Integrated regulated power supply with continuously adjustable output voltage

This is an integrated voltage-stabilized power supply with continuously adjustable output voltage. The output voltage is continuously adjustable between 1.25 and 37V, and the maximum output current can reach 1.5A. The circuit is simple and very suitable for electronic enthusiasts to make by themselves. It can be used to power various small appliances. The
working principle

circuit diagram is shown in Figure 1. The output current of LM317 is 1.5A, and the output voltage can be continuously adjusted between 1.25 and 37V. Its output voltage is determined by two external resistors R1 and RP1. The voltage difference between the output end and the adjustment end is 1.25V. This voltage will generate a current of several milliamperes, which will pass through R1 and RP1 to the ground. The voltage divided on RP1 is added to the adjustment end. By changing RP1, the output voltage can be changed. Note that in order to obtain a stable output voltage, the current flowing through R1 is less than 3.5mA. The maximum power consumption of LM317 is 2W without a heat sink, and its maximum power consumption can reach 15W when a 200×200×4mm3 heat sink is added. VD1 is a protection diode to prevent the output of the regulator from being short-circuited and damaging the IC, and VD2 is used to prevent the input from being short-circuited and damaging the integrated circuit.
Component selection and production
The component list is shown in the table below.

After the welding is completed and checked, the machine can be used normally without debugging. However, when welding, please note that capacitor C2 should be close to the input end of the IC and C3 should be close to the output end of the IC, so as to better suppress the ripple.