Circuit energization indicator with thermal timing means to maintain the indication for a predetermined time after de-energization

A thermal timer, comprising storage means for storing thermal energy in a thermally insulative environment having a predetermined thermal energy leakage rate, supply means for supplying thermal energy to said storage means to change the temperature of the latter from one to another temperature, and thermally responsive output means for producing a distinguishable output in response to the temperature thereof, said output means being positioned relative to said supply means to produce such distinguishable output promptly upon the initiation of the latter to supply such thermal energy, and said output means also being positioned relative to said storage means to produce such distinguishable output in response to and generally indicative of the temperature of said storage means after said supply means ceases to supply such thermal energy, the duration of continued production of such distinguishable output after termination of a supply of thermal energy by said supply means to said storage means being proportional to such thermal leakage rate.