Cheep Bastich Bypass

[bean]

A few months ago I came across a couple videos (EEV BLOG and Evan Kale) and saw this sketch. I thought it might be a kinda cool alternative soft bypass worth trying so I added the relay and transistor switch. Anyway, forgot about it for a while but found my drawing today and breadboarded it. It works decently although it is probably not a substitute for some of the more reliable switching designs. But, it's got parts everyone has!

Couple things
- Doesn't seem to work with all relays but it does with the Kemet I listed.
- If you hold the momentary down it will cycle the relay about once a second. That might be cool in some applications...maybe not others.
- I added the 1k resistors and 100pF caps around the switch thinking it might help a little with de-bounce but I don't know if it's that necessary.

I have a small etchable layout for it but would rather wait for someone else to verify it/offer opinions before uploading it.



Video inspiration:

[amptramp]

It looks like Q1 has nothing pulling the base towards the emitter.  I am old school, I like to put a resistance between emitter and base just to eliminate any problem from leakage currents turning the transistor on.  Other than that, it looks good, like the CMOS inverter version of the same thing but with enough output current to switch a relay.

[bean]

It looks like Q1 has nothing pulling the base towards the emitter.  I am old school, I like to put a resistance between emitter and base just to eliminate any problem from leakage currents turning the transistor on.  Other than that, it looks good, like the CMOS inverter version of the same thing but with enough output current to switch a relay.

I gave the base-emitter resistor suggestion a try but it turns out it actually caused rapid cycling on the relay with light pushes on the momentary. So, I think it's better to leave that out.