September 10, 200817 yr Author comment_159031 I want my Pearl Phono trannies they'll be done today Report
September 12, 200817 yr comment_159943 they'll be done today Any luck finishing those transistors Report
September 12, 200817 yr Author comment_160019 Any luck finishing those transistors yes, I need to find your address and take them to the post office. I'm a bit behind on the rest ... Report
September 16, 200817 yr comment_161378 Well, I soldered in the final transistors from Marc today, and..... the circuit not measuring right, no workie.... I will need trouble shooting assistance:mikey2: Report
September 16, 200817 yr Author comment_161393 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. Report
September 16, 200817 yr comment_161394 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 Report
September 16, 200817 yr comment_161396 Q3 30.6v, 26.68v, 30.3v the Q4 and Q4 base voltages are near 29v Report
September 16, 200817 yr Author comment_161489 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? Report
September 16, 200817 yr comment_161490 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 Report
September 16, 200817 yr Author comment_161491 So is the voltage at the transistor quad and output cap... have you assembled the second board? (i.e. do you have some extra parts laying around?) Report
September 16, 200817 yr comment_161492 f Also, did you remember to solder in the shorty to connect the top and bottom ground planes? huh ? Where is this on the board. Could this be the cause of my bad readings? Report
September 16, 200817 yr comment_161493 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 Report
September 16, 200817 yr Author comment_161494 huh ? Where is this on the board. Could this be the cause of my bad readings? heh.. check out the silk screen near C15. Report
September 16, 200817 yr comment_161501 heh.. check out the silk screen near C15. Ok, I see a jumper hole near C15. I guess I didn't read the big print right there Do you think that is likely my issue? Report
September 16, 200817 yr Author comment_161503 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. Report
September 16, 200817 yr comment_161505 I'm the typical engineer: When all else fails.... read the directions Report
September 16, 200817 yr Author comment_161515 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. Report
September 16, 200817 yr Author comment_161525 Darn! Now I have to sit here at work all day..... you look like you may not be feeling well? wait, is that the baby I hear? Report
September 16, 200817 yr comment_161530 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 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? Report
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.