alfa88

    Demodulation

    It is a transformer of sorts. It couples the signal from the antenna to a resonant tank circuit. The value of L1? Who knows? You could find one in a discarded AM radio in the form of a loopstick antenna; coils wound on a ferrite rod. Finding the capacitor value will take experimenting with alot...
  5. alfa88

    What component is this? (relay content)

    Cool Pic! As current increases the curved bi - metal plate expands, In a over current condition the curve straightens out to the extent that the welded 'point' on the end breaks contact with the mating contact. In most cases when when the over current event subsides the metal strip assumes...
  6. alfa88

    Could you help on interpreting part of a circuit?

    1uF, 50V Non polarized electrolytic perhaps?
  7. alfa88

    Help with wifi routing

    Google CANTENNA
  8. alfa88

    What component is this? (relay content)

    Davenn wins.
  9. alfa88

    Demodulation

    For the life of me I can't recall where I found this transmitter schematic. I didn't have a variable cap. so I used a fixed value I had sitting around. The range wasn't all that good but then again I slapped it together with no regard to lead length, noise, etc.
  10. alfa88

    computer not booting

    Remove all peripherals, install the ram in the original configuration, reset BIOS.
  11. alfa88

    How to test a mosfet?

    Do a Google search. That's what I did.
  12. alfa88

    Why did my PA fuse blow?

    A couple questions: What is the make and model of the amp?, I saw a schematic of a power supply, do you have a schematic of the amp? From the pics it looks like the amp has 4 different power supplies and I figure the 2 fat diodes are feeding the output transistors. I don't think that's your...
  13. alfa88

    Velleman K8048

    Pardon my naiveté. Coming from a basically 1 chip, Parallax experience. I realized there's code for different chips... Duh! l shall return with better questions.
  14. alfa88

    Velleman K8048

    Okay so I got Velleman K8048 the problem is I misplaced the disc that came with the kit. The Velleman website has the driver and assembly directions but that's about it. I'm wondering if there's some tutorial and sample code on the disc. I have no idea where to go from here. Anybody have...
  15. alfa88

    Schematic for a Tenma Signal Tracer/Injector #72-540

    It's been a while. I believe I Emailed them. I'll attach a schematic of the function generator section . Maybe there's some similarities.
  16. alfa88

    Schematic for a Tenma Signal Tracer/Injector #72-540

    You may want to contact Tenma. They were good enough to send me a pdf of one of their scopes.
  17. alfa88

    why are these transistors getting so hot?!

    That's good, so you're not overdriving the amp. If the receiver has a fan insure it's working. I suppose the operative phrase would be, "If it aint broke don't fix it"
  18. alfa88

    why are these transistors getting so hot?!

    What is the impedance of your speakers?
  19. alfa88

    solar cell fail

    It beats Aunt Bea's pickles. There's too many uber brainiacs beating me to the answers but I just got a pic programmer so I'll have plenty o' questions soon. I once contemplated a saltwater battery to power our condo but the cost of replacing the zinc anodes would be prohibitive as well as...
  20. alfa88

    solar cell fail

    It sounds like a saltwater cell(battery) to me. Yeah, redox.
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