I want a DC output of 0 V if the AC SPST is open (off state) and 5 V if the AC SPST is closed (on state.)
Please provide any circuit or solutions for this.
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Welcome! What have you tried so far? – winny Jul 09 '22 at 10:05
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1Before we can start to answer your question we need more information. Is the switch used for anything else other than indicating it's state? If so, what is it switching ? What will the 5/0V signal be used for, a logic level, a lamp, something else? But most importantly of all, what have you tried so far and why doesn't it satisfy your requirements? – Peter Jennings Jul 09 '22 at 10:25
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Is it an isolated 0V? – Tony Stewart EE75 Jul 09 '22 at 14:10
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2In the absence of any further information, my first thought is a USB phone charger connected to the output of the switch. – Simon B Jul 09 '22 at 16:43
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Will there be any AC current flowing through the switch? – Harper - Reinstate Monica Jul 10 '22 at 06:28
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You can use an AC input solid state relay or photocoupler like the PS2705 across the switch contacts, with a series resistor that provides something like 2-5 mA at the voltage being switched. The output of the optocoupler would then be connected with a pull-up resistor of perhaps 5k to a 5V supply. The voltage across the device's output transistor will be low (less than 100 mV) when the switch is open, and pulled up to 5V when closed. This assumes that the switch has a substantial load that will not be affected by a few mA when the switch is open. This will also work on DC.
PStechPaul
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