| 摘要 |
PURPOSE:To allow an automatic restarting and continued stable operation as long as the noise does not persist in case of a 'running away' of a microcomputer by shutting off the fuel supply and restarting the operation from the beginning. CONSTITUTION:When a microcomputer 12 shows erratic operations while a heating appliance is burning due to external noises etc., the output signal of a first output port P1 stops its cyclic reversals to cause a switching circuit to go off. Therefore, a fuel pump 4 connected to its contact 11 stops its action to shut off the fuel. However, when the switching circuit 4 goes off, pulses having a certain length is fed to a reversal input terminal (-) of a comparator IC35. As the pulses have a potential at the L level, they assume a potential at the H level for a duration which corresponds to the width of the pulses, and the microcomputer 12 is reset thereupon. When the pulses are over, the output terminal of IC35 again assumes the potential at the L level, and the microcomputer 12 runs the predetermined program to restore a normal burning. |
