Device for detecting a transmissivity of a substance

A device for detecting a transmissivity of a substance, comprising:

• a light emitting circuit including a light emitting element and a photodetecting circuit including a photodetecting element, spaced from each other by a predetermined distance, for detecting a transmitted light value of a substance passing through a space between said light emitting element and said photodetecting circuit as a transmitted light value, a photooscillator circuit including said photodetecting element as one component element thereof which outputs a signal having characteristics selected from a cycle and a frequency corresponding to said transmitted light value, a temperature detecting circuit outputting a signal when the substance has a temperature exceeding a predetermined temperature, a discriminating circuit for discriminating the condition of the substance detected by the signal output from the photooscillator circuit and comprising a reference signal generating circuit, a counting circuit for counting clock pulses, a power circuit supplying a power to said temperature detecting circuit, a timing circuit, a count of which is started by a clock pulse of the output signal of said reference signal generating circuit, and which passes the clock pulse to said counting circuit when the output signal of said temperature detecting circuit is input and which stops the counting operation and outputs a signal for cutting off said power circuit supplying a power to said temperature detecting circuit when a predetermined number of pulses are counted by said counting circuit, the count of said counting circuit is started when a clock pulse from the count circuit is input thereto, and the output signal of the photooscillator circuit is input to a reset terminal thereof, and when a predetermined number of the clock pulses are counted up before a reset signal is input thereto from said oscillator circuit, the count thereof is stopped and a signal for actuating a warning lamp circuit is output.

A device for detecting a transmissivity of a substance, comprising a light emitting circuit including a light emitting element, a photodetecting circuit including a photodetecting element, each of which are spaced from each other by a predetermined distance so that a transmitted light value of a substance passing through a space between said photodetecting element and said light emitting element is detected as a transmitted light value, a photooscillator circuit including said photodetecting element as one component element thereof which outputs a signal having characteristic s selected from a cycle and a frequency corresponding to said transmitted light value, a detecting operation controlling circuit comprising a first timer circuit which begins to count reference signals after a signal corresponding to a startup signal of an engine is input to the reset terminal thereof, and outputs a signal for stopping the counting operation thereof when a output signal of a second timer is input thereto, and for starting the discriminating operation of a discriminating circuit, after a predetermined number of pulses are counted, and a second timer circuit which starts to count up reference signals when power is supplied thereto and outputs a signal for stopping the count thereof and for starting the count of the first timer after a predetermined number of pulses are counted and is reset when a signal corresponding to an engine stop is input to a reset terminal thereof, a discriminating circuit for discriminating the condition of the substance detected by the signal output from the photooscillator circuit comprising a reference signal generating circuit, a timing circuit, the count of which is started by a clock pulse of the output signal of said reference signal generating circuit and which passes the clock pulse to a count circuit when the output signal of said temperature detecting circuit is input thereto and stops the count and outputs a signal for cutting off a power circuit supplying power to said temperature detecting circuit when a predetermined number of pulses are counted up, a counting circuit the count of which is started when the clock pulse from the count circuit is input thereto, and the output signal of the photooscillator circuit is input to a reset terminal thereof, and when a predetermined number of the clock pulses are counted before a resetting signal is input thereto from said oscillator circuit, the count thereof is stopped and a signal for actuating a warning lamp circuit is output.