Thermally controlled circuit using planar resistive elements

A circuit board, comprising:

• a substrate;
• a heater comprising one or more planar resistive elements composed of a substantially resistive material, said one or more planar resistive elements being carried by said substrate;
• a power source selectively coupled to said heater;
• and
• thermal control circuitry configured for selectively coupling said power source to said heater;
• wherein said thermal control circuitry comprises:
• a thermostat having a temperature set point, said thermostat configured to sense a temperature level and output a signal when said temperature level crosses said temperature set point;
• a switch operatively coupled to said power source and said heater to selectively couple said power source to said heater and decouple said power source from said heater;
• and
• a logic unit programmed to operate said switch based on said thermostat output signal.

A circuit board having a temperature-sensitive functional electronic component thereon, comprising:

• a substrate;
• a heater comprising one or more planar resistive elements composed of a substantially resistive material, said one or more planar resistive elements being carried by said substrate;
• a power source selectively coupled to said heater;
• and
• thermal control circuitry configured for selectively coupling said power source to said heater to maintain said functional electronic component within predefined temperature limits;
• said thermal control circuitry being configured for selectively coupling said power source to said functional electronic component.

A circuit board, comprising:

• a substrate;
• and
• a heater comprising one or more resistive elements composed of a substantially resistive material, said one or more resistive elements being embedded within said substrate;
• at least one thermostat and logic circuit configured to generate at least four set points, including two high and two low set points, such that at least first and second temperature ranges are defined, said logic circuit being configured to actuate said first heating power level responsively to a detected temperature being in said first temperature range and to actuate said second heating power level responsively to said detected temperature being in said second temperature range.

A circuit board, comprising:

• a substrate;
• and
• a heater comprising one or more resistive elements composed of a substantially resistive material, said one or more resistive elements being embedded within said substrate;
• the size and number of said one or more resistive elements being determined based on one or more predetermined thermal criteria.

A circuit board having a temperature sensitive component thereon, comprising:

• a substrate;
• and
• a heater carried by said substrate, said heater comprising one or more planar resistive elements composed of a substantially resistive material;
• a temperature controller configured to activate and deactivate said heater and said component responsively to a sensed temperature of said component.

A circuit board, comprising:

• a substrate;
• and
• a heater carried by said substrate, said heater comprising one or more planar resistive elements composed of a substantially resistive material;
• the size and number of said one or more resistive elements being determined based on one or more predetermined thermal criteria.