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.
This relay module is 5V active low. It is a single channel relay interface board, which can be controlled directly by a wide range of microcontrollers such as Arduino, AVR, PIC, ARM, PLC, etc.
The 2SK3451, 2SK-3451, K3451, 3451 is a Transistor MOSFET N-Channel Silicon 600V 13A 80W 3-Pins (3+tab) TO-220F In The FET Transistors, MOSFETs Category. Check Part Details, Parametric And Specifications.
The DC5V 2 Channels Relay Module is similar to the 4-channel version but with two relay channels. It is suitable for projects requiring the control of two separate high-power devices, providing a reliable interface between microcontrollers.