Lead-acid battery charging LED emergency light circuit diagram

The working principle diagram of the circuit drawn based on the actual object is shown in Figure 5. The 220V AC mains power is stepped down by the capacitor and rectified by the diode to charge the lead-acid battery , and the red LED is used as a charging indicator. After charging, when using the button switch K, close the button switch K, which will first turn on the three colorful flashing LEDs, emitting a dreamy and unpredictable colorful light, adding some fun to life at night. Press the switch K again to turn off the colorful flashing LEDs, and then Pressing it again will turn on 24 high-brightness LEDs connected in parallel. Due to the large number, the lighting effect is very good.

When the lead-acid battery voltage is 4V, the measured operating current of the colored lights is about 60mA, and the high-brightness LED current reaches more than 600mA. Such a large current not only prevents the lighting time from being too long after each full charge, but also causes damage to the internal structure of the battery and shortens its service life. Therefore, a small-value current-limiting resistor must be connected in series to the high-brightness LED. When the test selected 1.2Ω, the operating current finally dropped to 320mA, and the brightness change was not obvious. Since the lamp has not been changed much, the modified circuit schematic is omitted.

Through the above analysis, it is found that most of the various LED light circuits sold on the market are too simple. Although the price is very cheap, it will still cause a waste of energy objectively. Only through some reasonable improvements can it not only retain its economical and portable advantages, but also Effectively improve safety and reliability of use.