It can input non-stable alternating current and output adjustable voltage. Its minimum output voltage is 1.23V and the maximum output current is 3A. LM2596 contains fixed frequency oscillator (150KHz) and benchmark voltage stabilizer (1.23 V), and has perfect protection circuit, current limit, heat cut-off circuit and so on. This circuit has the advantages of high efficiency and low heat. It can make full use of the various idle transformers around you to make the stable voltage stable power supply.
The non-stationary AC voltage input of J1 was rectified by d1-d4, C1 and C2 filtered as the input voltage of LM2596 output the stable DC voltage from J2 through the LM2596. C3, C4 is the output filter capacitance. R2 and LED2 constitute the indicator circuit. LED1 is 8mm white LED. Its brightness can roughly indicate the output voltage. If the brightness is too bright, you can increase the resistance of R2 properly. L1 is a special inductance, which acts as an energy conversion. D5 is the Schottky diode, which plays a continuous role in the circuit. C5 interferes the circuit. The output voltage of R1 and W1 can be calculated by the following formula: Vo=1.23(1+W1/R1)