| 摘要 |
PROBLEM TO BE SOLVED: To provide a relay drive device capable of suppressing heat generation of a relay.SOLUTION: A relay drive circuit comprises: a transistor 156 operating depending on a DC power supply voltage from a DC-DC converter; a Zener diode 161 connected with an output terminal of the transistor 156; a transistor 159 operated by a Zener current; and a relay 20 whose relay coil 21 is connected with a pair of relay output terminals consisting of output terminals of the transistors 156 and 159. When an output voltage between the relay output terminals becomes larger than a predetermined value defined by the Zener diode 161 and the transistor 159, the transistors 159 and 158 are operated to adjust an output voltage of the transistor 156, and thereby, to keep the output voltage between the relay output terminals at the predetermined value. |
