Heat level indication method and apparatus

Abstract

A method for indicating the thermal state of cooking appliances with an optical and/or acoustic signalling device, comprising the steps of: counting forward from a starting number in response to the heating means of the cooking appliance being switched on; and, counting backwards after the heating means of the cooking appliance has been switched off, the signalling device being switched on when the count exceeds a first number and being switched off when the count falls below a second number. An apparatus for indicating the thermal state of cooking appliance with an optical and/or acoustic signalling device, comprising: an electronic bidirectional counter; clock generating logic for controlling clock pulses to the counter; a detector connected to the logic for determining the switching on and off of the heating means of the cooking appliance, the counter being clocked upwardly after the switching on, and being clocked downwardly after the switching off; and, at least one count recognition circuit connected to the counter, which on reaching predetermined numbers switches the signalling device on and off. In both the method and apparatus the rate of forward and backward counting can be made proportional to the actual heating and cooling characteristics of the cooking appliances.