Activity for Andy aka
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #277301 |
Your circuit WILL NOT work with the load negative connected to ground. (more) |
— | over 3 years ago |
| Comment | Post #277301 |
Your circuit is incorrect on the output. The load needs to connect between the source and a positive supply voltage not ground. Your hyperlink doesn't work and you haven't shown the value of the MOSFET source resistor. You haven't mentioned what op-amp supply decoupling you have used either. Assuming... (more) |
— | over 3 years ago |
| Edit | Post #277276 |
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— | over 3 years ago |
| Edit | Post #277276 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Complementary transistor pairs - what is the point ? To understand why complementary pairs are used, it's probably a good idea to think about the limitations of the NPN emitter-follower circuit: - Image alt text It's a good circuit for delivering modest powers to a load but its main disadvantage is that it dissipates excessive power in the emitte... (more) |
— | over 3 years ago |
| Comment | Post #277051 |
@coquelicot there is capacitive coupling between all the wires in the bundle that make up the cable. L2 is not ideally split halfway of course because that would make the L2 voltage become 60 volts. (more) |
— | almost 4 years ago |
| Edit | Post #277051 |
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— | almost 4 years ago |
| Edit | Post #277051 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: How could a damaged wire in split-phase power delivery create these voltages? > When the outage occurred, I observed the following - The L1/G voltage difference was 120V (good). - The G/L2 voltage difference was 90V (bad). - The L1/L2 voltage difference was 30V (very bad!). If the L2 wire was broken then, due to capacitive coupling between L1 and L2 (and the use of... (more) |
— | almost 4 years ago |
| Comment | Post #276952 |
..... I spent a whole year on one job trying to find an answer to this specific type of problem where a device had allegedly passed an impulse test but there were no records kept. In the end I concluded that someone had added TVS diodes to a design after testing had been done, didn't do their homewor... (more) |
— | almost 4 years ago |
| Comment | Post #276952 |
Can you address my questions above as a comment because I don't want to have to trawl through the whole question trying to work out things. What I can say is this: without knowing what specific testing destroyed the devices is not going to help..... (more) |
— | almost 4 years ago |
| Comment | Post #276952 |
What testing was conducted that destroyed the failed devices? Are you looking for reasons behind these failures? Can you be specific about what advice you are seeking? What insulation have the load cell bridges got from the grounded rail? What specific tests were conducted? Was it ESD or indirect lig... (more) |
— | almost 4 years ago |
| Edit | Post #276319 |
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— | almost 4 years ago |
| Comment | Post #276809 |
@Olin - not sure I was. I can't remember proposing a new site. Maybe it was something I said once? Hold fire on me being a mod. (more) |
— | almost 4 years ago |
| Comment | Post #276809 |
Well, it's risen back a bit from 316 to 321 but it still hasn't returned to circa 352 so, I'd say that it isn't fixed. I agree with Olin, about mods getting the right tools to do the job. As a plain ordinary user, there isn't enough information that I can find that tells me where up-votes or down-vo... (more) |
— | almost 4 years ago |
| Edit | Post #276809 | Initial revision | — | almost 4 years ago |
| Question | — |
Strange things happening Why has my reputation dropped significantly over-night from around 352 to 316? Why are there a bunch of new people listed with decent reputations who seem to have appeared from nowhere? (more) |
— | almost 4 years ago |
| Comment | Post #276662 |
Safe after two faults is the reason. They all, individually, have to be able to survive the input current that might pass through the fuse indefinitely. (more) |
— | almost 4 years ago |
| Edit | Post #276662 |
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— | almost 4 years ago |
| Comment | Post #276662 |
@Hawk2000 The barrier doesn't care about energy transferred to it; rather it's the other way round. The barrier is situated in a less onerous gas environment so clearly, it is protecting down stream (into the more onerous gas environment) from excessive energy. The barrier "buffers" anything on its i... (more) |
— | almost 4 years ago |
| Edit | Post #276662 |
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— | almost 4 years ago |
| Edit | Post #276662 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: How do I calculate and manipulate the inductance and capacitance of outputs to a connector on a PCB? > How do I calculate the inductance and capacitance out from the barrier to make sure it is less than the sensor values? The output capacitance and inductance from your zener barrier is irrelevant - you design the barrier components (fuse, zeners and output resistor) to limit the short circuit ... (more) |
— | almost 4 years ago |
| Edit | Post #276438 |
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— | almost 4 years ago |
| Edit | Post #276438 |
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— | almost 4 years ago |
| Edit | Post #276438 |
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| Edit | Post #276349 |
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— | almost 4 years ago |
| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276436 |
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| Edit | Post #276436 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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| Edit | Post #276438 |
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— | almost 4 years ago |
| Edit | Post #276438 |
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— | almost 4 years ago |
| Edit | Post #276438 | Initial revision | — | almost 4 years ago |
| Answer | — |
A: How do I design a flyback converter? What are the basics I should know? Equivalent Circuit, 1:1 transformer Start by simplifying the circuit and change the transformer to a single inductor. This simplification ignores the benefits of isolation but, flyback converter theory is about transferring energy and not fundamentally about isolation: - Image alt text We al... (more) |
— | almost 4 years ago |
| Edit | Post #276436 | Initial revision | — | almost 4 years ago |
| Question | — |
How do I design a flyback converter? What are the basics I should know? I need to design a simple flyback converter like this: - Image alt text I want to control duty cycle from another circuit such as an MCU but, I'm unsure how to proceed. My requirements are: - - Input voltage `125 volts` - Output voltage `500 volts` - Load resistance is `10 kohm` - Tra... (more) |
— | almost 4 years ago |
| Edit | Post #276349 |
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— | almost 4 years ago |
| Edit | Post #276348 |
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— | almost 4 years ago |
| Edit | Post #276403 |
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— | almost 4 years ago |