Patent ID: 9672111
Date: 2017-06-06
CPC Classifications: G06F

Claim:
1. A load control backup signal generating circuit configured to supply a backup control signal to a switch of a load connected to an output of a control processor operating according to a program in a case that abnormality occurs in the control processor, the backup signal generating circuit comprising: a first input terminal configured to receive a constant period signal that is output periodically from the control processor when the control processor is normal; a constant period signal monitoring section configured to monitor a state of the constant period signal to identify whether a first length of time during which a high or low level state of the constant period signal continues is longer than a first predetermined time, and to output a first signal corresponding to a result of the identification by the constant period signal monitoring section; a backup signal output section configured to generate and output the backup control signal to the switch of the load when the output of the constant period signal monitoring section satisfies a first predetermined condition; a second input terminal configured to receive a control signal configured to control the switch of the load and that is output from the control processor to the switch of the load when the control processor is normal; and a control signal monitoring section configured to monitor a state of the control signal, to identify whether a second length of time during which an abnormal level state of the control signal continues is longer than a second predetermined time, and to output a second signal corresponding to a result of the identification by the control signal monitoring section, wherein the constant period signal is not output to the switch of the load.