Dual supply from single power supply

Dual supply from a single power supply - This is the only solution

A dual supply is used in some amplifiers and sub-woofer amplifiers. It's because such power supplies can handle heavy loads.

To convert a two terminal transformer output to a dual supply we need to make slight changes with the rectifier. Instead of a single bridge rectifier we need two bridge rectifiers.

To go ahead here we use to build a dual supply circuit. The parts used are:

• One 0 - 9 volt transformer, two secondary pins.
• 8 rectifier diodes.
• 2 Capacitors

Given below is a circuit on how to build a dual power supply from a single supply

Click the image for high resolution

So start by making 2 bridge rectifier using the diodes.

After that connect the two rectifiers together. Together means connect the positive output or the cathode point and the negative output or the anode points together.

Then connect the two capacitors. To make it simple, hold the rectifier upward as the cathode or positive side is at the top.

Watch this video on how to build a dual supply from a transformer that is not center tapped @electronicselectricalmalayalam.

Now connect the positive of the capacitor to the input point of the upper-side rectifier. Input point is where the transformer will be connected.

The Negative of the capacitor also should be connected to the next rectifier input point.

Now the circuit looks like this

Then it's time to connect the transformer.

Connect the two output pins of the transformer to the two input pins of the upper side rectifier.

Test your new dual supply

Use a multimeter to test your new dual supply. You must set the multimeter range to DC and check the two output points. First we can see the output Dc -8.4 volts.

Here you can see the output Dc +8.4 volts.

You can also check the load capacity by connecting a bulb and analyze the Dc output intensity.

The output is already Dc but, still you have to connect 2 filter capacitors across the minus and plus terminals.

You may be interested in reading and watching on how to get killer base from your amplifier or woofers.

Conclusion

If you really need a powerfull dual supply, then consider buying a center taped transformer. This is an option if any center tap transformer is not available for that specified voltage.