The electronic buzzer buzzer is an integrated structure, using the DC voltage power supply, are widely used in computers, printers, copiers, alarm, electronic toys, automotive electronic equipment, telephones, timers and other electronic products for sound device. Buzzer is divided into two types of piezoelectric buzzer and electromagnetic buzzer. Buzzer in the circuit with the letter "H" or "HA" (old standard with "FM", "ZZG", "LB", "JD", etc.).