Patent ID: 6118370
Filing Date: 2000-09-12
Classification: G01K

Abstract:
A circuit for a two-stage temperature gauge, said gauge giving a first indication when the temperature is at or below a threshold value and giving a second indication when the temperature exceeds the threshold value, said circuit comprising:input means for receiving a signal representative of temperature for causing the gauge to give one of the first and second indications, said input means including a terminal;branch circuit means connected to said input means for controlling the gauge so that the gauge gives the first and second indications, said branch circuit means including a diode having an anode connected to said branch circuit means and a cathode connected to said terminal, said branch circuit including a resistor having a first end coupled to a controllable source of positive voltage, a first coil with a first end connected to a second end of said resistor and with a second end connected to said anode of said diode, a second coil with a first end connected to said anode of said diode and with a second end coupled to ground, and a third coil with a first end connected to said second end of said second coil and with a second end connected to ground; andan indicating lamp connected to said input means, said lamp illuminating when the temperature exceeds the threshold value.