Basic introduction of low voltage / high current delay circuit

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This circuit consists of four voltage comparators of LM339 (the voltage comparator is a circuit that discriminates and compares the input signal, and is a basic unit circuit that constitutes a non-sinusoidal generation circuit. Commonly used voltage comparators have a single-limit comparator, hysteretic comparison , window comparator, tri-state voltage comparator, etc.) used to generate time delay and control at low voltage and high current output. Comparator's three parallel wired driving medium-power PNP transistors (PNP transistors are another type of transistor. It works like a NPN transistor, except that the majority carriers that move in the base region and amplify the signal are holes instead of The emission of the PNP transistor is positively biased, the voltage in the base region is lower than the voltage in the emitter region, and the collector is the majority of the carrier holes, and the voltage in the collector region is lower than that in the base region. The point is exactly the opposite of the inter-electrode potential of the NPN transistor.) This in turn drives the high current NPN transistor. After the fourth comparator is used to generate the time delay, the normally closed switch is turned on. Two resistors (36K and 62K) are used as voltage dividers for approximately two-thirds of the battery voltage of two-thirds of the (+) comparator input, or approximately two volts. After the delay time, turning on the switch will use a 50uF capacitor and a 100K variable resistor around a time constant, or about (50u * 100,000) = 5 seconds. The time can be reduced by adjusting the resistance to a lower value or using a smaller capacitor. A longer time can get a larger resistor or capacitor. To operate a higher voltage circuit, the 10 ohm resistor should be increased in proportion (4.5 volts = 15 ohms).