RGs remote relay bypass

[Buffalo Tom]

How do I switch the +on/-off line?

Is that a SPDT switching between 12V and ground. OR is it just a SPST switching 12V on/off.

[antonis]

You don't have to necessarily involve 12V on ON/OFF input..

Just a voltage higher than I_baseX(R1+R2) + 0.7V..

I_base should be counted for relay initial(start up) current + LED current divided with Q1 DC current gain..

[Buffalo Tom]

Thanks antonis, So a SPST switch will do.. 12V is what I have so its easier to use that instead of reduced voltage. Thanks for explaining

[antonis]

Just realized I didn't answer your initial query..

Both your choices can be considered OK but the second one should give a "smoother" OFF..
(due to C1 discharging through R2 & Base..)
Also preventing potential shorting 12V source in case of SPDT switch malfunction..
(rare but not zero possibility..)