Pyroelectric Fire Alarm System Diagram.
The front end of the circuit contains a sensitive signal amplifier constructed close to IC1 (CA3130). It delivers a high output when temperature near the piezo component raises. IC CA3130 is really a CMOS operational amplifier with gate protected p-channel MOSFETs inside the inputs. It has high speed of operation and low input current specifications. There are certainly two inputs-the non-inverting input (pin 3) connected to the piezo component via diode D7 (OA71) that carries the voltage signal from the piezo component and the inverting input (pin 2) that gets a preset voltage through VR1.
In the electrical sector, a schematic diagram is usually used to describe the design or model of equipment. Schematic diagrams are usually utilized for the maintenance and repair of electronic and electromechanical devices / units. Original schematics were made by hand, using standardized templates or pre-printed adhesive symbols, but nowadays Electrical CAD computer software is often used.
In electronic design automation, until the 1980s schematics were virtually the only formal representation for circuits. More lately, using the progress of computer system technology, other representations were introduced and specialized computer languages were developed, because with the explosive development of the complexity of electronic circuits, classic schematics are getting less practical. As an example, hardware description languages are indispensable for contemporary digital circuit design.