analog control

  1. U

    Help with circuit of laser diode driver

    Hello. I restored a driver circuit for the laser diode using driver's PCB and Diptrace. Laser is Thorlabs S1FC635. I have some questions about circuit. I attached some pictures of this circuit. 1)I would like to understand role of the U2.3. "U2.3In-" is signal from drain of Q2.2. When I press...
  2. busevaran

    Trying to control a motor speed with a PID circuit.

    Hi everyone! I'm Buse. I'm trying to control a motor speed for a personal project. You can find the schematic of the circuit I found on a book. This circuit works with only the PID parts contrcuted. My problem start when I add the other parts. For example, U1 opamp (top left) is supposed to...