throbscottle
Well-Known Member
Been having a clear out of old files, found this.
![motor-control.png motor-control.png](https://www.electro-tech-online.com/data/attachments/111/111514-c4f1c28cd4fcad5e956709eafaf8cc73.jpg)
I captured this bit of schematic when I dismantled an old money counting machine, years ago. It's the power supply to an induction motor which rotates the pick-up rotor. The motor is shown by L1, L2 and the circle. Triac D2 looks like a straightforward on/off, but what the heck is going on with Triac D1 + D3/D4?
Any ideas?
![motor-control.png motor-control.png](https://www.electro-tech-online.com/data/attachments/111/111514-c4f1c28cd4fcad5e956709eafaf8cc73.jpg)
I captured this bit of schematic when I dismantled an old money counting machine, years ago. It's the power supply to an induction motor which rotates the pick-up rotor. The motor is shown by L1, L2 and the circle. Triac D2 looks like a straightforward on/off, but what the heck is going on with Triac D1 + D3/D4?
Any ideas?