小小定时提醒器

小小定时提醒器,portable timer

小小定时提醒器 作者：周海    定时提醒器的电路如图所示，主要由3部分电路组成：(1)定时充电电路；(2)主延时电路．它是利用CM0s集成电路具有输人阻抗高、输入电流小这个特点．用电容C2和电阻R2决定放电时间长短．维持反相器输人高电压；(3)音频振荡器电路。 使用时，打开电源开关，扬声器会呜叫一声，然后就不响了。经过20分钟左右的时间．扬声器再次长鸣，提醒您时间到了。如果想改变时间，可调整电容c2和电阻R2的数值。 google translate: Regular reminders of the circuit shown, the major part of the circuit by the three components: (1) time charging circuit; (2) the main delay circuit. It is the use of CM0s integrated circuits with high input impedance, input current is small this feature.Capacitor C2 and resiSTor R2 with the decision of discharge duration. Maintenance of high voltage inverter input; (3) audio oscillator circuit.
Used, turn the power switch, speaker will be Ming calls out, then do not ring. After 20 minutes of time. Speaker once again blew the time to remind you. If you want to change the time, adjustable capacitor, and resistor R2 c2 values.