Basic introduction to low voltage/high current delay circuits

This circuit consists of four LM339 voltage comparators (voltage comparators are circuits that identify and compare input signals and are the basic unit circuits that make up non-sinusoidal wave generating circuits. Commonly used voltage comparators include single-limit comparators and hysteresis comparisons. comparator, window comparator, three-state voltage comparator, etc.) are used to generate time delays and control high current output at low voltage. The three parallel wires of the comparator drive a medium-sized power PNP transistor (a PNP transistor is another type of transistor. It works similarly to an NPN transistor, except that the majority carriers that move around the base and amplify the signal are holes instead of Electrons. The emitter junction of the PNP transistor must be forward biased, and the voltage of the base region is lower than that of the emitter region. If most carrier holes pass through the collector, the voltage of the collector region is lower than that of the base region. A point that is exactly the opposite of the interelectrode potential of the NPN transistor) which in turn drives the high current NPN transistor. The fourth comparator is used to generate a time delay after the normally closed switch opens. Two resistors (36K and 62K) act as a voltage divider for about two-thirds of the battery voltage and two-thirds of the (+) comparator input, or about 2 volts. After the delay time, opening the switch will revolve around a time constant using a 50uF capacitor and a 100K variable resistor, or approximately (50u * 100,000) = 5 seconds. The time can be reduced by adjusting the resistor to a lower value or using a smaller capacitor. A longer time can result in a larger resistor or capacitor. For operation on higher voltage circuits, the 10 ohm resistor should be increased proportionally, (4.5 volts = 15 ohms).