| 摘要 |
PCT No. PCT/JP79/00231 Sec. 371 Date May 5, 1980 Sec. 102(e) Date May 5, 1980 PCT Filed Aug. 31, 1979 PCT Pub. No. WO80/00609 PCT Pub. Date Apr. 3, 1980.This invention relates to a control circuit which controls combustion in a burner acting as a heat source of a hot-water boiler or a hot-air heater. More particularly, the present invention relates to a control circuit having a sequence which includes post-discharge such that electric discharge for ignition is still continued for a predetermined period of time, even after attainment of ignition. In a combustion control apparatus, when ignition is not attained within a predetermined safty period, the igniting operation is stopped by a safty timer for timing this safety period, thereby ensuring the safety. It is necessary to reliably discontinue the igniting operatin even when this safety timer is disabled. The present invention attains this object and ensures the safety with a reduced number of timers. That is, a timer for timing the post-discharge period is provided independently of the safety timer, these two timers starting their timing operations at the same time, so that the fuel valve can be cut off by an output from the post-discharge timer too in the event of failure of ignition.
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