This is an Active buzzer is present inside with shock source, so as long as the electricity will call 2 Program control convenient, single chip microcomputer a high and low level can make the sound, and the passive buzzer is can not do.
The µPD4723 is a high-breakdown voltage silicon gate CMOS line driver/receiver based on the EIA/TIA-232-E standard. The internal DC/DC converter can switch between multiple voltages, allowing it to operate with a single +3.3 V or +5 V power supply.
The 2N6027 Programmable Unijunction Transistor is designed to enable the engineer to “program’’ unijunction characteristics such as RBB, η, IV, and IP by merely selecting two resistor values.