Thanks for the video great illustration. It is definitely normal for these models of VARIAC to have discrepancies between their actual output vs the labeled values surrounding the dial or its analog Voltage meter built into the front. Mine is off by almost 30Vac at some points. One thing I thought would be helpful to add is reminding people that using a Full Wave Bridge Rectifier will result in the output Vdc being roughly 1.41x higher than the Vac input because its value is (RMS) i.e. an average. So don’t be surprised if maxing the VARIAC to 130Vac gets you a reading of ≈ 180-184Vdc output from the rectifier.
Thanks Daze. That was quite educational. There are many attempts around ro reuse treadmill motor and there are challenges - yes, these motors often have a low torque. So two ideas - trade RPM for tongue or use electronic system with feedback and PID. I am pushing toward PID - quite tricky but promising.
I find treadmill motors come in three sizes. The smallest ones are low torque high RPM and are found on inexpensive home treadmills. Medium ones are very usable and found in hight level home treadmills. The best come in commercial treadmills. As you said you can trade RPM for torque but the smallest motors are kind of a waste unless space is an issue or very high RPM are important. How are you accomplishing PID control? I have thought about using Arduino and a digital potentiometer to control an SCR for a sort of homemade setup but it hasn't been enough of a priority for me to mess with.
@@dazecars I am using Arduino for PID control. Rectifying mains, then taking PWM generated by Arduino and modulating DC with MOSFET. Motor has an encoder on the shaft and providing feedback to the Arduino that calculating PID constant speed function. That part is done already, now I am adding some safety functionality - overcurrent protection, overspeed protection, temperature protection, soft start.
Thanks for the video great illustration.
It is definitely normal for these models of VARIAC to have discrepancies between their actual output vs the labeled values surrounding the dial or its analog Voltage meter built into the front. Mine is off by almost 30Vac at some points.
One thing I thought would be helpful to add is reminding people that using a Full Wave Bridge Rectifier will result in the output Vdc being roughly 1.41x higher than the Vac input because its value is (RMS) i.e. an average.
So don’t be surprised if maxing the VARIAC to 130Vac gets you a reading of ≈ 180-184Vdc output from the rectifier.
Thanks Daze. That was quite educational. There are many attempts around ro reuse treadmill motor and there are challenges - yes, these motors often have a low torque. So two ideas - trade RPM for tongue or use electronic system with feedback and PID. I am pushing toward PID - quite tricky but promising.
I find treadmill motors come in three sizes. The smallest ones are low torque high RPM and are found on inexpensive home treadmills. Medium ones are very usable and found in hight level home treadmills. The best come in commercial treadmills. As you said you can trade RPM for torque but the smallest motors are kind of a waste unless space is an issue or very high RPM are important. How are you accomplishing PID control? I have thought about using Arduino and a digital potentiometer to control an SCR for a sort of homemade setup but it hasn't been enough of a priority for me to mess with.
@@dazecars I am using Arduino for PID control. Rectifying mains, then taking PWM generated by Arduino and modulating DC with MOSFET. Motor has an encoder on the shaft and providing feedback to the Arduino that calculating PID constant speed function. That part is done already, now I am adding some safety functionality - overcurrent protection, overspeed protection, temperature protection, soft start.
love your content! have learned a lot about treadmill motors, by question is, will these motors work in reverse as well as fwd?
almost all DC motrs will do forward and reverse th-cam.com/video/B1pj3N1J2vg/w-d-xo.html
Thanks
My pleasure