A voltage regulator is configured to receive an input voltage from a power supply, measure a temperature associated with a heat transfer medium, produce an output voltage to drive a thermo-electric cooler, and vary the output voltage in accordance with changes in the measured temperature. Varying the output voltage results in: 1) extracting of heat from the heat transfer medium when the measured temperature is above a threshold value, or 2) supplying of heat to the heat transfer medium when the measured temperature is below a threshold value. The voltage regulator can cap upper and lower bounds of the output voltage to prevent the thermo-electric cooler from reaching its saturation point. The voltage regulator can be configured to produce an output voltage having reduced voltage ripple.