The proposed scheme is based on the power supply standard application LM338 IC. The circuit is equipped with precise multiturn potentiometer.
Adjustable universal power supply to the LM338
Power supply specifications
- output voltage range: 1,5 … 32 AT
- Input voltage range: to 24 VAC (35 DC)
- maximum output current: 3 BUT
- built-in protection against overload and short-circuit
- input rectifier
circuit Description
Schematic diagram of the power supply shown in Figure 1.
rice. 1
Apparatus stabilizer circuit was completed bridge rectifier and input filter capacitor voltage. Circuit protection devices comprises LM338, which prevent its overheating and damage the output transistor of the short-circuit. LED1 LED indicates the presence of voltage on the power supply output. The output voltage is determined using a multi-turn precision potentiometer P1. maximum voltage, applied to the input of the module, should not exceed 24 VAC.
The printed circuit board power supply is shown in Figure 2.
rice. 2
The sample is collected on a small circuit board. Assembling typical and should not cause any problems. The power supply unit does not require any configuration operations and is ready for operation immediately after connection of the input voltage.
details
Resistors:
- P1:……..5k (multi-turn potentiometer)
- R2……..220 ohm
- R3:…….2,2 k
Capacitors:
- C1, C2:………1000 uF / 50 AT
- C3, C4:…..….100 NF (indicated 104)
- C5: …………..10 uF / 63 AT!
semiconductor components:
- D1, D2: ………….1N4007
- U1: …..……… LM338
- B1: ….……….. bridge rectifier