Dual power supply circuit
Some circuits required dual power for a better operation like a power amplifier, audio amplifier, or another power circuit. That circuits made for operating with dual supply input voltage.
Dual supply means- One terminal gives +ve. One terminal gives -ve and one is for ground.
Two terminals give +ve and -ve supply accordingly and the third is grounded,
For example If any circuit required 12v dual supply that means it needs three input – 1 is +12v 2 is -12v and 3 is Ground.
Here I am giving some circuit of dual power supply with regulated and non-regulated output.
• Center tapped transformer is best for dual power supply circuits. It Means primary (input)has 2 terminals and secondary (output) has 3 terminals.
Select the diode for rectifier as per ampere required. You can use readymade bridge rectifier IC which is available in the market with the different current ratings.
12v dual power supply Circuit (UnRegulated)
This is the general 12 V DC Dual power supply circuit. The output is not regulated of this circuit
The following circuit diagram gives regulated dual power output, Regulator ic is used in these circuits.
12v dual power Regulated supply circuit
Dual 15v Regulated power supply
9V dual Regulated power supply circuit
• 79xx ic is used to regulate the negative input voltage where as the 78xx ic is used for positive input dc voltage regulation.
• Capacitor value can be used between 1000uf to 4700uf
• The pin configuration of LM 78xx and LM79xx are not the same so careful when connecting.
• The minimum input voltage should be greater than 3 volts than the required output if you use regulator ic. But if not ic used in the circuit then the same voltage transformer used as output is required.