No opto. I can't see where it sense speed from. I took motor part and it is just basic motor. Two wires come from housing. They join as shown in my diagram.

 

tacho is on pin 8, whats on your circuit

 

Page 24? 10-20

 

page 25 fig 10-20, Atmel chip

 

I will go over this diagram again and see if I made a mistake. Sit tight.

 

My board looks more like this diagram and I am pretty sure my hand drawn is accurate. Where do you think it is wrong?
TEMEC IC u211B Page 2

 

could be C11, pins 2 -16.


i have been looking at the Atmel datasheet, same chip...

 

I'm going by the T that was stamped on the original IC.

 

I'm thinking this is C4 on page 2 of the TEMIC IC datasheet. It makes sense that it is not sensing from this part of the circuit. My voltages on pin 8 are zero at all times. I'm not sure what the solid single line at the end ofpin 7 circuit is and same at end of pin 8? Do they join together or is this something else? Also, not sure what Solid block with single line above it is on pin 8 circuit?

 

So if your circuit is the same as page 2 Temic, it maybe C11, across pins 2,16. Its 2.2uF electrolytic cap, which is providing the reference voltage for the speed pot, the wiper of which is connected to pin 11, what voltage is across pins 2 and 16, and pin 2 and pin 11 with the speed control adjusted.

 

Pin 8 is the speed sensor feedback, from the tacho, if your motor hasn't got a tacho, then there wont be a voltage on pin 8.

 

Pin 11 is 1.53 VDC and pin 16 is -5.01 with reference to pin 2. Both maintain after drop-out

I'm thinking C11 is the C155 tantalum cap in my diagram located in top right corner. It seems to be the only path between pin 2 and 16 on this controller

 

I still think the drawing you did, posted is wrong,

 

The voltage on pin 11 should sweep up and down when you alter the speed pot.

 

You keep saying my drawing is wrong but you don't say where? I drew this right off the PCB and i've gone over it five times. Where is it wrong?

 

Please try with a 2.2μf first.

 

Will do. Grabbing bite to eat while soldering iron heats up. Back shortly with an answer.

 

I have several caps here, some which have not been identified as of yet but I can't find a 2.2 uF. Can I join two of something in series/parallel?

 

Try two 1uf 16V in parallel. That is close I guess. Mount the other way. Not the very first way you soldered

PS I may not reply later as my home connection is having issues. I may not log in from home.

 

I installed a 2.2 uF electrolytic in its place and same result. May have ran a tad longer but not sure. maybe just wishful thinking