Introduction
This circuit is used in danger places where the something can
cause huge damage in industries like power plants, boilers, heating elements
etc. These circuits are used to reset the alarm circuit when everything is
normal and the alarm starts ringing. This circuit is used in heavy industries.
Circuit Diagram
Explanation
This circuit consist of a pressure switch or a sensor to sense
the fire or other danger parameters to start alarm automatically when any
abnormal situation is created in the atmosphere to alert the workers or other
staff for human protection. When the pressure switch senses, the red indicator
is turned on and it also closes the circuit and the normally open magnetic
contactor then closes and give the supply to the alarm. The alarm starts giving
noise until we press the reset button. So, lets move on the alarm silencing
circuit.
The alarm silencing circuit is connected in parallel to the
pressure switch. It consists of the reset button and a relay which disconnects
the circuit from the line when we press the reset button.