When we need to build an 18V DC power supply circuit for a transistor pre-tone control circuit that is a quality sound. We so should use a stable DC voltage regulator. There are many choices to choose.
In the past, we used the zener diode and transistor regulator circuit. It is quite okay.
But now we often use 7818 regulator ICs to build 18V stable DC power supply circuits. Because it is so well circuit. It is compared in mind look inside the 7818 chip has many transistors and others so it should run better with only one transistor and zener diode, really?
Sometimes we can assemble them on a breadboard. It is easy! When people love to use them, producers make them a lot. So, it is quite cheap.
Simple 18V DC power supply circuit
The IC-7818 or LM7818 or L7818 is a circuit’s key. It is a fixed DC voltage regulator IC that so popular. Since they have a low load regulation so low noise signal on our audio system.
The working principle
As we build this circuit put on the power amplifier. So The output terminal of the transformer is our AC voltage input. The proper AC input range from 18V to 22V.
You may use the 18VAC 1A transformer. It makes an output current of 1A.
Then, the AC voltage passes through a full-wave bridge rectifier (D1 through D4). They will rectify the AC into pulsating DC.
Next, the 1,000uF 35V- capacitor will filter a pulsating DC into the DC unregulated voltage. Which this voltage about 24V to 26V.
If the output current is not full to 1A. You may add one 1000uF 35V capacitor. It can keep more current.
This DC voltage will flow through the input of 3-terminal IC1. It will converter any DC voltage to stable +18 volts regulated.
The 470 uF 35V capacitor filter DC voltage to smooth better.
Now, we have the stable regulator of 18V DC power supply for a lot of application next times.
Although the IC has good circuit protection. We have to use the IC1 with a suitable heatsink because while it is working with the high current it so heats.
Parts list we need it
IC1: LM7818 or L7818, 18V voltage regulator IC
C1: 1000uF 35V, Electrolytic Capacitors
C2: 100uF 35V, Electrolytic Capacitors
D1: D4: 1N4007, 1000V 1A Silicon Diode
Pre-amplifier DC regulator circuit
If you need a power supply for a high quality Pr-amplifier circuit, using the L7818 is easier than using transistors.
We add C3, C4 capacitors to reduce noise from various electrical frequencies. C1 reduces noise while turning on/off the circuit. The LED1 is power-on display.
18V Dual DC Regulator circuit
Some circuit requires 18V dual power supply circuit or 3 terminal output (+18V, – 18V and Ground).
We can use IC7818 and IC7918 to do this power supply.
Also 18V DC power supply Circuits
See more many circuit ideas for you.
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I love electronics. I have been learning about them through creating simple electronic circuits or small projects. And now I am also having my children do the same. Nevertheless, I hope you found the experiences we shared on this site useful and fulfilling.
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