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Posted

okay.

voltage across R2?

voltage after regulator (R8)?

did you install R27 (47k)?

voltages at all three legs of Q5 and Q3 (ok, and Q4)? edit: referenced to ground

are both boards not working? verify all resistor values.

Posted

input voltage from big cap 46.8 volts (don't know if too high an input voltage can screw the circuit)

across R2 .08v

at regulator input 46.7v at output 30.7v

at zener 9.45v

R27 47k is in

voltages at Q3, Q4 and Q5 are where it really gets fucked up.... stand by

Posted
Q3

30.6v, 26.68v, 30.3v

the Q4 and Q4 base voltages are near 29v

for Q3 you should have around 0.6V across the base-emitter junction. You didn't identify which reading was which leg.... I'm going to guess the collector is at 30.6v (based on the output of the psu regulator voltage) in which case something is wrong here. Verify R13 and R16 are the proper values and R13, R16, Q3 are soldered properly. If you have a diode check function on your meter, verify that you are getting a diode drop across base-emitter, but I'm guessing this critter is bad.

Also, did you remember to solder in the shorty to connect the top and bottom ground planes?

Posted
Q3

30.6v, 26.68v, 30.3v

the Q4 and Q5 base voltages are near 30v

So is the voltage at the transistor quad and output cap...

The resistors are all correct, and I ohmed them out before install.

After building an M

Posted
have you assembled the second board? (i.e. do you have some extra parts laying around?)

The second board is assembled, but I did not put in the transistors you sent,

until I debug this board

Posted

heh, I just looked at your pics.. it's not populated. Dew eet!

It's from the negative terminal of C15 to the hole that's right below C15. You can see an arrow pointing to a white line on the top of the silk even when C15 is installed. The text is "behind C15". This the negative of the caps will be connected to that empty hole, and hence the top ground plane.

Posted
Darn!

Now I have to sit here at work all day.....

amateur. check out my board pic I posted and zoom in, you'll see what I'm talking about.

for everyone else :) the easiest way to install this is just bend the leg from the capacitor over before you clip it and solder it in.

Posted
you look like you may not be feeling well? wait, is that the baby I hear?

Yes! the wife needs to take her into the doctor's office, so I have to sit the other kids :D

I am an amateur!! Aero Engineer, so I have enough electrical knowledge to be dangerous :)

Does R27 always remain as 47K, or do you change it based on resistor load reqmt for the cart?

Or is it that if you parallel in a 100ohm, the 47k ohm becomes insignificant and the total resistance is essentially 100ohm?

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