Saturday, December 27, 2014

Circuit Schematic Variable / Adjustable DC Power Supply 1.2V – 25V using LM338K

Eltronicschool. - Here is the circuit schematic of variable or adjustable DC power supply 1.2V until 25V special for you. In here you can build by your self variable power supply easily using circuit schematic like in figure 1 below to adjust your power supply 1.2V DC until 25V DC. This main component to do this work is LM338K.

According the original article from circuitdiagram said that the circuit uses IC LM338K as the voltage regulator, so we will get the stable and regulated output. The regulator IC LM338K provides 5A output current max, and the voltage from 1.2 to 32V, it also featured the integrated thermal and short-circuit protection. Maximum voltage at input and output of the regulator is 35V.

Circuit Schematic

Figure 1. Circuit Schematic Variable / Adjustable DC Power Supply 1.2V – 25V using LM338K  (Source: Circuitdiagram)

Component List
  1. Transformer with 0 until 24 VAC
  2. Capacitors (See C1, C2, C3, C4, C5)
  3. Resistors (See R1, R2, and R3)
  4. Diode IN 4007
  5. Bridge Diode (See GR1)
  6. IC LM338K


Circuit schematic like in figure 1 above is Circuit Schematic Variable / Adjustable DC Power Supply 1.2V – 25V using LM338K. The transformer current value depends your needs. For example, if you need 120W power output then you’ll need 5A transformer. 5A x 24V (full power) will give you 120W output power. Since this power supply circuit described to give us 1.2-25V DC output, then you must have transformer with 24V AC output.

For the diode, you have the choices whether use 4 diodes of single bridge diode. If you are have plan to use the PCB design in this post, then you have to use bridge diode. The value of diode is depend on the current value of transformer. For the example, if the circuit uses 3A transformer the you must use minimum 3A diode. And you can see more the PCB design and others using link source below.

Link Source:

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