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  1. alfa88

    Old Zener Diode

    Whew! you had me doubting myself. Nah, I was just drawing down the way I had my test setup slapped together. The jumper was so I could connect and remove zeners easier. Maybe I'll cleanup the drawing to be more ascetic. Magnetec, In lieu of an adjustable power supply you could maybe use a...
  2. alfa88

    Old Zener Diode

    Whaaa?! I simply have the resistor on the other side of the diode. It's still getting current limited. The measurement is still across the junction of the resistor and diode to the other side of the diode.
  3. alfa88

    Old Zener Diode

    Jumper cable
  4. alfa88

    Old Zener Diode

    Here's my pictorial to add to Davenn's explanation. I just sorted out a bunch of zeners last week this way. Remember to label the diode if it's going into the parts bin.
  5. alfa88

    Determining Rectifier Size

    Darwin Awards was exactly what I was thinking. Excuse my poor math but I believe the original poster has moved on one way or the other. Bzzzzdt!
  6. alfa88

    Determining Rectifier Size

    Big rectifier = good, smaller rectifier = not as good, even smaller rectifier = wrong. More windings = less load. Using mains power = bad idea Using car battery = safer idea(plus you could dispense with the rectifier) I don't know of anyone that enjoys coil winding. At least I have the blue...
  7. alfa88

    Determining Rectifier Size

    He said he was using a rectifier. That basically cuts the voltage in half.
  8. alfa88

    Determining Rectifier Size

    Might I suggest you use a battery and scale things down for your experiment. As you have it now. 120V, rectified = 60V 26 guage@1500ft. = 61.215 Ohms 60V/61.215Ohms=0.98A (current capacity of 26 guage wire is 2.2A) That's alot of wire! But you wont trip a breaker. By the way you want to use...
  9. alfa88

    New Power Supply

    Electronic design after cocktail hour is not a good idea. I would have caught that eventually. My bad Davenn. R2 is a bleeder resistor. It wont be connected when the power is on. It does seem a little low in value though. I might change that to 1K.
  10. alfa88

    New Power Supply

    My latest iteration. I did away with the current regulation for now, took capacitor advice and added transistor labels. I selected GPs for Q2 and Q3. If memory serves correct Q1 and Q3 are the ones that handle the current. I'm not too happy with the cooling fan/ pilot light arrangement. I'd...
  11. alfa88

    New Power Supply

    I found this at a robotics forum. It's around 6 years old and Zamboniman60 never related whether he got it working or not. For sure I'll be breadboarding this in stages. I've got plenty of 50V caps.
  12. alfa88

    New Power Supply

    I'm aiming for 4 Amps. Transformers start getting pretty pricey beyond that. The circuit was supposed to be designed for 5 so a little tweaking in the current limiting area will be in order.
  13. alfa88

    New Power Supply

    My power supply went poof. Turns out the transformer was poorly assembled and the outer windings were able to short against the core. Anyhow I am considering more power. I came across this design. Credits go to Zamboniman60. Feedback anyone? I believe the positive is using a Darlington pair as a...
  14. alfa88

    Wall Wart Question

    Thanks Steve. C11P is indeed a zener. I ran a check and had a WTH moment then I remembered I was dealing with a 12V wall wart not 5V. C11P is 11V. Rather than producing a separate board the Chinese company that made this simply exchanged parts to suit the higher voltage. The silkscreen on the...
  15. alfa88

    Wall Wart Question

    I'm reverse engineering a cheap wall wart and I think I have the circuit pretty well traced, One problem I have is some of the diodes have odd numbers D5, D6 and unlabeled 'C11PH' . Another question I have is where is the regulation coming from?
  16. alfa88

    identify the ohmage of this slide potentiometer..

    Is the function of VR10 for output volume? In that case I would think that should be audio taper (logarithmic) rather than linear.
  17. alfa88

    Subwoofer Amplifier

    Here's the numbers I come up with. 50N06 - NTE2395, 12c20 - NTE5910 or 11, A1941 - NTE36
  18. alfa88

    Why does my camera go flat so fast?

    My camera eats batteries like crazy too. The zoom and the screen are big power hogs. Try using lithium cells [not to be confused with lithium-ion(rechargeable)cells] They claim to last 7X longer. A lot more expensive but the longevity might outweigh the cost. I hear tell a newer version is...
  19. alfa88

    Just throwing out an idea......

    It just occurred to me that Kirlian photography might be in this realm. We're getting pretty close to Ghost Buster tech here.
  20. alfa88

    Unknown LED symbol

    I have never seen it drawn like that but I'll throw out a guess that that oblique triangle on top is saying it's used for a turn indicator.. Only a guess.
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