Patent ID: 6893153

Claim:
A temperature-indicating power adapter comprising: a case; a conversion module coupled to the case that receives a first voltage and produces a second voltage, the case dissipating at least some of the heat generated by the conversion module; a temperature-indicating device also coupled to the case for indicating the temperature of the case, wherein the temperature of the case increases due to the heat produced from a conversion of the first voltage into the second voltage; wherein the temperature-indicating device comprises: a temperature sensitive resistor that changes resistivity in response to a change in the temperature of the case; a comparator coupled to the temperature sensitive resistor and configured to generate an output based upon the resistivity of the temperature sensitive resistor; a diode; a transistor coupled to the diode and the comparator, the transistor configured to switch a state of the diode based upon the output of the comparator; a second diode; and a second transistor coupled to the second diode and the comparator, the second transistor configured to switch a state of the second diode based upon the output of the comparator, wherein the second diode has a state that is opposite to the state of the other diode.