I thought that I needed a bit more power for the cutter on my CNC router. So I ordered a 775 Spindle Motor
That needed a speed controller, and ebay had a flash PWM Motor Speed Controller with Digital Display and soft start https://www.ebay.co.uk/itm/DC-9-60V...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
All this needed a decent power supply - around 30V and at least 5A - probably 10A. But I didn't have one handy, so while waiting for a delivery I used a laptop power supply. Probably switch mode, claimed output 18.5V, 2.7A. I put it all together and turned it all on.
It started perfectly. The only problem was that as soon as I put a medium heavy load on the motor, the PWM cut out. I measured the amps - the motor was taking around 0.1A at no load, then as I loaded it up the speed controller cut out about 0.3A, measured at the motor. Immediately afterwards it reset, and I could start the motor again quite readily. But I could not operate at more than about 0.3A without the motor cutting out again.
At first I thought that the speed controller was faulty, or specified in Chinese amps. But then I noticed that when the motor cut out, the indicator light on the laptop supply blinked as well. Which made me think that the power supply ran out of juice, which is why the controller died.
Now I had thought that the laptop power supply would be good for at least 2A at 18.5V. That is well within the range of the PWM speed controller, and well below what the motor was drawing. But is there some kind of interaction between a Switch Mode suply and a PWM that I am unaware of? Or is something else happening here? Should I be measuring some other parameter to discover what is happening?
- Rated Voltage: 12V-36V
- 12V Load Current: 1.7A (starting current 2.2A)
- Stall Current: 4.7A
- Load Power: 20.4
That needed a speed controller, and ebay had a flash PWM Motor Speed Controller with Digital Display and soft start https://www.ebay.co.uk/itm/DC-9-60V...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
- DC 9-60V
- 12A
- 500W
All this needed a decent power supply - around 30V and at least 5A - probably 10A. But I didn't have one handy, so while waiting for a delivery I used a laptop power supply. Probably switch mode, claimed output 18.5V, 2.7A. I put it all together and turned it all on.
It started perfectly. The only problem was that as soon as I put a medium heavy load on the motor, the PWM cut out. I measured the amps - the motor was taking around 0.1A at no load, then as I loaded it up the speed controller cut out about 0.3A, measured at the motor. Immediately afterwards it reset, and I could start the motor again quite readily. But I could not operate at more than about 0.3A without the motor cutting out again.
At first I thought that the speed controller was faulty, or specified in Chinese amps. But then I noticed that when the motor cut out, the indicator light on the laptop supply blinked as well. Which made me think that the power supply ran out of juice, which is why the controller died.
Now I had thought that the laptop power supply would be good for at least 2A at 18.5V. That is well within the range of the PWM speed controller, and well below what the motor was drawing. But is there some kind of interaction between a Switch Mode suply and a PWM that I am unaware of? Or is something else happening here? Should I be measuring some other parameter to discover what is happening?