Electric home appliances
First Claim
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1. An electric home appliance incorporating a control system comprising sensor means having an impedance value variable with variations in temperature, humidity or other state;
- a control circuit connected to the sensor means and including oscillator means, counter means for counting the number of oscillating output pulses from the oscillator means, and means for determining gating time for the counter means;
characterized in that the oscillator means has an oscillation frequency directly defined by the impedance value of the sensor means, the oscillator means having an oscillation time constant determined by a plurality of impedance elements independent of the electric impedance of the sensor means, and change-over switch means for selectively connecting said independent impedance elements to the oscillator means.
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Abstract
An electric home appliance which is automatically controllable with use of a sensor such as temperature sensor or humidity sensor. Variations in terms of analogue quantities given by the sensor are converted to variations in the number of pulses by an oscillator connected to the sensor and comprising an astable multivibrator or the like. The number of pulses is counted by a counter, the gating time of which is determined for example by divided frequency of a commercial power supply. The control system is inexpensive to make and has high reliability.
24 Citations
9 Claims
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1. An electric home appliance incorporating a control system comprising sensor means having an impedance value variable with variations in temperature, humidity or other state;
- a control circuit connected to the sensor means and including oscillator means, counter means for counting the number of oscillating output pulses from the oscillator means, and means for determining gating time for the counter means;
characterized in that the oscillator means has an oscillation frequency directly defined by the impedance value of the sensor means, the oscillator means having an oscillation time constant determined by a plurality of impedance elements independent of the electric impedance of the sensor means, and change-over switch means for selectively connecting said independent impedance elements to the oscillator means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a control circuit connected to the sensor means and including oscillator means, counter means for counting the number of oscillating output pulses from the oscillator means, and means for determining gating time for the counter means;
Specification