A light emitting diode (LED) control drive system for a sleep aid device, comprising:
- a universal series bus (USB) interface module, being configured to receive an external input voltage,
- a voltage regulator module, being connected to the USB interface module, comprising a conversion circuit, a filter circuit, and a storage battery, and configured to convert the external input voltage into a stable direct current voltage and charge the storage battery, so as to provide a stable power supply basis,
- a power management module, comprising a power control chip, wherein the power control chip is connected to the voltage regulator module and configured to control a working state of the conversion circuit and detect in real time a charging state of the storage battery, so as to guarantee the power supply stability by dynamic regulation,
- an LED lamp assembly, being provided with a plurality of sleep aid LEDs, and
- a constant current drive module, comprising a microcontroller and a dimming circuit, the microcontroller being connected to an infrared module and a touch module and configured to receive a user input command, wherein a control terminal of the dimming circuit is connected to the microcontroller and an output terminal of the dimming circuit is connected to the LED lamp assembly, and the dimming circuit is configured to control a brightness of the LED lamp assembly according to a command of the microcontroller based on the stable power supply basis, so as to avoid a voltage fluctuation impact,
- wherein the conversion circuit comprises an inductor, a first N-channel metal oxide semiconductor (MOS) transistor, a Schottky diode, a second P-channel MOS transistor, an NPN triode, a first resistor, an eighth resistor, a ninth resistor, an eleventh resistor, and a twelfth resistor,
- a source of the first N-channel MOS transistor is electrically connected to a VIN output terminal of the USB interface module, a drain of the first N-channel MOS transistor is electrically connected to a first terminal of the inductor and a cathode of the Schottky diode, respectively, and an anode of the Schottky diode is grounded;
- a gate of the first N-channel MOS transistor is electrically connected to a first terminal of the first resistor, a second terminal of the first resistor is electrically connected to the source of the first N-channel MOS transistor and configured to convert a high voltage outputted by the USB interface module into a low regulated voltage by regulating a duty cycle of a pulse width modulation (PWM) signal to supply power to a subsequent circuit,
- a second terminal of the inductor is electrically connected to a drain of the second P-channel MOS transistor and a first terminal of the twelfth resistor, and a second terminal of the twelfth resistor is grounded;
- a source of the second P-channel MOS transistor is electrically connected to an output terminal of the conversion circuit and a first terminal of the eighth resistor, a gate of the second P-channel MOS transistor is connected to a second terminal of the eighth resistor and a collector of the NPN triode, and
- a base of the NPN triode is electrically connected to a control terminal of the power management module through the ninth resistor;
- an emitter of the NPN triode is electrically connected to ground and the eleventh resistor is connected in series between the base and the emitter of the NPN triode and configured to eliminate a residual charge in a base region and suppress noise interference, so as to stabilize an on-off state of the NPN triode.