voltage regulator +/-

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there will be a dead zone around zero volts
you will need 2 diodes in the base circuit to compensate for that
 
I can live with a small dead zone. after all, there may be a reason of me to stop the motor all together rather than having it either one way or the other.
 
here is a re-draw of what I had before. its still not complete, but its easier to understand anyway.
http://www.killerkittykats.net/quik/cato/circuit of interest2.JPG

edit: I was looking at metakron's circuit, and I understand it now. its more complete than mine =].

metakron, did you draw it in tinycad? if so, you should send me the file so I can play around with it.
 
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no prob, I redrew it:
http://www.killerkittykats.net/quik/cato/h-bridge1.png

I also posted the tinycad file:
http://www.killerkittykats.net/quik/cato/
its called tinycad h-bridge1.dsn, save the file or it will open as code =/

p.s. I know there is no filter after that bridge rectifier, which would cause major problems. which brings me to my next point, what would be a good way to filter it? just caps? pi-filter? poor man's pi-filter? (uses resistors instead of inductors)?

edit: your resistors are labeled in 10^3 ohms, right?
 
4k7 means 4.7k. If I had a 4.7M resistor it would be 4M7. I just used 1M for 1 meg. .1 is a tenth of an ohm.

A single large capacitor is decent for a filter, but be sure your diodes can take the surge when powering on.
 
a tenth of an ohm? I didn't know they made them that small =]
 
once you guys review it, you should help me pick values of my parts =]

1 Bridge Rectifier(4 diodes)
1 Output Transformer
1 POT
4 Transistor NPN
4 Transistor PNP
2 .1u,Capacitor
2 1M,Resistor
4 4.7k/2.2k ohm,Resistor
4 47/22 ohm,Resistor
2 CAP1,Electrolitic Capacitor 2000uF
1 L,Inductor
2 LM5532,OpAmp

also, I want to put a circuit breaker in. at what value should I have it cut out?
 
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Cato: I might not have any time left tonight to figure out how to do it in Tinycad.

If you plan to run more than five amps, you should change the 4.7k resistors to 2.2k and the 47 ohm resistors to 22 ohm. You need a big capacitor across the power supply, at least 2000 microfarads. Each potentiometer needs to have both ends across the power supply. One must be wired backwards to the other. Use at least 5k, 10k is better, and it will work just fine with 1 megohms. One wiper goes to each input of the circuit, separately. At ten amps the .1 ohm resistors are going to dissipate 10 watts each, so use your best judgment there. You can probably do without them entirely.

Where the sets of four transistors are, you have the left set correct and the right-hand set wrong. The two sets are the same. I just mirror-imaged them.

The capacitors at the inputs of the op amps do not have to be polarized.

I don't know the op amp that you are using. It's probably OK.
 
The capacitors at the inputs of the op amps do not have to be polarized.
Click to expand...
I know, it was the smallest cap tinycad had, so I used it there because space was limited.

updated circuit:
*edit: link removed, look for an updated version below.*
 
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You're almost there. One wiper goes to one op amp input and one goes to the other. They are not joined. It is OK to change the 4.7k to 2.2k and the 47 ohm to 22 ohms right away, and it doesn't make a lot of difference unless you are pulling more than 5 amps.
 
Just make sure that the minus side of the bridge rectifier is actually connected to the circuit. The diagram doesn't show this. Other than that, you're there. I think this will work as is.

Also, wish me luck at my new job. :)
 
Yep, that looks like it will do it. Good luck.

Also, I think this circuit may need to have a load at all times. This will help make sure that the transistors that are supposed to be off are turned off. A 4.7k resistor should do it.
 
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