Circuit for controlling glow plug energization
First Claim
1. A circuit for controlling glow plug energization for use with a diesel engine having at least one glow plug energized by actuation of an ignition switch having an OFF position, an ON position for connecting said circuit to a power sources and an ST position for starting the diesel engine, said circuit comprising:
- a first circuit means for producing a simulation voltage signal with a level which changes substantially in accordance with the change of glow plug temperature upon glow plug energization and deenergization;
a second circuit means for generating a first reference voltage signal with a level which is determined in relation to a desired glow plug temperature and which is changed in magnitude in response to the change in the voltage of said power source and the temperature of the engine coolant, the magnitude of said reference voltage signal being changed inversely with changes in the voltage of said power source;
means for comparing the level of said simulation voltage signal with that of said first reference voltage signal; and
a switching means responsive to the resulting output of said comparing means for controlling the flow of current from said power source to the glow plug to energize the glow plug, whereby the glow plug is energized so as to be heated to said desired glow plug temperature.
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Accused Products
Abstract
A circuit for controlling glow plug energization for use with a diesel engine having at least one glow plug energized by actuation of an ignition switch. The circuit has a simulator for producing a simulation signal indicative of glow plug temperature, a generator for generating a reference signal with a level which is determined in relation to a desired glow plug temperature and which is changed in magnitude in response to the change in the voltage of said voltage source and the temperature of the engine coolant, and a switch responsive to the result of comparing the simulation signal with the reference signal for controlling the flow of the current from said power source to the glow plug to energize the glow plug, whereby the glow plug is energized so as to be heated to said desired glow plug temperature.
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Citations
10 Claims
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1. A circuit for controlling glow plug energization for use with a diesel engine having at least one glow plug energized by actuation of an ignition switch having an OFF position, an ON position for connecting said circuit to a power sources and an ST position for starting the diesel engine, said circuit comprising:
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a first circuit means for producing a simulation voltage signal with a level which changes substantially in accordance with the change of glow plug temperature upon glow plug energization and deenergization; a second circuit means for generating a first reference voltage signal with a level which is determined in relation to a desired glow plug temperature and which is changed in magnitude in response to the change in the voltage of said power source and the temperature of the engine coolant, the magnitude of said reference voltage signal being changed inversely with changes in the voltage of said power source; means for comparing the level of said simulation voltage signal with that of said first reference voltage signal; and a switching means responsive to the resulting output of said comparing means for controlling the flow of current from said power source to the glow plug to energize the glow plug, whereby the glow plug is energized so as to be heated to said desired glow plug temperature. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A circuit for controlling glow plug energization for use with a diesel engine having at least one glow plug energized by actuation of an ignition switch having an OFF position, an ON position for connecting said circuit to a power source and an ST position for starting the diesel engine, said circuit comprising:
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a first circuit means for producing a simulation voltage signal with a level which changes substantially in accordance with the change of glow plug temperature upon glow plug energization and deenergization; a second circuit means for generating a first reference voltage signal with a level which is determined in relation to a desired glow plug temperature and which is changed in magnitude in response to the change in the voltage of said voltage source and the temperature of the engine coolant; means for comparing the level of said simulation voltage signal with that of said first reference voltage signal; and a switching means responsive to the resulting output of said comparing means for controlling the flow of current from said power source to the glow plug to energize the glow plug, whereby the glow plug is energized so as to be heated to said desired glow plug temperature, wherein said second circuit has a generator for generating a second reference voltage whose level changes in response to the change in the voltage level of said power source, and a voltage divider which changes in dividing ratio in accordance with the coolant temperature and divides said second reference voltage to produce said first reference voltage signal. - View Dependent Claims (8)
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9. A circuit for controlling glow plug energization for use with a diesel engine having at least one glow plug energized by actuation of an ignition switch having an OFF position, an ON position for connecting said circuit to a power source and an ST position for starting the diesel engine, said circuit comprising:
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a first circuit means which includes a capacitor and produces a simulation voltage signal by charging/discharging said capacitor, the level of said simulation voltage signal being changed substantially in accordance with the change of glow plug temperature upon glow plug energization and deenergization; means for comparing the level of said simulating voltage signal with a reference voltage signal; a switching means responsive to the resulting output of said comparing means for controlling the flow of the current from said power source to the glow plug to energize the glow plug to heat the glow plug to the desired glow plug temperature; and a circuit means for applying a charging voltage of a predetermined level to said capacitor when said diesel engine is running to maintain a predetermined charge level for said capacitor corresponding to the temperature of said glow plug so that when said ignition switch is switched Off and then switched over to its ON position and said switching means is OFF, said glow plugs will not be overheated. - View Dependent Claims (10)
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Specification