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If you were controlling a DC load and the Load and Arduino can share a common ground reference, then a MOSFET might be practical. However, in your case you want to control 120VAC. That means the AC load needs to be isolated from the DC control signals. You could use a MOSFET and separate power supply to control the existing mechanical relay, or you can ...


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A resistor will work fine. You could also use a 24V 1W zener diode (eg. 1N4749) if the 72V is reasonably well regulated. That's an odd relay- they appear to use the coil (or maybe a second resistor?) as a voltage divider to derive a voltage for the indicator LED. The reverse voltage waveform across the LED at turn-off might be interesting if they are using ...


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Using a resistor will work as relays are fairly tolerant but if someone puts a similar relay in for some reason, the specs may be different. I’d suggest a simple transistor + zener diode regulator. You’ll probably want to use a heatsink as the transistor will probably get to around 30degreesC above ambient (your resistor would get hot as well unless you ...


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You can use whatever relay you want. There are a few considerations to take into account to make an optimal choice : choose a relay working on a voltage you already have (nb : the 3.3V from arduino will not serve, the 5V from the arduino regulator might or might not serve depending on the relay, but it's best to avoid it) you can't directly connect the coil ...


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Maximum load current is 4A. Switching frequency is very low; around 1Hz at most. The ambient temperature will be 50oC at most." The G3VM-61FR device uses a photovoltaic generator to produce a floating voltage that directly interfaces to two MOSFETs. The two MOSFETs can be wired antiphase (as in connection scheme A or, can be wired for DC connections ...


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If you are using the SSR for speed or wear out reasons, then you could put another mechanical relay in series. You would normally keep that one activated, but of you detect the SSR has failed, you would deactivate the mechanical relay. You could consider the same concept with another SSR, but it is possible that whatever supply V transients that might damage ...


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I might suggest some revisions of the version offered by @Russell McMahon that uses the 74C14 IC to drive the on and off function, if accepted. I like this design as it makes use of a bridge rectifier in an unusual way and it seemed quite sound until I put it to test. I used the IRF640 and the 220 kΩ between Gate and Source. The thing that made it work just ...


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I assume you mean " array of high-power MOSFETs connected in parallel", since 12V does not require multiple MOSFETs. Well, solid-state devices inherently tend to fail 'on' (unless you literally blow the leads or wirebonds off the device) and there is really nothing you can do about that except operate them conservatively, and even then they will ...


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I'm still not sure if this is even possible with this board, but I've realized something along the way. I thought the '8 Channel Relay Module' was the same as an '8 Channel Solid State Relay (SSR)'. I understand now that they are not. The '8 Channel Relay Module' can only be used with an input signal from something like an Arduino or a 'Reflective ...


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A magnet pole moving over a coil causes a bipolar voltage pulse that depends on the speed of the magnet; there will be a peak, then a valley, each having the same volt-seconds product (area between the V versus time curve and the V=0 axis). The nominal best practice in such situations is to use the complicated pulse to trigger a one-shot, such as a '555 ...


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There's a lot to process here. I'll do my best. 1: as far as the diagram goes, I don't think you're connecting your transistors how they're supposed to be, at all. I'm guessing you're trying to amplify the coil's signal. 2: I'm guessing from the pictures that you have a rotating table where the magnet is placed and it travels above the coil. I don't think ...


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