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  1. F

    Measuring Current via voltage measurement

    The problem stated a requirement to "add" a resistor and measure the voltage across it. Also the Op asked "what would be the optimum value of the resistor".. I think I provided an appropriate answer that stayed in context with the Op's post.
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    Is there a 12VDC power regulator / timer?

    I'm not sure how much "battery" is saved by intermittent charging vs. constant charging, but it might be significant. Anyway, here's a device that might work...
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    Measuring Current via voltage measurement

    Hunter64, maybe I missed something, but it sounds like this is a working circuit and the goal is to measure the collector current. Therefore, adding the lowest possible resistor would be desirable to have the minimum impact to the collector current. Frank
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    Chronograph USB to serial question

    If your phone has an app that's designed to use that exact cable and also your chronograph then it should work. Of course, you probably wouldn't be asking the question if that was the situation. Without more information we cannot answer your question, but my guess is that it will not work. Frank
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    Measuring Current via voltage measurement

    Many times the optimal resistor is one that has the least affect on circuit operation. So without extensive analysis, I would choose the lowest value possible that still produces a voltage large enough to be measured by your voltmeter. Of course, if you have some idea of what the circuit...
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    Hot cellphone maybe bad wifi chip

    I doubt that you can fix the problem by changing a chip. I'm not familiar with that phone, but see if it has a power saving mode that might help. Frank
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    Use a Computer to replace Circuit Boards

    Making a DIY washing machine control board is a tall order. Usually you can buy used boards on ebay for a reasonable price. Frank
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    Looking for some kind of lamp relay/trigger

    You might want to look at automotive type 12v cigarette lighter strobe lights sometimes used for emergencies. You will need to determine the 12v current capacity of your clock. My guess is that capacity will be less than 1 amp (12 watts) so you will need to find a strobe light rated at less...
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    Audio limiter to quiet loud radio commercials

    Yes, I know that my passive operation is fairly unusual and can be challenging to get low distortion. Thanks for the tip on attaching a picture. Frank
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    Audio limiter to quiet loud radio commercials

    Yes, that is the circuit that I was talking about. That's odd, when I click the link using Chrome it goes to the top of the page and I see my doubler circuit. When I use IE it still goes to the top of the page, but my doubler circuit does not load, just a spinning circle where my doubler should...
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    Audio limiter to quiet loud radio commercials

    Bob, I think you are looking at the wrong doubler circuit in my link...The circuit I am using is the first circuit at the top of the page. It called a voltage multiplier, but it's basically a doubler.....there's no transformer in the circuit that I am talking about. Furthermore, the doubler...
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    Audio limiter to quiet loud radio commercials

    Bob, Here's the doubler circuit I'm using. It doubles with respect to ground. Edit: Not sure why my above image doesn't work. The first doubler in the link below is what I am using. https://www.electronics-tutorials.ws/blog/voltage-multiplier-circuit.html
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    Audio limiter to quiet loud radio commercials

    Bob, you are right again, I could have sworn I got a higher voltage with the bridge, but I went back and tried it and It doesn't. However, when I ground the positive side of the bridge, like I was doing previously, the voltage almost doubles. That explains why I thought the bridge gave me a...
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    Audio limiter to quiet loud radio commercials

    Oops, of course you are correct. Grounding one of the bridge outputs shorts across one of the diodes, etc., as you said...Somehow it didn't seem to cause any problem, at-least I didn't see any problem yet. I'm so used to working with transformer connected bridges in power supplies, where you can...
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    Audio limiter to quiet loud radio commercials

    Okay, the source follower circuit is working very well. I had to connect the output of my 4-diode rectifier between ground and the gate, rather than between the source and the gate. When connected between the source and the gate somehow some 1/2 wave ripple from the rectifier was getting...
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    Audio limiter to quiet loud radio commercials

    Prior to seeing your fix, I shorted out R1 and inserted a 10k resistor from the source to ground. And then took the output from the source of the JFET. I think that's called a source follower circuit. I'm applying the rectified control voltage between the source (+) and the gate (-). I suspect...
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    Audio limiter to quiet loud radio commercials

    Yes, I just saw that in my testing. I don't see an easy fix. Frank
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    Audio limiter to quiet loud radio commercials

    Okay, I'll give it a try. Good point about the 50uf cap, I realized that a few days ago and added a drain resistor. Frank
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    Audio limiter to quiet loud radio commercials

    Thanks, good idea to use a potentiometer to fine tune things. Frank
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    Audio limiter to quiet loud radio commercials

    Thanks, I think I got it... I'm using a 4-schottky-diode bridge because an opamp needs a power supply that I am trying to avoid. Anyway I think your answer to my question is "yes" (plus to source, minus to R4) as that would negatively bias the JFET as you stated. However, you also stated "the...
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