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9 votes
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Relay contacts temporarily have resistance after closing

The JS1-12V-F just isn't good enough for low current applications such as testing PCB components. You need a relay with a specified operating contact current that can be as low as 100 μA (or even ...
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  • 389k
3 votes

Control two or more channel relay using a single signal pin from an Arduino

It's definitely possible. You could make a PWM DAC and use comparators to trip at the desired threshold. This approach will be easier if you only need one relay on at a time. It could be expanded ...
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3 votes

What's the purpose of the form b in 4a1b relay?

Form B is for a low current DC capable switching contacts. They have different material that makes it suitable for DC wet making and breaking that AC only contacts do not need (because if the zero ...
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3 votes

What's the purpose of the form b in 4a1b relay?

Typically two things: one, so it can latch on (requires NO); two, to read state of the remaining contacts (NO or NC will do). This is more obviously useful in big contactors, where you can't spare a ...
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3 votes

How to operate a relay (24 VDC 8 mA) from a 4-20mA signal?

It would be better to use a comparator with a separate power supply, which would allow the use of a more robust relay than the sensitive one you've found, however here is a way to that does not ...
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2 votes
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Why does my electric oven relay have a time delay?

Thanks for the clarification in your question and the comments below your question. I have never seen one of these although it is similar to a hob ring controller but without any setpoint adjustment. ...
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2 votes

Relay contacts temporarily have resistance after closing

Could you use an opto-MOS photocoupler? Here is one for about a dollar that has less than 100 mOhms ON resistance and can handle 2A at 40V. However, it does not have a NC contact. You can get an ...
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2 votes
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Circuit to turn relay on/off based on button press

Here is a very simple 5V circuit. You can add a logic-level MOSFET or a BJT + base resistor and a flyback diode to drive a relay. Gates can be 74HC00. simulate this circuit – Schematic created ...
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2 votes

Relay implementation of Muller C-element

If you want to use the C-element in arbitration / asynchronous logic, then a so-called MrGo circuit - a Seitz arbiter with an anti-metastable element - is a much more robust solution. All async ...
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1 vote

Latching relay circuit design

Your relay is a dual coil design with a common negative terminal, 12V operated, with 48 ohm per coil (250 mA), according to the datasheet. This means you do not need a "push-pull" circuit to ...
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  • 3,899
1 vote

Keep having to replace 5 V relay - fridge thermostat replacement

Priorities First: Ground the fridge, OK, I am an electric inspector by actual trade, but you should newer power unearthed appliance unless its specifically designed to do so (too much to explain). all ...
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  • 131
1 vote

Control two or more channel relay using a single signal pin from an Arduino

You can combine clock and data in a single signal and reconstruct both using an R/C lowpass filter for the data status. A shift register can receive this and provide parallel data outputs. Assume the ...
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1 vote

Control two or more channel relay using a single signal pin from an Arduino

A simple way to get it down to two pins (I know you said one, but if you can deal with two, this may be worth considering) with a bit of simple logic circuitry: Use a serial-in/parallel-out shift ...
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1 vote

Relay module input giving off voltage

It sounds like there is a pull-up on the signal input on the relay module. You need to bleed away any current coming from that input. Add a 10 kΩ resistor between signal and GND and see if that cures ...
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  • 161k
1 vote

Is signal point in a relay isolated from power points?

Yes you can use the relay to isolate it. Note that in the drawing, the two negatives of the supply are not connected. Do not connect the GND/negative of the Arduino to the negative of the power supply ...
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1 vote

Switch on when voltage detected

You could apply your AC signal to a current buffer. The output of the buffer would be a replica of the signal which you could process without removing power from the original AC signal itself. Pass ...
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