| ??? 12/09/11 21:20 Modified: 12/09/11 23:56 Read: times Msg Score: +1 +1 Good Answer/Helpful |
#185057 - Controlling Speed Responding to: ???'s previous message |
Andy Neil said:
Kai Klaas said:
I think he means to set the speed by PWM, not to control it. But still, PWM only sets the power - it does not directly set the speed. Andy has a good point. Yes, you can setup the motor to receive a PWM drive at a certain duty cycle and the motor will go to a particular speed. Change the duty cycle and the speed will increase or decrease accordingly. However if the load on the motor is not constant then the speed attained will be dependant on the amount of the load, amount of friction in the system, the duty cycle and the supplied voltage. In the scenario of actually "controlling the speed" of the motor it would be necessary to add a tachometer to the motor where the control system can then read the actual speed. It would then compare the detected speed to the desired speed and then control the generated PWM signal in a servo manner to bring the speed to within the expected range. Michael Karas |
| Topic | Author | Date |
| speed control of 12v dc motor | 01/01/70 00:00 | |
| 01/01/70 00:00 | ||
| That doesn't make sense! | 01/01/70 00:00 | |
| Which Motor ? | 01/01/70 00:00 | |
| RE: Which Motor ? | 01/01/70 00:00 | |
| reply | 01/01/70 00:00 | |
| I suppose you mean... | 01/01/70 00:00 | |
| RTFM | 01/01/70 00:00 | |
| PWM is done via the enable input | 01/01/70 00:00 | |
| PWM != speed control | 01/01/70 00:00 | |
| Setting speed... | 01/01/70 00:00 | |
| But still... | 01/01/70 00:00 | |
| Controlling Speed | 01/01/70 00:00 | |
| Analogy | 01/01/70 00:00 | |
Direction and Speed Control | 01/01/70 00:00 |