AVT1976 - Precise power supply with adjustable output voltage within range 1.5-32V/3A
The LM338 integrated circuit based power supply module. LM338 integrates all components of a high-quality voltage regulator. A precision multi-turn potentiometer is used to control the output voltage.
• Supply voltage within range 5-24V AC or 5-33V DC.
• Output voltage 1.5-32V DC.
• Maximum output current 3A.
• Built-in overload protection and short-circuit protection.
• PCB dimension: 52×63mm.
• Electronic Kit – soldering required.
The schematic of the power supply is shown in Figure 1. The standard stabilizer application is extended by a rectifier bridge, capacitive filtering input voltage and multi-turn potentiometer. The LM338 is protected against overheating and short-circuit. LED1 indicates that the power supply is on. The output voltage is adjusted by a multi-turn, precision potentiometer P1. The maximum voltage applied to the module input must not exceed 24 V AC.
Assembly and test
Assembly is typical. It starts with the smallest components and ends up with the biggest ones.
The power supply is ready to operate immediately after the input voltage is applied.
PR1: Precision potentiometer 5kΩ
C1, C2: 1000µF
C3, C4: 100nF
D1, D2: 1N4007 or similar
U1: LM338 LED1: LED diode
CON1, CON2: terminal block connection
Heatsink + fixing elements