Dear folks,
I try to drive 2 high torque servo motors with 2 L293D, but encountered several problems. I'm hoping someone here has clues for me. Thanks in advance.
I hacked the servo motors so that they are now 2 geared DC motors that operate 4.5v~6v. The 2 L293D were piggybacked to provide the current needed. I wired the servos directly to 4.5V (3 AA batteries), they raised the heavy arms attached to them. I wired the servos and L293D (piggybacked) and provide L293D power and input signals directly from 6V and ground with a SMPS wall wart, they raised the heavy arms. So I think that the power source and L293D output are able to handle my servos.
Besides L293D, there are also an Op-amp (ua741), a 4011, a 4049, and a couple of pull-up resisters in my circuit. Anyway, here are my problems:
1. I used the 6v wall wart for motor power and 4 AA batteries for logic circuits. The op-amp output signal is "windowed" (output high is about 4v, low is about 1.5v). I learned that a poor SMPS can have terrible effect on op-amps. What better solutions do we have to remove the noise of a poor SMPS. (I have tried to put a capacitor between 6v to ground, not helping)
2. Gave up the wall wart for the time being, I used 2 6V (4 AAs) separately for motor power and logic circuit. The circuit works fine when motors are not attched. (6V/1xx mV output for motors from L293D). But when motors were attached, they stalled. Apparently, L293D is not providing as much juice "in my circuit". (Probably not enough current, since I got 6V/1xxmV output.)
3. I also noticed that my logic circuit voltage is dropped to about 4V instead of 6V even when I pulled off the 6V motor power. Why is my 6V battery drop voltage to 4V in my circuit? Is it the same reason causing my motor power providing not enough current?
I try to drive 2 high torque servo motors with 2 L293D, but encountered several problems. I'm hoping someone here has clues for me. Thanks in advance.
I hacked the servo motors so that they are now 2 geared DC motors that operate 4.5v~6v. The 2 L293D were piggybacked to provide the current needed. I wired the servos directly to 4.5V (3 AA batteries), they raised the heavy arms attached to them. I wired the servos and L293D (piggybacked) and provide L293D power and input signals directly from 6V and ground with a SMPS wall wart, they raised the heavy arms. So I think that the power source and L293D output are able to handle my servos.
Besides L293D, there are also an Op-amp (ua741), a 4011, a 4049, and a couple of pull-up resisters in my circuit. Anyway, here are my problems:
1. I used the 6v wall wart for motor power and 4 AA batteries for logic circuits. The op-amp output signal is "windowed" (output high is about 4v, low is about 1.5v). I learned that a poor SMPS can have terrible effect on op-amps. What better solutions do we have to remove the noise of a poor SMPS. (I have tried to put a capacitor between 6v to ground, not helping)
2. Gave up the wall wart for the time being, I used 2 6V (4 AAs) separately for motor power and logic circuit. The circuit works fine when motors are not attched. (6V/1xx mV output for motors from L293D). But when motors were attached, they stalled. Apparently, L293D is not providing as much juice "in my circuit". (Probably not enough current, since I got 6V/1xxmV output.)
3. I also noticed that my logic circuit voltage is dropped to about 4V instead of 6V even when I pulled off the 6V motor power. Why is my 6V battery drop voltage to 4V in my circuit? Is it the same reason causing my motor power providing not enough current?