Which would be a better motor

Discussion in 'The Projects Forum' started by mrel, Oct 24, 2010.

  1. mrel

    Thread Starter Active Member

    Jan 20, 2009
    I would like to build security camera setup where by camera can pan and Tilt using either a stepper motor OR Dc to pulse width modulator motor device to control dc motor .
    I am not sure if I need a dc to pulse width modulator motor device to use for a dc motor .
    Thank for infor
  2. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    Depends on what your objectives are. If you want to go to some specific, yet varying angular location, a stepper might be the choice. If you want to follow a joystick command, then a PWM might be useful. I've gone through the same process and in the end settled for a stepper because I wanted to perform stacked image analisys.

    If you google into the community that photographs astronomy, you'll find a huge amount of information.
  3. DonQ

    Active Member

    May 6, 2009
    I might suggest using the RC-servo for one main reason. You do not have to do anything with power electronics going this way. You just hook the motor directly to a power source and the control pin directly to your control signal. The RC-servo also has a built-in gear ratio, allowing a very small motor to control a relatively large load.

    With a stepper, you have to either have a stepper-motor driver circuit, or do the switching of the relatively high-current phases of the motor yourself. More transistors have been blown out trying to do this for the first time than anywhere else (except maybe switch-mode power supplies).

    The RC-servo is a ready-made solution. They come in a wide range of sizes. Just get one big enough. Too big will still work once loaded, too small won't.
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    I'll also chime in with R/C Servos. They are fairly advanced for the price. Depending on camera weight, there should be one that will handle the load.

    If starting with a bare stepper or gearhead DC motor, the feedback system to limit the camera extreme limit stops and pan/tilt speed would be rather complex.

    Were the cameras going to be controlled by a microcontroller, computer, discrete components, or a combination thereof?