Constant current self-stop 6-24v charger principle - Power Circuit - Circuit Diagram

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

MOS power IC full range

Photocoupler

The simple charger described in this article can automatically charge the battery below 24V, the maximum charging current can reach 2.5A, and it has constant current charging and full self-stop function.

Figure 4-9 shows the schematic diagram of the automatic charger. The 220V mains voltage is stepped down by the transformer T to obtain the secondary voltage U2. The VD1~VD4 format rectifies and outputs the DC ripple voltage. The positive A point passes through the relay normally closed contacts K1-2, R4, ammeter PA, VT1, and passes through the battery GB. VT2 to the negative B point to charge GB, adjust the size of RP1, that is, adjust the base potential of VT1, VT2, thereby adjusting the Icb of VT2, that is, the charging current. Since the battery terminal voltage can reflect its charging condition, the battery with a nominal voltage of 12V is taken as an example. When the battery voltage rises to (12/2)*2.5=15V, the VT3 is saturated and the K1 is electrically connected. The closed contact K1-2 is turned off, the charging circuit is cut off, and the charger stops charging. Adjust RP2 to set the upper limit of the battery full self-stop.