description: LM3914 is an integrated circuit that controls 10 pin terminals to output different voltages according to input signals and drive different LEDs for analog display. It is also called 10-segment point/line voltage detection driver. It is widely used for analog signal voltage detection and DC voltage level indication. , a variety of flash alarms, stage music spotlights, power voltage indicators and so on. The above is part of the description information, detailed circuit analysis and production process see PDF document! SMOK Vape pen, SMOK wholesale, SMOK Factory Shenzhen Xcool Vapor Technology Co.,Ltd , http://www.xcoolvapor.com
The AC voltage regulator circuit fabricated by LM3914 is mainly shown by the power supply circuit, power supply indicating circuit, reference voltage forming circuit, input signal sampling circuit, output driving circuit, AC voltage regulating circuit, and AC voltage output.
Circuit composition
The power supply circuit is composed of a power transformer T1, a bridge rectifier diode VD1~VD4, a filter capacitor Cl, a LM7812 type three-terminal voltage regulator integrated circuit A1, and a filter capacitor C2.
The power indicating circuit is composed of a light emitting diode LED and a current limiting resistor R1.
The reference voltage forming circuit consists of the 7-pin, 8-pin internal unit of the LM3914, the 4-pin and 6-pin internal voltage dividers, and the 7-pin and 8-pin external resistors R2 and R3, and the adjustable potentiometers RP2 and RP3.
The input signal sampling circuit is composed of an adjustable potentiometer RP1 and a filter capacitor C3.
The output driver circuit consists of ten operational amplifiers in pin 1 and pin 18 to pin 10 of the LM3914.
The AC voltage regulation circuit is composed of a drive current limiting resistor R4~R13 and a bidirectional thyristor VSl~VS10.
The AC voltage output circuit is composed of an autotransformer T2 and an AC power output socket X.