Repeater reset circuit diagram

This reset circuit is divided into power-on reset and power-on reset.

Power-on reset: When the power is turned on, the status in the CPU before the last shutdown is cleared to ground; Power-on reset: When the power is turned on, the movement switch is closed and the signal in the CPU is cleared to ground again immediately before the whole machine starts working. zero. This machine resets with low level reset and high level hold.

Power-on reset: When the power supply is turned on, the 6V voltage is limited by R102 to charge the C104 capacitor (according to the principle that the voltage at both ends of the capacitor cannot change suddenly due to the characteristics of the capacitor), causing T2 to conduct instantly and clearing the signal in the CPU to ground.

Power-on reset: Press the movement key and the voltage limits the current through R15, providing a bias voltage to the base of T8, turning T8 on, and outputting the voltage DVCC. The DVCC voltage limits the current through R13 to charge the C12 capacitor (according to the capacitor characteristics, the voltage across the capacitor (the principle of non-mutation), provide a bias voltage to the base of T2 to instantly turn on T2, clear the standby state signal in the CPU to ground, and make the machine enter the playback state, as shown in the figure below.