| 摘要 |
PROBLEM TO BE SOLVED: To supply a current with which a temperature rise is suppressed to an external load to secure a stable operation and protect the external load. SOLUTION: A 1st drive current is applied to a relay coil la for a specified period only to close a relay contact 1b. The resistance value of an external load 2 is detected in accordance with a voltage and current generated in the external load 2 when the relay contact 1b is closed for the specified period only. A current value to be supplied to the external load 2 is determined in accordance with the detected resistance value and a 2nd drive current having a PWM waveform with a duty ratio corresponding to the determined current value is supplied to the relay coil 1a. |
