초록 ▼

The heater control apparatus comprises an exhaust gas sensor 6 for detecting an oxygen concentration in exhaust gases of an internal combustion engine, a heater 5 for heating this exhaust gas sensor 6 to a predetermined temperature, a power source including a battery 2 for supplying electric power t

The heater control apparatus comprises an exhaust gas sensor 6 for detecting an oxygen concentration in exhaust gases of an internal combustion engine, a heater 5 for heating this exhaust gas sensor 6 to a predetermined temperature, a power source including a battery 2 for supplying electric power to this heater 5 and a charging generator 4 for charging this battery 2, a switching element 19 inserted into a circuit for supplying electric power to the heater 5 from the power source, control means 12 for performing current-carrying control of the switching element 19 so as to maintain a temperature of the exhaust gas sensor 6 at a predetermined value, and an overvoltage detection element 28 for outputting an abnormal detection signal when a voltage of the power source exceeds a predetermined value, and it is constructed so that the switching element 19 is broken to stop the passage of current to the heater 5 by the abnormal detection signal of the overvoltage detection element 28 when a voltage of the charging generator 4 abnormally increases due to disconnection etc. of the battery 2 of the power source.

대표청구항 ▼

1. A heater control apparatus comprising:an exhaust gas sensor provided in an exhaust passageway of an internal combustion engine, the exhaust gas sensor for detecting an oxygen concentration in exhaust gases; a heater for heating the exhaust gas sensor to a predetermined temperature; a power source

1. A heater control apparatus comprising:an exhaust gas sensor provided in an exhaust passageway of an internal combustion engine, the exhaust gas sensor for detecting an oxygen concentration in exhaust gases; a heater for heating the exhaust gas sensor to a predetermined temperature; a power source including: a battery for supplying heating electric power to the heater; and a charging generator for charging the battery, a switching element inserted into a circuit for supplying electric power to the heater from the power source; a controller including a microcomputer for performing current-carrying control of the switching element to maintain a temperature of the exhaust gas sensor at a predetermined value; and an overvoltage detection element for outputting an abnormal detection signal when a voltage of the power source exceeds a predetermined value, wherein the switching element is interrupted to stop the passage of current to the heater by the abnormal detection signal of the overvoltage detection element when a voltage of the charging generator abnormally increases due to disconnection of the battery of the power source.