Circuit Project Electronic

In addition to providing an accurate input current limit, the
LT1618 can also be used to provide a regulated output
current for current-source applications. White LED drivers
are one such application for which the LT1618 is
ideally suited. With an input voltage range of 1.6V to 18V,
the LT1618 can provide LED drive from a variety of input
sources, including two [...]

The battery-charger circuit is designed to operate as a high power USB function. To be compliant with USB Specifications (Rev. 1.1), a high-power function must not draw more than 500 mA from the bus during normal operation. The LM3622 uses the 0.25 current-limit resistor R1 to set a 400 mA maximum charging current. This leaves [...]

This is a simple to build charger for single 3.7V lipo battery. The heart of the charger is TL431 shunt regulator that controls the incoming current. Charger comes with a convenient charging LED indicator. As charging current goes down so does the intensity of the LED.
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