The pressure gauge uses a pressure strain resistor Rx, which first converts the pressure into a resistor Rx, then turns the resistor into a digital pulse for counting and finally displays the pressure numerically. Silicon Controlled Rectifier (SCR)
Silicon Controlled Rectifier (SCR) is short for silicon controlled rectifier. SCRs are available in one-way, two-way, turn-off, and light control types. It has the advantages of small size, light weight, high efficiency, long life, easy control, etc. It is widely used in occasions such as controllable rectification, voltage regulation, inverter, and non-contact switches and other automatic control and high-power electric energy conversion.
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As shown in the figure, Rx is a pressure sensor, which together with 555 and so on constitutes a multivibrator. The oscillator period T is divided into T1 (the charging time of C is the time when 555 outputs a high level) and (the discharging time of C is also the time when 555 outputs a low level).