Temperature control circuit of heating wire and temperature control method thereof

Abstract

The invention discloses a temperature control circuit of a heating wire and a temperature control method thereof, wherein a positive square wave signal is output by a first positive square wave signal generation circuit, a charged or discharged reverse square wave signal is output by a reverse square wave signal, and a variable positive square wave signal is output by a second positive square wave signal generation circuit; the three square wave signal generation circuits are respectively connected with an AND gate, and a triggering circuit triggers a switch when three square wave signals are simultaneously input to be high logic so that the heating wire is heated; and when the temperature is increased, the positive square wave signal output by the second positive square wave signal changes, and the triggering circuit does not trigger the switch when the three square wave signals are non-simultaneously input to be high logic so that the heating wire stops heating, and the heating wire keeps a certain working temperature.

Description

technical field [0001] The invention relates to a temperature control circuit, in particular to a temperature control circuit of a heating wire and a temperature control method thereof, which are suitable for use in heating devices such as electric furnaces and heating blankets. Background technique [0002] Heating devices such as heating pads have been widely used in the market at present, and allowing the heating wire to be automatically interrupted after heating to the temperature set by the user can keep the heating device within the predetermined heating range, so as to Provide functions such as hot compress and ensure safe use. [0003] In order to effectively achieve the effect of temperature control, U.S. Patent No. 5,861,610 uses a positive temperature coefficient (Positive Temperature Coefficient, PTC) element as a detection line to sense changes in temperature, and at the same time is equipped with a heating line for temperature control heating . Among them, wh...

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Problems solved by technology

[0005] The overall circuit structure of the above-mentioned U.S. Patent No. 7,180,037 is quite complicated. In particular, the temperature control effect must be achieved through the simultaneous detection and calculation of the time difference determiner circuit and the controller. In this way, the cost of manufacturing will be increased. room for improvement

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