Charger circuit

The circuit shown can be used as a DC
power supply for a semiconductor radio and can also be used to charge dry batteries .
    The circuit shown in Figure 1-19 outputs the rectified pulsating
current from socket XS1 to charge the dry battery. When the switch Sl is set to position 1, it charges
the dry battery When it is set to 2, 4, and 5, it can charge the dry battery No. 2 respectively. , No. 4 and No. 5 dry batteries
are charged. When the switch is placed in the test position,
the voltage of the dry battery before and after charging can be judged based on the brightness of the indicator light. You can also connect a meter
to test the battery voltage before and after charging.
The rectified and filtered 6V DC voltage can be output from socket XS2 for use in semiconductor radios.
    Before charging, the dry battery must be visually inspected. The zinc cylinder of the dry battery should be intact, the electric paste is not dry, and the battery voltage should not be lower than 0. 9V.
Such dry batteries can be recharged. The charging current is preferably pulsating, so the effect is good and the battery regeneration rate is also high. The charging voltage during charging
should be 10% higher than the rated voltage of the battery being charged. The positive pole of the charging voltage is connected to the positive pole of the battery, and the negative pole is connected to the negative pole.
    The charging current cannot be too large, usually about 100mA for No. 1 dry batteries, about 70mA for No. 2 dry batteries,
about 40mA for No. 4 dry batteries, and about 30mA for No. 5 dry batteries. Generally speaking, the charging current is smaller, the charging time is longer, and the dry battery will last longer after charging
. If the charging current is too high and the battery is charged very quickly, it will easily cause the battery to heat up and the recovery rate will be low.
    The resistors RJ-R4 in the circuit diagram are mainly used to adjust the charging current and can be approximated. For example, the product is 30n, R2 is 45fl, the horse is
600, and R is 120S1.
    The transformer can be a commercially available electric bell transformer, or it can be self-wound. The secondary side can use 6.3V or 8V. LC is a low-frequency choke.
It uses an iron core with a cross-sectional size of 3. 5mm × 5.5mm and winds 600 to 800 turns of enameled wire with a wire diameter of 0.15mm. S2 is the power switch.
After it is turned on, the indicator light lights up to indicate that the power is on.