This is high temperature fire alarm circuit, when the temperature rise exceeds the limit, it will sound the siren rang out. It is easy to use with transistor circuit to detects heat. Then, a loud noise of the sirens with IC packages. How it works We uses the combination between Q1 (BC109), which is silicon NPN transistor and Q2 (AC188) which is PNP germanium transistor To detect heat in case of fire. Then, the siren will sound warning beeps. The collector lead of Q1 is connected with Base lead of Q2, while the collector lead of Q2 is connected with …
This is AC motor burn out protection causes of under voltage input. The principle is simple, it will check for voltage at all times. Normal voltage is 220V AC. If the voltage falls below a preset. Relay will not work and the LED is a warning. Can be set to cut no-off in the voltage during the 168-227V. As AC main in normal level, the relay will be connect to apply AC line to motor. And AC-line fall down lower than 10% of normal voltage the relay will cut of load at once. Until the voltage is restored to its …
This AC 220V siren circuit is a simple sirenthat use 220V AC as power supply. It is small size and use a piezo speaker cause use low power and saving. How it works This circuit is shown as Figure 1 which we use power source by reducing AC-voltage of 220 volts down by the resistors-R1, R2 ; the capacitor-C1 act as coupling AC-voltage. Secondly, the current will rectifier into DC voltage by diode bridge D1-D4. And there is C2 function to filter steady DC current. The some voltage will flow to emitter lead of Q5 and other will is sent …