Temperature detector
First Claim
1. A detecting device comprising:
- a first circuit portion including an electrical detecting element whose resistance varies according to changes in a parameter to be detected and a variable voltage dividing circuit connected in series with said detecting element, said variable voltage dividing circuit having at least two resistance elements connected in series with each other and at least one switching means connected in parallel with those resistance elements of said at least two resistance elements which are other than at least one thereof in order to selectively vary the resistance of the variable voltage dividing circuit,a direct-current power supply for applying direct-current power to said first circuit portion,a switching control means for maintaining said switching means in conduction for a predetermined period of time with a predetermined cycle, anda comparison means for comparing a first divided voltage at a point of connection between said detecting element and said variable voltage dividing circuit with a standard voltage, the results of such comparison indicating detection of the change in the parameter.
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Accused Products
Abstract
An electrostatic copying apparatus having a semiautomatic document supplying and discharging device and a sorter in addition to its main body. The main body of the apparatus includes a rotatable photosensitive member, a device for forming a latent electrostatic image on the photosensitive member, a developer, a transfer device, a device for conveying a copying paper, a cleaner and a heat fixing device. Various improvements have been made in the manner of controlling cleaning, the manner of controlling the delivery of a copying paper, the manner of controlling troubleshooting and display, the manner of controlling interrupting copying, the manner of controlling heating, the manner of distribution electric power, etc. The heating is controlled by a parallel network of linear circuits including a temperature detector and a multi-element voltage dividing circuit, the elements of which can be switched into and out of operation to alter the sensed temperature to which the network responds.
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Citations
8 Claims
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1. A detecting device comprising:
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a first circuit portion including an electrical detecting element whose resistance varies according to changes in a parameter to be detected and a variable voltage dividing circuit connected in series with said detecting element, said variable voltage dividing circuit having at least two resistance elements connected in series with each other and at least one switching means connected in parallel with those resistance elements of said at least two resistance elements which are other than at least one thereof in order to selectively vary the resistance of the variable voltage dividing circuit, a direct-current power supply for applying direct-current power to said first circuit portion, a switching control means for maintaining said switching means in conduction for a predetermined period of time with a predetermined cycle, and a comparison means for comparing a first divided voltage at a point of connection between said detecting element and said variable voltage dividing circuit with a standard voltage, the results of such comparison indicating detection of the change in the parameter. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A detecting device comprising:
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a first circuit portion including an electrical detecting element whose resistance varies according to changes in a parameter to be detected and a variable voltage dividing circuit connected with said detecting element, said variable voltage dividing circuit having at least two resistance elements and at least one switching means for selectively varying the resistance of the variable voltage dividing circuit, a power input means adapted for connection to a direct-current power supply for applying direct current power to said first circuit portion, a switching control means for maintaining said switching means in conduction for a predetermined period of time with a predetermined cycle, and a comparison means for comparing a first divided voltage at a point of connection of said detecting element and said variable voltage dividing circuit with a standard voltage, the results of such comparison indicating detection of the change in the parameter. - View Dependent Claims (8)
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Specification