1.5V-25V DC Variable Power Supply

This is 1.5V-25V DC Variable Power Supply. The power supply use KR142EN14 or LM317 as regulator component. KR142EN14 or LM317 is capable to handle electric current up to 2A. You may use LT1083/84/85 to handle electric current of 7A/5A/3A. Resistor R9 is used as a current sensor to an ammeter.

electronic circuit diagram

Components list:
R1 : 4K3
R2 : 18K
R3 : 100
R4,R8 : 100K
R5 : 1K
R6 : 240
R7 : 4K7 ( Variable resistor )
R9 : 0.33 E
C2 : 0.1uF
C3 : 10000uF/40V
C4 : 100uF/25V
D1 : KY202
D2 : KD521
D3 : D311
D4 : KC147
T1 : KT814B
T3 : KT209
T4 : KT3102
IC1 : KR142EN14 (LM317)

Circuit source: 1.5V-25V power supply with preregulator

About Power Supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term of "power supply" is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy (e.g., mechanical, chemical, solar) to electrical energy.
A power supply may be implemented as a discrete, stand-alone device or as an integral device that is hardwired to its load. In the latter case, for example, low voltage DC power supplies are commonly integrated with their loads in devices such as computers and household electronics. More explanation about power supply can be found at wikipedia.org

This is the tutorial about "How to build an AC to DC power supply ". The video tutorial covers the basics of diodes, bridge rectifiers, and how to build simple unregulated AC to DC power supplies than can handle a few mA up to several Amps.

Watch the video: