Full wave bridge rectifier problem

Thread Starter


Joined Jul 13, 2017
You circuit seems a very complex way to meet your requirement.
If you only need to know if the relay contacts are open or closed why not use an AC opto isolator such as the TLP290.
It would only need a resistor to limit the input current and a pull up or pull down resistor on the microcontroller digital input port. most microcontrollers have the option of enabling a weak pull up resistor on the inputs so in that case you would only need one resistor and a TPL290 (Or similar.) for each relay output.
To avoid having to take a few sample readings in the software to avoid the zero crossing problem you could add a capacitor across the inlut to the microcontroller.
At first I suggested use an optocoupler, but this is not confirmed.