| Electronics > Beginners |
| 12vdc motor fwd/rev with photo transistor |
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| YankeePirate:
Two phototransistors (?5vdc) drive a 12vdc 3 amp motor fwd/rev using the circuit so when light is detected by one motor goes fwd, and other makes it go rev. I have begun buying parts shown. Are resistors and mosfet correct? |
| xvr:
This is will not work out. To drive motor you need to apply '+' and '-' for BOTH pins of motor. Your circuit can apply only '+', but this is not enough. |
| Infraviolet:
Probably better to built your system around a H-bridge chip (assuming the current needed in the motor isn't too high) like a TB6612FNG or the rather inefficient old L293D. Then use an opamp to monitor the phototransistor so as to detect light levels, put this through another op-amp acting as a comparator with hysteresis (op-amps usually come in multi op-amp packages, so you might as well slightly misuse one op-amp to be a comparator rather than get a dedicated comparator chip), then feed this signal to the h-bridge chip. You sound like a beginner, so you'll definitely find it easier to work with IC chips (like op-amps, varous logic gates, and h-bridges) than with discrete transistors or MOSFETs. |
| YankeePirate:
In this version I added 2 MOSFETs to handle Ground. Will that work? |
| YankeePirate:
Should I add a resistor to the ground leg or before the 2nd Gates leading to ground? |
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