Igor said:OOPS... Anyway, refer to CBE printed on PCB, it is right.
There's no CBE on my PCB board but I'm assuming (wrongly) that for the PN222A the Emitter is fitted at the top towards the Mic i/o as per the "half moon" transistor shape marked on the PCB? It's going to the 100K resistor & 24V supply?
I know I'm just a newbie (plus my brain is starting to hurt) but the schematic says the emitter goes to the relay & D2? Or have I lost the plot? LOL!
Disclaimer the attachment to this post is wrong but that is what I originally used, do not refer to this layout!!!! Use layout link at start of thread!!!!