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thinkl33t / CAMM3-SMOOTHIE

Adaptor to connect an old Roland CAMM3 CNC machine to a smoothieboard.
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Motor Speed Control - Clone BA6302A Circuit? #1

Open thinkl33t opened 10 years ago

thinkl33t commented 10 years ago

FV is calculated from a pulse chain on the spindle encoder using the following circuit: ea6302

https://groups.yahoo.com/neo/groups/CAMM-3/conversations/messages/361 describes how this voltage is used - if the voltage is higher than the potentiometer, the speed is decreased, if its lower, its increased.

This means we should be able to control the spindle speed from the smoothie by reading REVOLUTION and adjusting FV to the spindle speed we want! Side effects would be that the speed control display wont work though, unless we can design a complete replacement triac board, or feed the speed display with a pulse chain for the actual speed. (probably easy to do from a PWM generator pin).

thinkl33t commented 10 years ago

If we leave the original FV from the counter board, but intercept REVOLUTION somewhere, we can send whatever voltage we want to FV on the motor driver board, and be able to tell what the actual RPM is.

Maybe use a digipot pin, using an opamp to shift the 0v - 3v3 to 0v - 12v.

thinkl33t commented 10 years ago

Chip is a BA6302A - VCR motor speed controller! http://pdf.datasheetcatalog.com/datasheets/70/233658_DS.pdf

Cinezaster commented 9 years ago

Hi thinkl33t, have you figured out a solution for your problem with the speed controller? I'm doing a rebuild of a CAMM-3 to, but with the tinyG-board. Just like you stuck with the speed controller.