DC adjustable power supply with overcurrent protection using LM723 - Power Supply Circuits

Probe current voltage pin 420*4450 head diameter 5.0 over current current and voltage pin

MOS power IC full range

LC03-3.3 SOP8 TVS Static Protection 3.3V

DC adjustable power supply with overcurrent protection The main component of this power supply is a general-purpose voltage regulator integrated block, which contains a starting circuit, a constant current source, a reference voltage regulator, and an overcurrent protection circuit. With high-power adjustment tube, it can output 0~20 continuously adjustable stable voltage, the maximum output current can reach 2A, and it has over-current protection function. It can be used as maintenance power source for mobile phone and BP machine, and can also be used for battery charging. The circuit is shown in Figure 1. In normal use, the red and green LEDs flash simultaneously. Adjusting the potentiometer W allows the output voltage to be adjusted from 0 to 20. When the output appears overcurrent or short..

DC adjustable power supply with overcurrent protection The main component of this power supply is the general-purpose voltage regulator integrated block LM723, which contains the start circuit, constant current source, reference voltage regulator, and overcurrent protection circuit. With high-power adjustment tube, it can output 0~20 continuously adjustable stable voltage, the maximum output current can reach 2A, and it has over-current protection function. It can be used as maintenance power source for mobile phone and BP machine, and can also be used for battery charging.

The circuit is shown in Figure 1. In normal use, the red and green LEDs flash simultaneously. Adjusting the potentiometer W allows the output voltage to be adjusted from 0 to 20. When there is overcurrent or short circuit at the output end, the voltage drop across R1 is greater than 0.6V, Q3 and Q4 are turned on. At this time, the green light is off, D7 is turned on, and the LM723's foot voltage drops close to 0V, and the internal detection circuit operates. The pin output high voltage is 23V, which makes Q1 and Q2 cut off, so there is no voltage output, which plays a protective role. There is output only when the power is turned off after powering off. In order to ensure that the rated current of the regulating tube Q1 is not burnt out, a sufficiently large heat sink should be installed. The whole power supply can be used as a casing with a plastic box, and the front panel is equipped with an ammeter, a voltmeter, a switch, and an adjustment potentiometer. Output terminals and red-green LEDs. This circuit works as long as the components are good and can be debugged without debugging. Among them, Q1 is best to use imported C2819, 2N3395 and other high-power tubes, IC can use LM723, MC1723 and so on. The printed circuit is shown in Figure 2.