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[nievesoliveras]

@ Jesus


Thanks for the PM, I can only send the DPDT transistor setup by posting it here.

I assume you want to switch a Positave and a Negative

Now just before anyone says it's not right, (you may be right) I will do a search on the net about switching the negative rail using discrete transistors, however here is what the circuit should look like.

Ps, the only way to make it work is to use 2 seperate switches, or take a Positave feed via 2 NPNs (further up the line)  to feed either of the necessary transistors.
If using for light current under 1 amp, use BC 548s over this use BD range or the 2N3055's or try MOSFETS, or pick on the Darlingtons.

jim

Welcome @electricme !
Thank you for your prompt response to my question.
The difference is that only the positive is going to be switched.

I made a circuit from my study of logic circuits.  Maybe my logic is not the right one but it is a starting point.

Jesus

[Pirate88179]

Jesus:

This may or may not be helpful here but, thanks to a suggestion from Wilbyinebriated I made a device that pulses my AA battery that does not use up any power.

http://www.youtube.com/watch?v=XYhNw6SuTfA

I call this the Wilby's Bird experiment.  A joule thief, supercaps and leds being pulsed by Wilby's Bird.  This idea may come in handy for you at some point.

Bill

[nievesoliveras]

Jesus:

This may or may not be helpful here but, thanks to a suggestion from Wilbyinebriated I made a device that pulses my AA battery that does not use up any power.

http://www.youtube.com/watch?v=XYhNw6SuTfA

I call this the Wilby's Bird experiment.  A joule thief, supercaps and leds being pulsed by Wilby's Bird.  This idea may come in handy for you at some point.

Bill

Thank you @pirate !

If that bird were faster you would not need anything else to get that light going.
Very good experiment!

Jesus

[nievesoliveras]

@all

I finished my experiments with the battery switcher. Now I have the resources free to start experimenting on other thing. Now I will start with the resources that are left. I mean that did not get damaged experimenting, to build the transistor battery switcher.

It is expected to use and keep both batteries charged while working without stop.

Jesus

[nievesoliveras]

@all

I will explain the principle behind the logic circuit I presented here.
According to my readings, the joule thief transistor produces two different sparks of energy.
One when it turns on the LED and the other, when it turns off the LED.

With that said.
There are two diodes on the circuit.
1. After the collector
2. Before the emitter

The one after the collector is the charging diode. It is activated by the wire before it going to the base of two transistors.
The one before the emitter uses the bemf spark to hopefully activate the second group of transistors that will provide the alternated battery positive to the joule thief coil.

That is it! Hope for the best!

Jesus