Auto-off bypass circuit

[bsas]

Hi all,

I was wondering if anyone knows how to build a true-bypass circuit that automatically shuts down when the battery dies or the power dies out. I can see that in the "TC Electronic BonaFide Mini Buffer Pedal" and I though was super cool that the buffers just bypass when it runs out of power.

So, does anyone have a sample circuit for this? I imagine is something "similar" to a millennium bypass circuit, right?

Thanks!

[Ciaran Haslett]

Look up any of the non latching relay bypass options.  Basically, when engaged, the relay is held in a constant energised state.  When disengaged (or power failure) the relay is de-energised and defaults to its non powered state...which you would wire for true bypass.

The problem with this is that the relay (being constantly powered up) can significantly contribute to current consumption (around 20mA depending on relay).