| 摘要 |
<p>A timer circuit for the alarm of a cooking completion using an ordinary analog timer IC generates a short sound when the operation of a timer 1 (555 timer IC) starts, continuously generates intermittent sounds when the set time of the timer 1 elapses, and notifies a battery replacement time by having a composition in which: an output end of the timer 1 having a circuit of a stable mode is connected to a base of a TR by passing through a resistance (R); a condenser (C) is connected to a part between a GND and a part where the resistance (R) and the base of the TR are connected; a collector of the TR is connected to a VCC; an emitter of the TR is connected to a threshold of a timer 2 (555 timer IC) formed in an unstable mode; an LED and a buzzer including an oscillation circuit inside are driven by controlling another TR by an output end voltage of the timer 2; and a power switch (S/W), a temperature switch (T/S), and a battery are connected in series. The timer circuit for the alarm of a cooking completion has a composition in which an output of the timer 1 passes through a part where diodes (D) and a resistance are connected in parallel and is connected to a TR base.</p> |
