hafrse
Full Member level 3
Hello,
I have a circuit that controls the speed of capstan motor in a tape recorder, when powered on, the motor goes to the highest speed (unlocked) and then stabilizes to the correct selected speed after about 3-4 sec. If the power is powered +8v at pin 1 to the control circuit but the motor is disconnected and connected again, the servo locks directly to the correct speed.
its seems that only on power-on together when the motor is engaged when selected to Play (pin 9) connected to the motor.
Pin 1 +8V power
Pin 2 squarewave signal from the tachmeter
Pin 3 controls the speed by 4 capacitors, one for each speed, and then to GND
Pin 4,5 GND
Pin 6 is used for max speed through a diode and 47K resitor to +8v
Pin 7 not used
Pin 6 to indicator(not used)
Pin 9 to the motor
What can be wrong that causes the motor to spin very fast and then stabilizes when the circuit is powered by the +8v first time? as I explaned if I move the selector to other position where the motor is not engaged and engage the motor again (worm start , circuit is powered) , it locks directly
Thanks
I have a circuit that controls the speed of capstan motor in a tape recorder, when powered on, the motor goes to the highest speed (unlocked) and then stabilizes to the correct selected speed after about 3-4 sec. If the power is powered +8v at pin 1 to the control circuit but the motor is disconnected and connected again, the servo locks directly to the correct speed.
its seems that only on power-on together when the motor is engaged when selected to Play (pin 9) connected to the motor.
Pin 1 +8V power
Pin 2 squarewave signal from the tachmeter
Pin 3 controls the speed by 4 capacitors, one for each speed, and then to GND
Pin 4,5 GND
Pin 6 is used for max speed through a diode and 47K resitor to +8v
Pin 7 not used
Pin 6 to indicator(not used)
Pin 9 to the motor
What can be wrong that causes the motor to spin very fast and then stabilizes when the circuit is powered by the +8v first time? as I explaned if I move the selector to other position where the motor is not engaged and engage the motor again (worm start , circuit is powered) , it locks directly
Thanks