Voodoo Lab Pedal Switcher

Nikifena · Post by **Nikifena** » 23 May 2009, 13:21

http://www.picvalley.net/u/2190/1743968 ... ZF0PdM.JPG
http://www.picvalley.net/u/2562/2051331 ... EcwZQL.JPG
http://www.picvalley.net/u/2679/4962315 ... fOkbmR.JPG

Enjoy

Buffered input is based over 1/2 OPA2134. Another 1/2 is not used.

trad3mark · Post by **trad3mark** » 23 May 2009, 13:33

no seriously...

THANK YOU!!!

i've been looking for something like this for sooooo long! i wouldn't even know where to start with reversing something, so someone reverse this, now.

Nikifena · Post by **Nikifena** » 23 May 2009, 17:22

^ Dude, this unit use microcontroller to contro relays from switches and from midi.
There is no necessary to copy the schem. It's so easy, but all information is in the microcontroller which one is read protected

trad3mark · Post by **trad3mark** » 23 May 2009, 18:31

aaww..... being an electronics noob has failed me again. back to trying to get my ff working.

Maxwell · Post by **Maxwell** » 26 May 2009, 20:18

Cool. The relay switching section looks very much the same as the GCX switcher. Basically the same setup I'd guess - relay, diode, and RC snubber circuit across the relay coil to reduce popping noises.

Evz · Post by **Evz** » 10 Nov 2009, 00:20

Would someone be able to draw out the isolated schem for one of the relay switches? i have seen the schematics for their use in channel switching (ala silver jubilee) but want to ubild a similar switcher myself.. would it be possible to get the schem for power buffering and individual relay control?

i want to make a similar controller with 6 switchables (hopefully buffered like these) no need for midi or anything like that.

Edit: i was looking some more at the pcb, they use the transistors to buffer the 12vdc signal right?

Maxwell · Post by **Maxwell** » 10 Nov 2009, 14:10

Here's an article that shows the basics of using a transistor to drive a relay:

http://www.jaycar.com.au/images_uploaded/relaydrv.pdf

Any relay-based switcher is doing something similar. The diode is important, because without it back EMF from the relay coils will fry the transistor.

KB · Post by KB » 11 Nov 2009, 10:13

Hi

This link may also be of interest

http://www.jimkim.de/html/guitar02_01.htm

This is an Eight loop switcher, using a 16F84 PIC. The code is on the site along with Circuit diagrams and a board layout.
there is also a Four channel switch which could be used for changing channels on your amp, or in a situation where you would normally use a latched switch. I attempted to build it but I could not get the PIC to program. I have zero programming skills and this was my first attempt at programming a PIC even if the Hex code is supplied it is a little beyond my skill level (for the moment).

For relay switching then

http://www.geofex.com/Article_Folders/r ... /rmtsw.htm

If you are looking for basic information there is lots of information about switchers on GEOFEX

http://www.geofex.com/Article_Folders/j ... uggler.htm
http://www.geofex.com/Article_Folders/f ... witchr.htm

If you are going to control multiple relays you could look into using a single chip like the ULN2803 although I have not attempted that myself.... yet

http://www.datasheetcatalog.org/datashe ... 828_DS.pdf

Hope the information helps.

Cheers, and don't burn yourself soldering

Kevin

Maxwell · Post by **Maxwell** » 13 Nov 2009, 16:47

Pretty cool... I actually built my own MIDI switcher, but using an AVR microcontroller. I don't know assembly but I do know C and since there are C compilers for it the writing of the firmware (which I did from scratch) was at least possible to figure out how to do, though it took a lot of work. Microcontrollers are pretty amazing in what you can do with them nowadays.