Linear electric motor controller and system for providing linear speed control

A linear power module protecting system, comprising:

• an electric motor;
• an application specific integrated circuit operatively coupled to the motor;
• a power MOSFET utilized as a variable resistor with switch function, the MOSFET's parasitic body diode providing an opposite current path in response to reversed polarity applied to the MOSFET, thereby protecting the power MOSFET, the MOSFET having a breakdown voltage;
• a zener diode for clamping the voltage across the MOSFET, the zener diode having a breakdown voltage;
• a diode coupled in series to said zener diode for providing electric isolation between gate and drain of said MOSFET;
• a resistor coupled to the power transistor for limiting the current through the zener diode and the first diode;
• and
• a combined input diodes set for restricting the direction of current flow to the integrated circuit and clamping the reversed voltage across an ASIC power supply, the combined input diodes having a breakdown voltage.

A system for reducing thermal impedance in an electronic power switch of an electric motor linear speed control system, comprising:

• an electric motor;
• at least two temperature FETs coupled in parallel for controlling the power of the motor;
• an integrated circuit for controlling the at least two parallel temperature FETs;
• and
• each temperature FET having its drive voltage offset by the integrated circuit to track temperature of another temperature FET.

An apparatus for protecting against a locked rotor condition in an HVAC system, comprising:

• a temperature FET circuit including a FET, and a pair of temperature sensitive diodes disposed over the junction of the FET, thereby keeping temperature of the diodes consistent with the FET;
• a direct current electric motor;
• and
• an integrated circuit, including a temperature comparator block, a current source block, a timer block with an external time-setting capacitor, and a FET drive block.