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Symmetrical Power Supply from NonCT Transformer

Symmetrical Power Supply from NonCT Transformer

As a technician and hobbyists, we are often faced with the problem of for the need the type of a voltage, where we had just the kind of asymmetric (+ and 0 V) while needs symmetrical (+, - and 0 V).

From the many circuits that I know, usually electronics friends make the power supply circuit from AC voltage asymmetric (NonCT) become a symmetrical voltage (+, 0, -) use IC L165 as the primary phase voltage convert so that it can be processed / in a split to 3 output voltages. But working the IC was very hard to need a large heatsink.  However, on this occasion, I will share changer circuit a voltage to be symmetrical with utilizing asymmetric Capacitors, Diodes, Zener Diodes, and Transistors. For a circuit schematic can be seen below,

Circuit Diagram
Circuit Diagram Power Supply + 0 - from NonCT transformer

Circuit and PCB Design

PCB Design Power Supply
PCB and Component into assembling on PCB
Working Circuit:
In the circuit scheme above, the AC voltage input from 220V AC output step-down transformer, where the output voltage of the transformer of 14.8V AC.

Stepdown Transformer Output Voltage

0V AC voltage direct entry into the diode and 14.8V AC enter directly to between series capacitors 1000uF/35V. AC voltage is processed by both of these components, so as to produce a DC voltage symmetrical (+,0,-) then filtered by two capacitors 1000uF/35V and 220uF/35V. At this point, I check the voltage around 76.6VDC +V and -V DC

Symmetrical power supply non regulating

The Voltage (+) and (-) 76.6VDC, for it symmetrical (+),(0V),(-) 33.3VDC. Then the voltage is lowered and regulated by using series transistor TIP31, TIP32, Zener12V, Rectifier Diode.

Voltage converter from AC NonCT to CT

I'm using Zener Diode 12V then the output becomes +12V 0 -12V DC. If you want the output voltage +15V 0 -15V, use Zener Diode 15V.

Symmetrical Regulated Power Supply

12V Regulated Power Supply CT

Just sharing to be together, if there are still less make a comment on the column below.

2 comments for "Symmetrical Power Supply from NonCT Transformer"

  1. what changes to be made for 45 v dc.

    Thanks in advance

  2. Can i replace the zener with ic regulator, 7815/7915?