Homemade adjustable voltage regulated power supply for electric vehicles

Maintenance of controllers and chargers requires various DC power supplies. Figure 1 is a multi-purpose adjustable voltage-regulated power supply. The power supply is divided into two parts. The upper half is a bridge rectifier with capacitor filtering and no voltage regulation. The lower half is a bridge rectifier with capacitor filtering and an adjustable three-terminal voltage regulator to form an adjustable voltage-regulated power supply. Flexible combinations can meet various needs. For example, to detect the Hall speed control knob, only the adjustable voltage-regulated power supply part is used: to debug the undervoltage protection of the 36V brushed controller, the two power supplies are used in series.

Notes when using:
1. When testing the Hall device, only use the lower half of the power supply.
2. When adjusting the controller, connect the upper and lower power supplies in series.
3. The adjustable three-terminal voltage regulator should be equipped with a heat sink.
4. The maximum current can reach 1.5A.

Figure 2 connects the above power supplies in series to become a 25V~45V adjustable power supply. It is used to debug the battery undervoltage protection of the 36V brush controller. When using, adjust the DC voltage to 40V according to Figure 2, adjust the push-pull potentiometer to make the bulb just light up, then adjust RP to slowly reduce the voltage of the voltage regulator VAD, pay attention to the corresponding voltage when the bulb goes out, which is the undervoltage protection action value of the brush controller; adjust RP to slowly increase the voltage of the voltage regulator VAD, pay attention to the corresponding voltage when the bulb lights up again. This is the undervoltage protection recovery value of the brush controller. The recommended action value is 31.5V and the recovery value is 33V. If it is not within this range, change the resistance value of the corresponding resistor inside the controller and repeat the test.