| Electronics > Beginners |
| What this motor type? |
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| james_s:
Who is talking about reversing both? The schematic I see is only reversing the power to the armature. |
| Benta:
Yeah you're almost right, but not quite. What I see is short-circuiting the armature (schematic error). But using a double-pole relay would be simpler and safer. Who knows what's happening as the MCU boots? |
| Cos-Phi:
--- Quote from: james_s on November 14, 2018, 04:24:44 pm ---Who is talking about reversing both? The schematic I see is only reversing the power to the armature. --- End quote --- --- Quote from: Benta on November 14, 2018, 09:40:57 am ---Why do you want to reverse both armature and field? It's only necessary to reverse one to change direction. And you really need to use the tacho feedback, otherwise your speed control will be very unstable. --- End quote --- Yes, of course. I need changing the direction of rotation. i wrote a program for my uC that will run in 2 mode. Free running and speed-based mode. in the free-running mode, the user is only enter the direction (CW or CCW), and the speed can be adjusted by pressing button up and down. start point is 10% (by firing TRIAC delayed 9mS after my ZCD detected crossing position of AC Line input. my AC lIne period is 20mS). And then the speed of motor will be showed in the LCD Display. And, in the speed -based mode, user will enter the direction (CW or CCW) and the speed. and then,microcontroller will start and controll the motor rotation speed automatically. of course, both mode (free-running and Speed-based) maximal speed was set due to over speed protection. I was use the LM393 Comparator chip to convert sinewave tacho signal to TTL Level pulse, and then read by uC useing Timer0 module. on full power, i got 16.000 pulse every 1minut (may be it is refer to 16000RPM. because i have no data about the tacho). SO i was limit to 10.000 pulse / minut only. tnx cos-phi |
| perieanuo:
Don't reinvent the wheel,put triacs,pwm control on them if you want,triac for direction change.quick,easy to control. Envoyé de mon iPad en utilisant Tapatalk |
| Zero999:
--- Quote from: perieanuo on November 15, 2018, 04:01:05 pm ---Don't reinvent the wheel,put triacs,pwm control on them if you want,triac for direction change.quick,easy to control. Envoyé de mon iPad en utilisant Tapatalk --- End quote --- Using a TRIAC for direction change seems a bit odd. I'd be inclined to use the TRIAC for speed control and an old fashioned relay to change the direction. |
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