| 摘要 |
PROBLEM TO BE SOLVED: To provide a control circuit by which the sevice life of a relay contact point is lengthened. SOLUTION: In this circuit, a relay contact point 2 is connected in series to a resistance load 3, and a relay driving means 6 controlled by a microcomputer 8 is connected to the coil 4 side of its relay contact point 2, and is constituted so as to perform current-carrying control on the resistance load 3 by on/off of a relay by the microcomputer 8. In this case, a current-carrying rate of the resistance load 3 is determined by the ratio of on-time of its first time to off-time by the microcomputer 8, and is inputted by a time measuring means 12 by a commercial frequency, and the sum of on-time of first time and off-time is set in constant time by control by the microcomputer 8, and this time is set in odd number times one/(two×a commercial frequency) second, and on- time is also set in odd number times one/ (two×a commercial frequency) second.
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