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  1. Delta Prime

    LM394 National Semiconductor 'supermatch' NPN pair

    That seems to be the consensus. Even if you match up a pair of discretes on a curve tracer, the thermal differences will still cause gain drift. You will need to either use a monolithic solution or maybe try to enclose the pair with silicon thermal grease and a copper clip to attach them face to...
  2. Delta Prime

    1000VA UPS

    See what a wonderful community can do for you when everyone comes together. enjoy! I know I did. My technique is called self-deprecation now everybody feels good about themselves but they don't know why? Two steps ahead people. The in-depth information provided; resources...
  3. Delta Prime

    1000VA UPS

    I noticed that capacitor has a class X2 designation, obviously it failed, could be for many reasons if there was a surge on the electrical service mains,you're quality of the grid voltage, comes into question? Therefore I would recommend a capacitor with a class Y1 which are impulse tested to...
  4. Delta Prime

    1000VA UPS

    And you have to watch out on schematic symbols of a MOV Metal Oxide Varistor The MOV in the schematic below looks surprisingly similar to the thermistor in the component chart.thermistors are normally placed in series to The circuit it is protecting. While the MOV is obviously placed in...
  5. Delta Prime

    1000VA UPS

    Use the schematic as a guide we need to verify where C5 and R3 are connected to or terminate. Along with CN5. You are more than likely have to make your own schematic. And use the reference designators for example capacitor,C5 and resistor, R3 and relays RY1, RY2, normally open, (NO) normally...
  6. Delta Prime

    1000VA UPS

    Respectfully, I am not accusing you of subterfuge. The visual information you have provided the photos and schematic are an asset. The link along with you're updated photos will help tremendously. I will conduct research for that particular unit and hopefully more information can be obtained...
  7. Delta Prime

    Comedy Thread

    Mary Tyler Moore is a guest on the David Letterman Show. Letterman asked her what was the funniest joke she ever heard. She answered: “One day a man went to go see a big shot talent agent to see if he would consider representing him. The agent said “well, I’ve got to see want kind of talent you...
  8. Delta Prime

    1000VA UPS

    Common mistakes people make When trying to repair electronic equipment is replacing components that do not supply sufficient current to the load or allow excessive current to the load, inserting different value fuses other than the ones that circuit board is originally designed for is one...
  9. Delta Prime

    And now something weird

    Medieval philosophers debated how many angels could dance on the head of a pin; modern scientists are getting close to sticking a particle accelerator on one instead. Ok, this particle accelerator doesn't fit on a one-cent piece, but it could manage on a larger one. Image Credit: FAU/Laser...
  10. Delta Prime

    1000VA UPS

    Would you have any documentation to go with that schematic? How did you come across that schematic? That little resistor you mentioned Is R3 . We need to find the component values! Capacitor C5 is destroyed. Now, the two two pin connector CN5 has a fuse (F1). I don't see it on the board...
  11. Delta Prime

    1000VA UPS

    Then I'll have to take your word for it.Because the fuses keep changing color on me and values from 30 to 40 amps green to Red respectively. Could you please provide a photo of the four output mosfets. Do you mean the 47 ohm resistor that looks like it has been cleaved or sliced with an exacto...
  12. Delta Prime

    Interesting Video On Electricity

    I find this entire subject to be a real Bohr! ;) Michelson and Morley failure was a success in my book only because it eliminated an assumption. It is the process of science. I believe "Gravitational Lensing" took care of that one. Bohr and Einstein famously clashed over quantum mechanics...
  13. Delta Prime

    Thought for the day .....

    Even moderation; should not be practiced...to excess! ;)
  14. Delta Prime

    And now something weird

    Scientists believe a lack of understanding of ocean life and its distribution is one of the biggest barriers to restoring marine biodiversity damaged by overfishing, pollution and climate change. https://phys.org/news/2023-04-snailfish-impossible-fish-broke-deep.html
  15. Delta Prime

    King Kong massage chair

    @chanellsworth You should probably delete all of that information.
  16. Delta Prime

    ENERGY MEASURE WITH AN OSILOSCOPE

    Kudos to you! You're very observant! Although the link submitted below indicates current spikes the principle is the same! A very elegant solution has been given by a fellow member of this site...
  17. Delta Prime

    Nixie Tube Driver Question (w/ Schematic)

    One could be rebellious and kind at the same time! I just don't understand why? anyone, would go out of their way; to be anything else. As a complement to post number7 I submit to you an additional resource,which would compensate for the negative temperature coefficient. In using two NPN bjt's...
  18. Delta Prime

    Comedy Thread

  19. Delta Prime

    1000VA UPS

    My friend what have you done! it's okay you can tell us everything;no one else will know! You need to disclose what you're doing cuz this is very dangerous! Contrary to popular belief, you just cannot change the value of the fuses willy-nilly! I'm not trying to beat you up. I'm trying to...
  20. Delta Prime

    DC Motor Control Using IR2104 Driver

    Welcome to Maker Pro. :) Could you please provide the manufacturer data sheet of your motor? Could you please provide a link to the source of this schematic?Thank You. Here's an additional resource. How to choose the bootstrap components. The equation can be transposed; examples are given...
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