Zero-Fired Power Supplies

Similar in operation to the phase angle controlled SCR power supply, zero fired power supplies use SCRs to vary the power to the load.  However instead of varying the firing angle to reduce the RMS voltage, zero fire supplies use a time basis to vary power.  Since the waveform is always fully sinusoidal the resultant power factor is much higher.  Due to advances in SCR controller technology, these power supplies may be transformer coupled.


  • Output command via 4-20mA, 1-5V, or other custom range
  • Current limiting available for loads that have low resistance at start up
  • NEMA 1 or 3R Enclosure
  • Output voltage and current feedback optional