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  1. Y

    Project: Motor And Car Battery

    I 'm curious and would like to folow your project. I work with some what large storage batterrries (I have a bank of (65) 2.0v cells rateed at 950 Ahrs. Hydrogen is a concern and I have hyrogen monitors connected to an exhaust fan for safety. Most iof the hydrogen generarted is when...
  2. Y

    Metal Halide Starting Circuit

    Maybe the low resistance of the ionzed gas dampens the pulse. I was thinking the capacitor inductor cobination is resonating (Hi Z) creating the HV pulse, and the ionized gas ( Lo Z), lowers the Q (dampens) extiquishing the pulse. (Just a guess).
  3. Y

    Metal Halide Starting Circuit

    No, this fixture does not have a separate starter. There is only the two winding Xfmr/balast , capacitor, and bulb, all in series as indicated on the schematic printed on the core. Other fixtures I've worked on have the said starter, usually an encapsulated block with three...
  4. Y

    Metal Halide Starting Circuit

    Holophane PETL400MH48 FIXTURE using a 400W M59 base, Metal halide bulb. Does the capcitor and inductor keep making a HV pulse until the gas ionizes? What stops the pulsing? In this current fixture the capacitor opened up, but I replaced the Xfmr/Inducuctor combination as well, as...
  5. Y

    Looking for instruction: Control Networks

    I'm a dinosaur in the electrical field working with power and relays. I would like to learn about PLC's and industrial control networks using:Modbus, Profibus,Ethernet etc. Are there any good texts or correspondence courses available where I can lean the basic from ground up?
  6. Y

    Metal Halide Starting Circuit

    Interesting reply John, but no, this ballast/transformer is from a working light fixture. There is no dc circcuit. I was just looking for an explanantion how the series capacitor, inductor , bulb circuit creates the HV pulse required for ionization.
  7. Y

    Metal Halide Starting Circuit

    I was looking at the cicuit diagram for a Metal halide Lamp fixture and curious how it works. I see a step down auto tansformer with its tapped winding coneected in series with a 24ufd capaitor, then another winding (inductor), and then the lamp itself with the series return...
  8. Y

    Parallel resonance on oscilloscope

    It's Mr.Faraday to you!
  9. Y

    why are these transistors getting so hot?!

    The (6)transistors you show appear to be power supply regulators for the associated circuitry. Check the voltages on each zener cathode and compre to the voltage at the emmiter of each transistor, they should be close to same. If they are , the regulators are working, but may be overloaded...
  10. Y

    Computer Switching Power supply

    I didn't want to leave this hanging : I gave up. I replaced all the electrolytics and it no longer works in any fashion. I believe I have a solder bridge somewhere on the board. With out a schematic it seems hopeless. Theres a lot of surface mount chips on the foil side. I'm shelving...
  11. Y

    Computer Switching Power supply

    Unless these capacitors were labeled wrong. I would think 1000ufd would be typical. Most were in the output side (load side), but not all. I don't have a schematic. It's a 24VDC input, and then the typical ATX supply voltages on the output. 200Watt supply. The ESR is 10X what...
  12. Y

    Computer Switching Power supply

    No, measured 100 ufd and High ESR (5 ohms). Definitely all bad. I checked a new 1000ufd and got good results.with 1,8 ESR.
  13. Y

    Computer Switching Power supply

    Well, I didn't scope yet, but did one better. I removed every capacitor (15 pcs), and checked leakage, value, and ESR with my Sencore LC-101 Analyzer. I found (8 pcs) of 1000ufd @16 to have no leakage, value of 100ufd, and ESR of 5 ohms (almost 10 times higher than spec). I want to...
  14. Y

    Computer Switching Power supply

    I'll get the scope fired up this weekend. There are only 8 or 10 electrolytics, Ill check them all.
  15. Y

    70.7V line transformer

    If I understand: Suppose it is a 100 watt tube amplifier. It's output transformer matches the Push pull output to 70,7 line. (10000 : 50 ohms Z for 100 watt load). Now if I want to power a 10 Watt 8 ohm speaker a 500 : 8 ohm matching transformer would be needed. Z= 70.7 sq'd / 10 watts =...
  16. Y

    70.7V line transformer

    The Crown link was helpful. I've never seen circuitry for a tube amplifier using 70.7 line. I can see it would be fairly easy to build a solid state output that has realitvely low output impedance. I'm thinking this could be accomplished without a tranformer on the amplifier itself...
  17. Y

    Computer Switching Power supply

    Computer smps Actually, my computer runs on 24 VDC , and the supply is a dc to dc converter. It has been in operation 24/7 , 8 years. I think its just tired. It still has useful life. I've replaced the supply and have it working. I'm trying to troubleshoot the old tired supply...
  18. Y

    Computer Switching Power supply

    I' have a switching power supply, and it works intermitently. I'm thinking a component is out of tolerance because it works some of the time. I measure the Vs (start up) and it measures only 4.2 Volts ( when its working , and when its not). I'm thinking this is the culprit. Any ideas...
  19. Y

    70.7V line transformer

    Ok, I understand how to match a 8 ohm speaker to an output tube. I match the plate resistance to the primary. I can calculate turns ratio and thus calculate impedance. What I can't grasp is how do you match a 70.7 volt line to speaker transformer. It must have a primary impedance. How...
  20. Y

    LED Drivers?

    LED circuitry I was thinking: with a battery, supply the current would decrease as the battery discharged so why not just a series limiting resistor. Added circuitry would just discharge the battery faster? If voltage decreases, the current has to decrease as well. What am I...
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