This is the high quality power supply to provide high current 3A. And
still adjust voltage in steps from 3V, 6V, 9V, 12V. adjust voltage is
continuous 1.25V to 20V. Using LM317T and 2N3055 are main parts so easy
to made and cheap.
Friends would known the power supply as well. Because you must use in
various circuit experiment. It originally had a small supply current,
when found projects that uses lot of current. Such as an audio
amplifier circuit so provide current is not enough.
This project can help you. Because of provide high current 3A. And still
adjust voltage in steps from 3V, 6V, 9V, 12V. adjust voltage is
continuous. And you do not have to worry. This creates a simple and
economical. If interested, please read on.
How it works
In the circuit below can be seen that, when opening switch S1 is current
through the transformer. To convert from 220V AC to 18V, then through
diode bridge rectifier BD1. But is a DC supply that still not smooth.
Then, a filter capacitor C1 serves electricity, out of BD1 to be more
smooth with the LED1 to show that power is supplied to already.
When the filter current is smooth on one order. The current will
through the regulator circuit that the main components are IC1(LM317T)
and Q1(2N3055).
-IC1 is the regulator IC number : LM317T.
-Q1 is power transistor NPN type number : 2N3055.
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