Controlling 0-60VDC from 0-5VDC

Discussion in 'General Electronics Chat' started by chuzkin, Apr 22, 2014.

  1. chuzkin

    Thread Starter New Member

    May 21, 2012
    Hi friends.

    I think i should give more detailed information.
    What I need is to uso a PIC microcontroller, so using 2 push-buttons, I can increase / decrease the voltage level from 0VDC to 60VDC. The PIC output range is 0-5VDC, so I need an interface to convert this signal to 0-60VDC.
    Current output needed 2.5 or 3A. Load is a magnet, with the following voltage/current measured:

    40V - 2.08A
    34.8V - 1.85A
    30.3V - 1.26A
    24.5V - 0.69A
    18.4V - 0.12A
    17V - 0.01A

    The idea is to replace actual boards to get 50 or 60VDC in order to achieve a stronger magnetic force.


    Best regards.
  2. wayneh


    Sep 9, 2010
    What sort of power supply do you have to supply the ~80W required?

    You want each button press to increment voltage by some amount?

    Also, something is wrong with your data or your description: The current through a magnet coil should be proportional to voltage with a zero intercept. Why no current in your magnet with <17V ?

    My approach would be to pass the current through a low ohms shunt resistor in series with the coil and compare the ∆V across the shunt to the set point reference voltage given by the controller. Use an op amp and power transistors to close the feedback loop.
    Last edited: Apr 22, 2014
  3. crutschow


    Mar 14, 2008
    For that value of current and voltage I would use PWM from the PIC to control a MOSFET which would vary the current with low losses.
  4. wayneh


    Sep 9, 2010
    I was thinking of that but wouldn't you then also need a low pass filter to avoid sending a square wave to a giant inductor? The OP's odd data also makes me wonder if this is more than a simple coil, and might have electronics on board.