Hello,
I am an electronics novice, so please go easy on me.
I am attempting to make a circuit that detects when mains (AC) voltage is present.
The number of volts and amps is not important, just whether it is on or off.
The voltage state will then be fed back to an MCU (EPS32).
In my circuit, I am using an HCPL3700 IC. According to the datasheet, the correct resistor for my 240V input is 60K.
So, I wired up the circuit with a 60K resistor and everything worked as expected, except for one small issue - the resistor gets VERY hot.
To try and help with the heat problem I changed the circuit to use 2 x 30K resistors (one on the live and one on the neutral) and increased them to 2 watts each.
The circuit still works but the resistors are still getting very hot.
I don't like the heat because I plan to mount the circuit in a plastic enclosure when it is complete and this circuit will be powered 24/7.
Do I have the wrong wattage resistors, or is there a better way to detect AC voltage?
Thanks.
I am an electronics novice, so please go easy on me.
I am attempting to make a circuit that detects when mains (AC) voltage is present.
The number of volts and amps is not important, just whether it is on or off.
The voltage state will then be fed back to an MCU (EPS32).
In my circuit, I am using an HCPL3700 IC. According to the datasheet, the correct resistor for my 240V input is 60K.
So, I wired up the circuit with a 60K resistor and everything worked as expected, except for one small issue - the resistor gets VERY hot.
To try and help with the heat problem I changed the circuit to use 2 x 30K resistors (one on the live and one on the neutral) and increased them to 2 watts each.
The circuit still works but the resistors are still getting very hot.
I don't like the heat because I plan to mount the circuit in a plastic enclosure when it is complete and this circuit will be powered 24/7.
Do I have the wrong wattage resistors, or is there a better way to detect AC voltage?
Thanks.