Residual Current

[ibwev]

In the circuit attached below, the led on RA5 will blink when pin RB4 is high. After reset with SW 2 closed and SW 1 open, the led does not blink (as expected). When I close SW 1, it will start to blink (as expected). However, when I open SW 1 it will continue blinking UNTIL I open SW 2. How can I prevent current from the relay from affecting pin RB 4 after SW 1 has cycled and SW 2 is closed?

 

[MikeMl]

Why do you use an AC relay, a Triac, an opto-coupler to switch the relay when a DC switching circuit would have worked more easily (since the AC circuit and the DC PSU for the PIC share a common ground)?

 

[WTP Pepper]

R2 should be between the ADJ pin on the LM317 & ground and NOT on the Vout to ground connection.

 

[ibwev]

Why do you use an AC relay, a Triac, an opto-coupler to switch the relay when a DC switching circuit would have worked more easily?

The AC relay is part of an established circuit that I am attempting to control with the pic.

 

[ibwev]

R2 should be between the ADJ pin on the LM317 & ground and NOT on the Vout to ground connection.

View attachment 73483

Thanks for catching that mistake. I had it correct on breadboard but not schematic.

 

[ibwev]

Would a varistor work for protecting the circuit from the inductance of the AC relay?

The one in the diagram is MOV-07D820K. Varistor voltage is 82 V and Maximum AC volts is 50, Max DC is 65 and energy is 5.5J.