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  1. F

    Converter output

    Lee47, Maybe I missed something, but I don't understand the problem. If the USB charger is always connected to the battery that smooths out the converter if it is active via the transfer switch. If the transfer switch is on shore power the converter is out of the picture and the USB charger...
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    Capacitance Measuring Circuit - Can This Circuit Be Changed For Higher Frequency?

    After studying the circuit a little more carefully I can't really understand how the circuit operates. At first glance it seems like a peak voltage detection circuit, but it does not hold the peak value as most peak detection circuits normally do (IMHO). Rather it produces a varying positive...
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    Capacitance Measuring Circuit - Can This Circuit Be Changed For Higher Frequency?

    I wouldn't think that salinity changes very quickly so maybe occasional calibration of a resistance method is workable. Anyway, for your circuit to give meaningful results the capacitor's reactance would have to be very low compared to the resistance, probably by a factor of at-least 10...
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    Newbe need help with solenoid kicker project.

    I don't know much about thyristors/scr and you don't give a lot of circuit details to enable someone to recommend one for you. If I was in your situation, given that I also have minimal thyristor knowledge, I would google thyristor/scr circuits and see if a circuit or application is similar to...
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    Capacitance Measuring Circuit - Can This Circuit Be Changed For Higher Frequency?

    Mahonroy, Your circuit is also going to measure the resistance of the soil and my wild guess is that will influence your reading more than the capacitance. What you are measuring is a resistor in parallel with a capacitor and both are changing with moisture. Simply measuring the resistance, as...
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    Capacitance Measuring Circuit - Can This Circuit Be Changed For Higher Frequency?

    Mahonroy, I'm puzzled why you seem to think that you need a higher frequency to read larger capacitors. I would think the opposite is needed, lower frequency for larger capacitors. Even your simulation hints at that. For example, it confirms that higher frequencies give less range ("bottom...
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    question about shunt resistor

    Good point.. The schematic also says it can supply up to 20 amps. That calculates to 10 watts dissipated so some bigger wattage resistors are required.
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    Adding hardwired auxiliary input to car radio amp

    Some radios will automatically switch to the aux input when something is plugged into it. I suspect that's done through mechanical activation of contacts at the aux jack. It might be possible to disconnect the appropriate wires from those jack contacts and use a circuit that emulates those same...
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    question about shunt resistor

    jon5500, 10 amps through two parallel .1 ohm resistors = .05 ohms * 10^2 = 5 watts. The two 5w resistors in parallel can handle 10 watts so as already mentioned you should be okay. Be advised 5 watts generates a lot of heat, even 1 or 2 watts gets very hot. If touched it can burn you. It's...
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    Press on press off

    What happens if you hold the power button down during power cycles? That might mimic your jumper solution and/or provide a "tape down the button" solution. Looks like the 2302 is a mosfet transistor that seems capable of doing the on/off switching. Of course, it could be serving a different...
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    Press on press off

    Soldering a jumper across the switch will likely turn the unit on when power is applied, but without a schematic it's impossible to tell if that is a completely trouble free solution. IOW, keeping the switch permanently on via a jumper might have some adverse consequences. Alternatively...
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    3 Phase Motor - 3 Individual Circuit Breakers - Detect if 1 Breaker Tripped And Shut Down Motor

    I like the hall sensor idea, but I'm not sure I see a need for a Pic, or multiple Pics. Just use the three filtered DC signals, amplified if necessary, to drive an AND gate that controls the Op's 3 pole relay. Use a latching arrangement, maybe a fourth pole on the Op's relay, to make sure...
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    3 Phase Motor - 3 Individual Circuit Breakers - Detect if 1 Breaker Tripped And Shut Down Motor

    Mahonroy, Why is it necessary to kill the other two phases if one phase dies? Seems to me the other phases might draw more current, but judicious fusing on those phases should prevent damage. Okay, the motor might run slow, but if that is a serious problem maybe a tachometer alarm is a better...
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    3 Phase Motor - 3 Individual Circuit Breakers - Detect if 1 Breaker Tripped And Shut Down Motor

    hevans, An example of a latching relay would have one pole with it's NO contacts in series with it's activating coil. A momentary switch (push button) across the normally open contacts would have to be manually pushed for the relay to activate. Once the relay opens it cannot close until the...
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    3 Phase Motor - 3 Individual Circuit Breakers - Detect if 1 Breaker Tripped And Shut Down Motor

    hevans, Bypassing the circuit breaker may introduce a safety issue as voltage will still be presented to the motor when it appears to be turned off. True the motor loading will minimize the voltage level, but if someone is working on the motor and disconnects a winding it could cause a shock...
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    3 Phase Motor - 3 Individual Circuit Breakers - Detect if 1 Breaker Tripped And Shut Down Motor

    Might a "mini" breaker something like this suit your needs? They are designed for overseas power and are rated for 400v, 50 hz, but since they are current driven I would think it can work in the U.S. at the lower voltage and 60 hz. Cheap enough. If it satisfies your needs maybe others here...
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    I would appreciate advice-need to add earphones jacket to a radio

    Check out the app "air music control". It's mentioned in your radio's manual. It may allow you play through your smart phone and it's ear phone.
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    I would appreciate advice-need to add earphones jacket to a radio

    Well, since no one replied I'll try and help. The manual says the line out jacks can drive external speakers, but they would have to provide their own volume control. So I would think headphones with a built-in volume control should work. I also suspect that turning the radio volume control to...
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    Solder pins to small holes on my TM1637 4-digit display

    No electrical difference provided that you are able to make a good solder connection. As you may have discovered soldering from the wrong side can be very difficult or impossible because there may not be a copper circuit pad on the wrong side. In case of a single sided circuit board there is...
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    Capacitive dropper circuit

    One other problem I realized after seeing the improvement suggested by burtus: Each branch of diode circuitry only gets current flow for half a cycle. Therefore, to get an equivalent of 30ma (RMS) through each diode branch the total current for the circuit should be designed to allow a total of...
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