Dongguan Jiuqi Industrial Co.,Ltd.
Tel:+86-13873397666
E-mail:[email protected]

Contact us

Simple and practical ac steady current power charger

Simple and practical ac steady current power charger
Ac stable current power charger can start and stop charging when the power voltage reaches the rated value and give instructions. Programmable voltage regulator TL431 and Rl, R: constitute a voltage comparator. When the power supply starts to charge, the voltage of the power supply is low, TL431 stops, and the LED is not bright. At this time, the ac steady current composed of CRD and BG will continuously charge the power supply. When the power supply is charged to the rated value, TL431 is on, LED is emitting light, the transistor BG base voltage drops, diode D is cut off, and the circuit stops charging to the power supply. Another function of D is to prevent the reverse breakdown of c and e transistors when the supply voltage is high.

Dc power supply automatic charger
The charger shown in the figure also has charging status indication and protection circuit to prevent overcharging. Small capacitance, diode D: a D true constitute buck, current limit, rectifier circuit. Its output via diode D: a D, to charge the power supply, and in D. --D, 2 goes up. The iV voltage drop causes the led to emit light (green) as an indication of charging. Triode BG and potentiometer R constitute the protection circuit against overcharge. When the power supply is full, the BG saturation conduction will automatically cut off the charging current. At the same time, the red led will turn on because of the potential drop at point A, indicating the end of charging. R: is the discharge resistance. Its function is to discharge C after unplugging the power plug after charging, so as not to touch the plug by mistake.
The automatic charger can charge one to several power sources. The time-base circuit 555 is the core component of the circuit. It works not as a commonly used oscillator or bistable state, but as a comparator. The reference voltage of the two internal comparators is provided by the D true stable voltage. Potentiometers Wl and W2 provide a high and low limit of the sampling voltage. When the power supply E is not enough to charge, 555 because its (2) pin voltage is lower than (5) pin voltage, so the output end (3) pin output high level to charge E. When E is sufficient, 555 pin voltage is higher than 5 pin voltage, make (3 pin for low level, stop charging to the power supply E. R. Is the current limiting resistance. Select the resistance value according to the number of power nodes. D. Is used to prevent E from charging back to the time base 555 current.

It is a 12V constant voltage charger with three terminals of cwll7/217/317 which can be integrated into a voltage regulator to charge the battery. R really plays the role of current limiting, which is equivalent to increasing the internal resistance of the battery, reducing the charging rate at the initial stage of charging, and acting as overcurrent protection for the integrated block.
| release time:2019.10.25    Source:,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,
previous :Selection of PFC type, progression and working modenext:Dc power supply small automatic switching power supply