YesTripolarSwitch the circuitIn the design, the triode is not only widely used as a signal amplifier, but also displays unique switches. Unlike a mechanical node switch, the working method of a triode switch is based on current control between its base poles, ccds and transmitter poles. When the input voltage is low, the tripolar tube is cut-off (cutoff), the total electrode is zero, and there is no current flow between the base pole and the launching pole, thus achieving a switch break. At this point, if the tripolar tube is to be saturated (saturation), i. E., the closed state of the switch, vin needs to be sufficiently high to provide sufficient base-polar currents to allow a significant increase in the total electrode current, close to the power voltage vcc. When designed, vin is usually selected to be less than 0. 6 volts, or even lower, to ensure that triodes remain closed. In order to achieve guidance, i. E. Shut down, there is a strong need for short circuits for ccds and launches, which means that vin needs to reach a threshold sufficient to allow triodes to enter saturated zones. The relationship between the ic and the ib of the electrostatic current in saturation follows the beta value (the direct current gain), which may differ from the exchange beta value. By formula (1), we can calculate the minimum base pole current ib that meets saturation conditions, while cell voltage vin can be calculated by formula (2), so long as vin is greater than or equal to that value, the triode will be channeled, the load of electrical resistance is subject to full power supply and the switch closed. In conclusion, the key to the design of tripolar switch circuits is the precise control of input voltage vin to achieve the transition of the tripolar tube between the cut-off and saturation states, thus effectively controlling the flow of electricity and completing the switch function. This process involves the understanding and application of the dynamic properties of the tripolar tube and is one of the basic course elements of electronic circuit design. Understanding and understanding of these fundamentals will help circuit engineers to design and optimize the various switches flexibly。
