Ok, so I have the DC servo motor shown in http://catalogue.techno-test.com/pr...001_USB_Analogue___Digital_Servo_Trainer.html powered at +-24 V and I am trying to control it with an arduino.
I have an intermediate circuit on a PCB where I do the necessary voltage transformations in order to have a velocity and position input to the arduino between 0 and 5V.
Then I use 2 PWM pins of the arduino in order to produce my control signal again with the help of my intermediate circuit. One of them is connected to a non-inverting amplifier and the other one is connected to an inverting-amplifier. This way I can produce both a positive and a negative control signal. This signal is then passed to a power amplifier in order to control the motor.
The problem is the following : When I produce a 6.6 V signal in the way described above, the motor starts spinning too fast. However, when instead of a PWM arduino pin I use the 3.3 V pin in order to produce the 6.6 V signal the motor is moving as fast as expected. The input current to the power amplifier is in both cases 70 uA. Any idea what is going wrong?
I have attached the schematic of the intermediate circuit.
The power amp is on a different board and it apparently works fine because it has no problem working with the feedback console that comes along with the mechanical unit.
I don't know if it matters, but this experiment was working while my circuit was still on the raster and it also worked the first time I tried it with the PCB, but it suddenly stopped working ever since.
I have an intermediate circuit on a PCB where I do the necessary voltage transformations in order to have a velocity and position input to the arduino between 0 and 5V.
Then I use 2 PWM pins of the arduino in order to produce my control signal again with the help of my intermediate circuit. One of them is connected to a non-inverting amplifier and the other one is connected to an inverting-amplifier. This way I can produce both a positive and a negative control signal. This signal is then passed to a power amplifier in order to control the motor.
The problem is the following : When I produce a 6.6 V signal in the way described above, the motor starts spinning too fast. However, when instead of a PWM arduino pin I use the 3.3 V pin in order to produce the 6.6 V signal the motor is moving as fast as expected. The input current to the power amplifier is in both cases 70 uA. Any idea what is going wrong?
I have attached the schematic of the intermediate circuit.
The power amp is on a different board and it apparently works fine because it has no problem working with the feedback console that comes along with the mechanical unit.
I don't know if it matters, but this experiment was working while my circuit was still on the raster and it also worked the first time I tried it with the PCB, but it suddenly stopped working ever since.
