Printer motor controller reverse-engineer (ish)


How it came out of my junk box

Back in college we salvaged and gutted an old roll around printer.  Inside were like a million magnetic clutches, a bunch of rods, belts, and gears, and some of these motors.  The motor is self contained with its own control board and the silkscreen is labeled but the chip returns no results when googled.  Here is how to make it move:


That blue capacitor was a guess at the value, it’s on the 24v line and the original fell off years ago


HL – High/Low? needs to be 5V

Lock – magnetic clutch? dunno, but it’s getting the complement of the clock signal

Clock – speed input speed control, 5v square wave (10-600hz)

S/S – start/stop? dunno, bogs down when pulled up or down, seems to speed up a bit when tied to clock

GND – logic ground

+5V – logic supply

G24 – motor ground

+24V – motor supply

The chip is labeled: HFENGINE / VG30DSP / 4CA8G and I had no luck locating it with google.  This is a functional implementation, but probably not optimal.  It was a crapshoot even trying the complement of the clock signal on some of the lines and it seems to be stable.



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