Webby I'm, a bit lost. If you connect pin 1 of IC4 to ground that should pull the base of Q7 to ground, they are directly connected. You say Q7 base is at 12.7, can you double check your measurements?
While you are at it, measure the resistance between pin 2 of JP2 and each of the four terminals on the switch, with the switch in both positions. Do the same with pin 6 of IC3 and each of the four terminals on the switch (this is with the controller off).
While you are at it, measure the resistance between pin 2 of JP2 and each of the four terminals on the switch, with the switch in both positions. Do the same with pin 6 of IC3 and each of the four terminals on the switch (this is with the controller off).
Tech support Please
Hi Mark,
i have checked q7 with ic4 installed
c=0 b=12.7 e=3.5
Without ic4 installed
c=0 b=2.9 e=0
I measured all six terminals of sw1 with ic 3&4 installed and removed just to be thorough, i labeled the pins left to right front to back;
IC3&4 removed
JP2 pin2 33 rpm
pin
1=10.26k
2=short
3=short
4=7.80k
5=1.92
6=1.92
IC3&4 removed
JP2 pin2 45 rpm
1=short
2=short
3=10.2k
4=2.5k
5=2.5k
6=8.3k
IC3&4 removed
IC3 pin6 33 rpm
1=5.15k
2=5.11k
3=5.11k
4=2.69k
5=3.22k
6=3.22k
IC3&4 removed
IC3 pin6 45 rpm
1=5.15k
2=5.15k
3=5.11k
4=2.68k
5=2.68k
6=3.21k
IC3&4 installed
JP2 pin2 33 rpm
1=8.1k
2=short
3=short
4=5.6k
5=1.6k
6=1.6k
IC3&4 installed
JP2 pin2 45 rpm
1=short
2=short
3=8.1k
4=2.0k
5=2.0k
6=6.2k
IC3&4 installed
IC3 pin6 33 rpm
1=5.1k
2=3.0k
3=3.0k
4=2.7k
5=2.4k
6=2.3k
IC3&4 installed
IC3 pin6 45 rpm
1=3.6k
2=3.1k
3=5.1k
4=2.1k
5=2.1k
6=3.2k
Thanks for your help so far, i have just picked up some spare transistors and resistors just in case.
Cheers
webby
Hi Mark,
i have checked q7 with ic4 installed
c=0 b=12.7 e=3.5
Without ic4 installed
c=0 b=2.9 e=0
I measured all six terminals of sw1 with ic 3&4 installed and removed just to be thorough, i labeled the pins left to right front to back;
IC3&4 removed
JP2 pin2 33 rpm
pin
1=10.26k
2=short
3=short
4=7.80k
5=1.92
6=1.92
IC3&4 removed
JP2 pin2 45 rpm
1=short
2=short
3=10.2k
4=2.5k
5=2.5k
6=8.3k
IC3&4 removed
IC3 pin6 33 rpm
1=5.15k
2=5.11k
3=5.11k
4=2.69k
5=3.22k
6=3.22k
IC3&4 removed
IC3 pin6 45 rpm
1=5.15k
2=5.15k
3=5.11k
4=2.68k
5=2.68k
6=3.21k
IC3&4 installed
JP2 pin2 33 rpm
1=8.1k
2=short
3=short
4=5.6k
5=1.6k
6=1.6k
IC3&4 installed
JP2 pin2 45 rpm
1=short
2=short
3=8.1k
4=2.0k
5=2.0k
6=6.2k
IC3&4 installed
IC3 pin6 33 rpm
1=5.1k
2=3.0k
3=3.0k
4=2.7k
5=2.4k
6=2.3k
IC3&4 installed
IC3 pin6 45 rpm
1=3.6k
2=3.1k
3=5.1k
4=2.1k
5=2.1k
6=3.2k
Thanks for your help so far, i have just picked up some spare transistors and resistors just in case.
Cheers
webby
Re: Tech support Please
Webby I'm sorry but I can't tell you whether those resistances are OK or not- I'm working off Algar's schematic and I'm not sure I understand the way he has the adjustment section drawn. Also I don't know which of the six pins of the switch is which (I've never built Algar's version).
Can you re-check your measurements on Q7, it looks to me like you have labelled emitter as base and vice versa.
Assuming that is the case measure the voltages at pins 2 and 3 of IC4 when everything is connected and (not) running.
webby said:
Webby I'm sorry but I can't tell you whether those resistances are OK or not- I'm working off Algar's schematic and I'm not sure I understand the way he has the adjustment section drawn. Also I don't know which of the six pins of the switch is which (I've never built Algar's version).
Can you re-check your measurements on Q7, it looks to me like you have labelled emitter as base and vice versa.
Assuming that is the case measure the voltages at pins 2 and 3 of IC4 when everything is connected and (not) running.
Replacement Pulleys - Shipping 15 MAY
Sent the pulleys for you guys, check your email. Thanks.
Aengus, av-trouvaille, Kraljmatjaz, superhkm, jonk, DiyFan, SvErD, Limono.
Still no reply from: patriz, jlwong, Posthorn, Secips and Cedus.
Webby, the ohm measurements are difficult to trace in a particular circuit. Do these tests in sequence and report:
1) All IC's not connected, except IC1 (Battery current charge regulator is connected). Motor and battery connected.
2) Controller AC supply connected, and battery connected, both charger switches DOWN. Now battery should be charging. Confirm 18V at IC1, pin1, then Battery Voltage 13.5 to 13.8V (battery charged).
3) Insert IC3 (Voltage Reference)
4) Both charger switches UP, JP2 to GND reference (pins 2-3), check JP2 position using the PCB silkscreen. Confirm 5V at IC3, pin 6
5) Ground IC4, pin 1 on IC4 socket, motor MUST turn on full speed.
You must complete all these basic checks and insure the motor can run full speed before we go any further.
Thanks...
SB
Sent the pulleys for you guys, check your email. Thanks.
Aengus, av-trouvaille, Kraljmatjaz, superhkm, jonk, DiyFan, SvErD, Limono.
Still no reply from: patriz, jlwong, Posthorn, Secips and Cedus.
Webby, the ohm measurements are difficult to trace in a particular circuit. Do these tests in sequence and report:
1) All IC's not connected, except IC1 (Battery current charge regulator is connected). Motor and battery connected.
2) Controller AC supply connected, and battery connected, both charger switches DOWN. Now battery should be charging. Confirm 18V at IC1, pin1, then Battery Voltage 13.5 to 13.8V (battery charged).
3) Insert IC3 (Voltage Reference)
4) Both charger switches UP, JP2 to GND reference (pins 2-3), check JP2 position using the PCB silkscreen. Confirm 5V at IC3, pin 6
5) Ground IC4, pin 1 on IC4 socket, motor MUST turn on full speed.
You must complete all these basic checks and insure the motor can run full speed before we go any further.
Thanks...
SB
testing circuit
Hi all,
Thanks for the help so far.
I have just tried your suggestions, here goes;
IC1 pin1 27.5, is this because i dont have a battery connected yet, could this cause more problems?
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok?
testing Q7 i get c=0 b=12.7 e=3.5, i am pretty sure i have them labeled correctly. if i am looking at the PCB with the switches at the front, the collector is nearest, base middle and emitter furthest away from me?
I only get voltage on Q7 when IC2,4 installed, i presume this is normal?
Thanks again
webby
Hi all,
Thanks for the help so far.
I have just tried your suggestions, here goes;
IC1 pin1 27.5, is this because i dont have a battery connected yet, could this cause more problems?
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok?
testing Q7 i get c=0 b=12.7 e=3.5, i am pretty sure i have them labeled correctly. if i am looking at the PCB with the switches at the front, the collector is nearest, base middle and emitter furthest away from me?
I only get voltage on Q7 when IC2,4 installed, i presume this is normal?
Thanks again
webby
Replacement Pulleys - First Shipping 17 MAY
Sent the pulleys for you guys, check your email. Thanks.
Bakus11, Dave Melichar, 615498(Keith Fitzgibbon), analog_sa, Markgall, ZUM911
I shipped all the replacement pulleys that I could, the one that are left also include new pulleys, but I still didn't received the missing 2.5mm allen screws from Greg Nuspel, so I cannot ship them.
They are: Atiq19, Toaster, MikeWong, Mjounot,
Still no reply from:
av-trouvaille, superhkm, Kraljmatjaz, DiyFan, PostHorn, Secips, Cedus.
Sent the pulleys for you guys, check your email. Thanks.
Bakus11, Dave Melichar, 615498(Keith Fitzgibbon), analog_sa, Markgall, ZUM911
I shipped all the replacement pulleys that I could, the one that are left also include new pulleys, but I still didn't received the missing 2.5mm allen screws from Greg Nuspel, so I cannot ship them.
They are: Atiq19, Toaster, MikeWong, Mjounot,
Still no reply from:
av-trouvaille, superhkm, Kraljmatjaz, DiyFan, PostHorn, Secips, Cedus.
testing circuit
Hi All, Sylvain.
So i can assume the charging circuit is ok, should get the battery by tuesday. But what should be my next steps;
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok?
testing Q7 i get c=0 b=12.7 e=3.5, i am pretty sure i have them labeled correctly. if i am looking at the PCB with the switches at the front, the collector is nearest, base middle and emitter furthest away from me?
I only get voltage on Q7 when IC2,4 installed, i presume this is normal?
Any ideas what components to try changing, does Q7 look faulty?
many Thanks
Webby
Hi All, Sylvain.
So i can assume the charging circuit is ok, should get the battery by tuesday. But what should be my next steps;
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok?
testing Q7 i get c=0 b=12.7 e=3.5, i am pretty sure i have them labeled correctly. if i am looking at the PCB with the switches at the front, the collector is nearest, base middle and emitter furthest away from me?
I only get voltage on Q7 when IC2,4 installed, i presume this is normal?
Any ideas what components to try changing, does Q7 look faulty?
many Thanks
Webby
testing circuit
Hi All,
Just me being a pain again.
I have been testing some more, and wanted to verify a few things please.
I followed component to component continuity testing as per the circuit diagram, with all IC`s in. Things looked fine, so iI was checking collector to emitter for resistance / shorts and found Q8 collector and emitter short, removed it and solder points for pin 2&3 still short.
So I suspect Q2 as the collector conducts to ground and none of Q1 pins ground.
Am I correct suspecting Q2?
Would someone be kind enough to check this on a working board.
Yours, confused
Webby
Hi All,
Just me being a pain again.
I have been testing some more, and wanted to verify a few things please.
I followed component to component continuity testing as per the circuit diagram, with all IC`s in. Things looked fine, so iI was checking collector to emitter for resistance / shorts and found Q8 collector and emitter short, removed it and solder points for pin 2&3 still short.
So I suspect Q2 as the collector conducts to ground and none of Q1 pins ground.
Am I correct suspecting Q2?
Would someone be kind enough to check this on a working board.
Yours, confused
Webby
Webby:
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok? Yes, SW3 (charger On/Off, to Off=DN), SW2 (Circuit On/Off, to On=UP). IC3 is the 5V Voltage reference chip, its output is pin6 = 5V, so it is Ok.
For the transistors pins identification, just download each datasheet from the net. Q7= BC557. The transistor body should match the pcb silkscreen image printed on the PCB. See the included image. It is also included into the documentation. BC557 pinout is C,B,E, see image.
Your Q7 voltages don't make sense. If you put IC4, pin1 to ground, Q7 base should be Zero, not the collector. Check again.
If Q8 is shorted, you won't have any voltage on your motor. Q6,7 and Q8 form a shunt regulator, shorthing more or less voltage to ground to control the motor speed. Q1,Q2 are a serie regulator keeping the motor's voltage constant even if the battery voltage drops while using the controller. The Motor voltage will also be different for different motor current because R4, is a current shunt sensing element and will control Q2 accordingly.
I don't have an actual PCB myself. Just my first own version that is different from you own PCB.
Also make sure that VR1 multiturn potentiometer is not set to zero ohm, or you want be controlling the motor at all. A good starting pot is to set it near its middle range, lets say 20K. Measure it between IC4 pins 6-7 (with the power OFF).
What is your setpoint voltage (R11 input voltage)? This is the voltage controls by the front speed pots and DIP switches. Also if it is 0V, your motor won't turn. Make sure it is set to maximum, around 5V (the same 5V reference IC3, pin6)
Checking IC3 pin6 i get 5v when sw2=up sw3=dn, is this ok? Yes, SW3 (charger On/Off, to Off=DN), SW2 (Circuit On/Off, to On=UP). IC3 is the 5V Voltage reference chip, its output is pin6 = 5V, so it is Ok.
For the transistors pins identification, just download each datasheet from the net. Q7= BC557. The transistor body should match the pcb silkscreen image printed on the PCB. See the included image. It is also included into the documentation. BC557 pinout is C,B,E, see image.
Your Q7 voltages don't make sense. If you put IC4, pin1 to ground, Q7 base should be Zero, not the collector. Check again.
If Q8 is shorted, you won't have any voltage on your motor. Q6,7 and Q8 form a shunt regulator, shorthing more or less voltage to ground to control the motor speed. Q1,Q2 are a serie regulator keeping the motor's voltage constant even if the battery voltage drops while using the controller. The Motor voltage will also be different for different motor current because R4, is a current shunt sensing element and will control Q2 accordingly.
I don't have an actual PCB myself. Just my first own version that is different from you own PCB.
Also make sure that VR1 multiturn potentiometer is not set to zero ohm, or you want be controlling the motor at all. A good starting pot is to set it near its middle range, lets say 20K. Measure it between IC4 pins 6-7 (with the power OFF).
What is your setpoint voltage (R11 input voltage)? This is the voltage controls by the front speed pots and DIP switches. Also if it is 0V, your motor won't turn. Make sure it is set to maximum, around 5V (the same 5V reference IC3, pin6)
Attachments
(From Canada to the Netherlands)testing circuit
Hi All, Sylvain,
Received the replacement pulley, thanks for sorting this out, great job!
I have the battery at last, so have checked the charging circuit etc, this appears to be charging ok and supplying power to the circuit from battery, good!
Still cannot get the motor running.
Have changed Q8 and Q6, just to see, no change.
VR1 is set to 20K
IC3 pin6 = 5v
R11 setpoint 5v
VR2 & VR3 = 5v
I have all the datasheets to confirm IC`s and transistors,
I have rechecked Q7 and am still getting c=0 b=12.7 e=3.5 and the orientation is correct.
I think the first problem is Q2, shouldn't the collector be putting out 6v, looks that way on the diagram.
Are the reading from Q1 ok?
q1 c=12.6 b=13.1 e=13.7
The rest of them.
q2 c=0.1 b=12.5 e=13.6
q3 c=.6 b=.3 e=0
q4 c=1.8 b=.3 e=0
q5 c=13.7 b=.6 e=.3
q6 c=0 b=3.5 e=0
q7 c=0 b=12.7 e=3.5
q8 c=0 b=0 e=0
Could someone with a working circuit give me their transistor readings please, would be very grateful.
I am not sure what to do next, so any ideas?
Thanks
webby
Hi All, Sylvain,
Received the replacement pulley, thanks for sorting this out, great job!
I have the battery at last, so have checked the charging circuit etc, this appears to be charging ok and supplying power to the circuit from battery, good!
Still cannot get the motor running.
Have changed Q8 and Q6, just to see, no change.
VR1 is set to 20K
IC3 pin6 = 5v
R11 setpoint 5v
VR2 & VR3 = 5v
I have all the datasheets to confirm IC`s and transistors,
I have rechecked Q7 and am still getting c=0 b=12.7 e=3.5 and the orientation is correct.
I think the first problem is Q2, shouldn't the collector be putting out 6v, looks that way on the diagram.
Are the reading from Q1 ok?
q1 c=12.6 b=13.1 e=13.7
The rest of them.
q2 c=0.1 b=12.5 e=13.6
q3 c=.6 b=.3 e=0
q4 c=1.8 b=.3 e=0
q5 c=13.7 b=.6 e=.3
q6 c=0 b=3.5 e=0
q7 c=0 b=12.7 e=3.5
q8 c=0 b=0 e=0
Could someone with a working circuit give me their transistor readings please, would be very grateful.
I am not sure what to do next, so any ideas?
Thanks
webby
Glad guys the new pulleys are perfect. But the one to really thank is Greg. His the one that worked really hard to find the solution and make it possible. I just helped him with the shipping logistic. It was the least I could do after all he did. Thanks again Greg.
I hope you'll all enjoy the great music you will get from your TT project.
Hi Welly. Yes, indeed you really need 6V at the output of Q2. One way to check the circuit is to bypass Q2 with a jumper. Now you'll get 12V at the motor. Make sure to don't do that for long, because if Q8 conduct full blast it will let go a lot of current. If Q2 look strange, them double check the resistor values around Q1-Q2.
I hope you'll all enjoy the great music you will get from your TT project.
Hi Welly. Yes, indeed you really need 6V at the output of Q2. One way to check the circuit is to bypass Q2 with a jumper. Now you'll get 12V at the motor. Make sure to don't do that for long, because if Q8 conduct full blast it will let go a lot of current. If Q2 look strange, them double check the resistor values around Q1-Q2.
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