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DIY Stompboxes => Building your own stompbox => Topic started by: gonkulator_modulator on December 24, 2010, 04:18:26 PM

Title: Swapping collector and emitter with DPDT switch
Post by: gonkulator_modulator on December 24, 2010, 04:18:26 PM
Hi guys,

Could anyone post here the diagram of swapping transistor's collector and emitter with DPDT switch, please? I want to built both Devi Ever's Soda Meiser and Vintage Fuzz Master in one stompbox. This diagram was posted on Devi Ever's forum but unfortunately I didn't save it and now I have no access to that thread :(
Title: Re: Swapping collector and emitter with DPDT switch
Post by: Taylor on December 24, 2010, 05:57:23 PM
This is something that could be reasoned out instead of just told to you - I think it would be a useful way to start understanding how things work with electronics.

A DPDT is equivalent to 2 separate switches, each with one pole and 2 throws, which are switched at the same time. So think about what you want to switch:

1. You want the collector to connect to point x in position 1, and point y in position 2
2. you want the emitter to connect to point y in position 1, and point x in position 2

How would you do it? Give it a shot and I'll let you know how you did. I like when people give me homework, so hopefully you do too.
Title: Re: Swapping collector and emitter with DPDT switch
Post by: gonkulator_modulator on December 25, 2010, 09:26:16 AM
Well, I've got an idea, but I'm not sure if it works. I think I should read more information about switching :)

(http://i1230.photobucket.com/albums/ee485/gonkulator_modulator/Diagram.gif)
Title: Re: Swapping collector and emitter with DPDT switch
Post by: PRR on December 25, 2010, 01:09:43 PM
> I think I should read more information about switching

Always a good idea.

I'm not sure if it works.

That should work.
Title: Re: Swapping collector and emitter with DPDT switch
Post by: Perrow on December 25, 2010, 01:14:19 PM
Quote from: Taylor on December 24, 2010, 05:57:23 PM
I like when people give me homework, so hopefully you do too.

I seem to remember you giving people homework before  :icon_lol: Always a good way to attack a problem. Always easier to help someone who cares enough to try on their own.
Title: Re: Swapping collector and emitter with DPDT switch
Post by: gonkulator_modulator on December 25, 2010, 02:13:26 PM
I've just found some information about the power supply polarity reverse. They suggest exactly the same switching diagram. Well, I have reinvented the wheel but sometimes that's quite useful :) Thanx everyone for support :)
Title: Re: Swapping collector and emitter with DPDT switch
Post by: PRR on December 25, 2010, 06:18:41 PM
> I have reinvented the wheel but sometimes that's quite useful

To understand it, you should be able to invent it.

Being not-the-first to invent something may rob you of fame and fortune. However we don't know who was first to publish the DPDT Reversing Switch, and I bet he got no fame or fortune from it.

Knowing it at the level that you can re-invent it when needed means you have the basework for other useful variations.