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+/-12V -> +/-5V Power unit




This is the voltage converter to get the voltage of 5V from the input voltage of 12V. I am using the 3 terminal voltage regulator for the voltage to be changed in this unit. As the regulator, LM317 is used for the positive voltage and LM337 is used for the negative voltage. The output current can make output in 1 A.
The point of this unit making is the radiator (the heatsink) of the regulator. The regulator becomes hot when outputting the 1 A electric current and when there is not a heatsink, the regulator breaks.
The merit of the regulator of this type is what little noise occurs and is cheap and there are few use parts. The demerit is the thing with the conversion efficiency which isn't good. When outputting from 12 V to 5 V, the efficiency (the output power/input power) is 42%. Recently, the switching regulator became cheap. The number of parts increases little but in case of more than 1 A power supply, you had better use the switching regulator with the good efficiency.