picktone true bypass system stripboard

[PStevenson]

well not a direct clone but it does the same thing - it uses a tact switch (or whatever is in the pedal already) to activate a mechanical relay so you can get rid of your buffer (even though I personally think buffers are a good thing)

you press the button - the relay turns on and stays on
press it again and it turns off.

it is small enough to fit in some pedals though I would probably make a few external units to bypass groups of pedals and whatever

anyway I hope you like it.

http://www.paulinthelab.com/2013/04/soft-latch-true-bypass-relay-switch-for.html

[IvIark]

Excellent stuff, nice one Paul.  I've wanted to do something like this for a while that would be small enough to attach to the bottom of the box with velcro in the space the battery traditionally goes, and 20 x 8 would make that pretty much perfect.  I was looking at some of the IC options but they always seem complicated enough for them to end up too big to put in the space!

[PStevenson]

cheers dude. I saw it in your requests thing earlier - someone mentioned programming PICs etc. and I just couldn't let that happen when you can do it with transistors.

it's definitely a useful thing to make - I'm going to use it for other stuff like controlling all the lights in my house from a junction box - make people think my house is haunted for a bit of a joke.

[Geezer]

Thanks Paul!

I can put this one to use in both my pedals AND my amps for channel switching!

Nice small package

Geezer

EDIT: Is the schematic linked along with the vero the same circuit??
I've been trying to trace out the circuit, matching the vero up with the schem and I can't reconcile them(?)
I'm sure I'm just misreading something.......

[PStevenson]

yes they do, however if there was ever an error in something it would be the schematic because I always make them second after I've built the veroboard

just FYI: the vero has actually been built and works

[Madferret]

Excellent circuit Paul, you mentioned using this with your lights so am I right in thinking that you could use this with a variety of switching systems rather than just pedals?

[PStevenson]

if the relay is rated to handle it - yes you can use this to switch anything really because it wouldn't be at mains potential at anywhere in the control part of the circuit.

it's quite similar to the circuit used in anything that has a standby button on it like TVs and so on because it's cheaper to build this type of thing than it is to use actual switches.
you'll probably find that this circuit is cheaper than a 3PDT switch

[Geezer]

Thanks for the clarification Paul! I'll follow the vero.....

I have mostly reconciled the schem to the vero (just a few resistors mislabeled & Q2/Q3 reversed), but have one "snag" that I want to double check with you........on the vero, Relay pin 2 is connected to 9v, and on the schem it goes to ground. I assume (following the vero) that Relay pin 2 to 9V is correct(?)

The reason I ask for clarification is that all the other corrections to the schematic were simply mis-labeling....this is the only actual connection that differs between the two.

Thanks again!  Geezer

[PStevenson]

shit yeah, the relay should go to the 9v as it does on the vero - this is the problem with doing the schematic last.

I see what you mean about the mislabelling of resistor numbers - it's just EAGLE is a bit of a pain in the arse and I was tired by that point.
I'll change the relay connections on the schematic now.  

[Geezer]

GREAT! Thanks for the reply, Paul!

NOTE: See updated drawing further down the thread.....the Millenium bypass I added was unnecessary

Besides, I had the relay drawn incorrectly.

Geezer

[PStevenson]

cool, I guess that's something else I neglected to mention - the circuit will drive the LED aswell as the Relay. I didn't put it on mine cause I was going to use This other little circuit that powers a dual colour LED so it goes red when inactive and green when active http://www.paulinthelab.com/2012/04/red-on-green-off-for-selector-swtiches.html 

[Geezer]

Paul, so will the circuit drive an LED "as is", or is the extra circuit necessary?
If "as is", where are the connections for the LED made.....across the relay coil?

Thx, G

[PStevenson]

- aye just across the Relay coil - there is usually some kind of protection diode put across relay coils anyway to prevent flyback current but with a sub miniature relay there wasn't any point really

but yes - it's fine with an LED across the relay coil

[Geezer]

OK, here's an updated, simplified vero (simplified from the Millenium Bypass I had added on the previous version) with the LED and a CLR added.

Thanks again for the circuit, Paul.

Geezer