Connect with us

Adding Voltages?

Discussion in 'General Electronics Discussion' started by hpfiend, May 8, 2013.

Scroll to continue with content
  1. hpfiend

    hpfiend

    31
    0
    Feb 20, 2013
    Hello all!

    I am having a hard time understanding what is going on in this circuit I am probing.

    I have two wires hooked to a motor that have varied pwm output with hall sensor input.

    I T-tapped both wires in parallel and determined the following with my multimeter.

    The hall sensor goes from low signal to threshold point to high signal

    Wire A hooked to + on multimeter and - multimeter probe to ground shows 10 volts DC at low hall sensor signal and 60% duty cycle at about 1 kHz. As the hall sensor signal increases to threshold the voltage and duty cycle increase to 14 volts and 94%. At the threshold point the pwm turns off and the wire maintains 14 volts at the high hall sensor signal.

    Wire B is the inverse. Hooked to + on multimeter and - multimeter probe to ground shows steady 14 volts at low hall sensor signal. At hall sensor threshold the pwm turns on at 1kHz and 94% duty cycle. At increasing high hall sensor signal the voltage decreases from 14-10 volts DC and the duty cycle reduces to 60%.

    Now- what I can't figure out is if I hook Wire A to + and Wire B to - on my multimeter, I get the following.

    At low hall sensor signal I get negative -4 volts DC and the same 60% duty cycle. The duty cycle increases to 94% as it approaches hall sensor threshold and the voltage reduces to negative millivolts. At hall sensor threshold the circuit reverses polarity and shows positive millivolts and 6% duty cycle. At high hall sensor signal the duty cycle increases with positive voltage, I am assuming it will go to positive 4 volts and 40% thought I have not witnessed this yet.

    This should be obvious but it is escaping me....

    Thanks for any help you may be able to offer!!!!
     
  2. duke37

    duke37

    5,364
    769
    Jan 9, 2011
    I am sorry but I cannot understand your description. Please sketch a circuit diagram, scan it and post it.

    What is a Hall sensor threshold?
    What does the motor do?
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-