Transformerless Power Supply (NI003E)

This power supply is indicated to power small loads up to 30 mA. The original output voltage is 6 V, given by the zener diode, but this diodes can be changed to source other voltages. Up to 12 V diodes can be used.




When powering the circuit from the 220/240 V AC Power line use a 470 nF capacitor for C1. Non-polarized types as polyester capacitors should be used. O capacitor C1 deve ser alterado para 470 nF se a rede for de 220 V. Figure Bellow shows the ripple displayed by the virtual oscilloscope of the Multsim




Observe the adjustments of the oscilloscope to correct dysplaying.

This circuit can also be simulated in the MultiSIM BLUE. See article MSB001E in the site.


To download the simulation files and Netlist - click here (

Circuit Bench