Help about capacitors

Discussion in 'General Electronics Chat' started by emoy020, Oct 24, 2012.

  1. emoy020

    Thread Starter New Member

    Oct 23, 2012
    can someone discuss to me the differences and use of run capacitors and start capacitor..?
    can i use them in d motors???
  2. Bob T.


    Oct 22, 2012
    i know that a capacitor with a motor increases the speed and torque, thats because when the coil in the motor is opposing the magnet the capacitor discharges to repel or attract the magnet and cause rotation, and when it is discharges, while the motor is rotating it charger again, this can happen thousands of times in a second.
  3. PackratKing

    Well-Known Member

    Jul 13, 2008
    °I can never remember which direction this rule of thumb leans.....insofar as ac phase goes, they say " resistance lags, capacitance leads"
    The start coils on an AC capacitor-start motor - controlled by the centripetal switch, offer an additional field 90° apart from the run coils, to give the added oomph to get a static load moving. When the motor gets up to approx. 75% of rated rpm, the switch opens and kicks the capacitor / start coils out of the game.

    A permanent split-capacitor motor, as in ones employed in an air-conditioner condenser fan, the capacitor affects phase, to give more start torque.

    This from 8 years in HVAC / motor repair [ though not rewinding ] tho' give an old retired fossil slack for fading memory :D
    Hmmm... Memory..... use it or lose it :rolleyes:
    Last edited: Oct 24, 2012
  4. MrChips


    Oct 2, 2009
    Easy, just remember "ELI the ICE man".
    PackratKing likes this.
  5. emoy020

    Thread Starter New Member

    Oct 23, 2012
    sir whats ELI and ICE..?
  6. BillB3857

    AAC Fanatic!

    Feb 28, 2009
    ELI = Voltage leads Current (inductive), E=voltage, L=Inductance, I=Current

    ICE= Current leads Voltage (Capacive), I=Current, C=Capacitance, E=voltage

    The above represent the phase relationships in capacitive and inductive reactive circuits.

    In a pure resistive circuit, current and voltage are in phase.
    PackratKing likes this.