| 摘要 |
<p>A heat fire alarm device comprises a light-emitting diode, which anode via the first resistor is connected to first output of a transistor and anode of the first diode which cathode is connected to the first terminal of the first capacitor and via the second resistor to the first terminal of the third resistor and to base of the second transistor and first terminal of the second capacitor, which second terminal is connected to first terminal of fourth resistor and to cathode of the second diode which anode is connected to the first input terminal, and the second input terminal is connected to second terminals of the first capacitor and the third resistor, cathode of the first light-emitting diode and via the fifth resistor to the emitter of the second transistor which acts as a thermal sensor. The anode of the first light-emitting diode is connected to a collector of the third transistor and base of the fourth transistor, the cathode of the second light-emitting diode is connected to the first terminal of the sixth resistor, to collector of fourth transistor and to base of the third transistor, which emitter via the seventh resistor is connected to the anode of the second light-emitting diode and to the cathode of the second diode, and the second input terminal is connected to second terminal of the sixth resistor and via eighth resistor to the emitter of fourth transistor. Collector of fourth transistor is connected to emitter of first transistor which base is connected to cathode of third diode which anode is series-connected to second terminal of fourth resistor through fourth diode.</p> |
