NOVELTY - Control method for use in a thermoelectric generator control system, comprises monitoring a voltage output of the thermoelectric generator; determining a voltage change on the voltage output; calculating an adjustment for DC-DC (sic) converter in response to the voltage change on the voltage output such that an output voltage from the DC-DC converter remains at a predetermined voltage level; and applying the adjustment to the DC-DC converter.    USE - For use in a thermoelectric generator control system, e.g. in internal combustion engine exhausts.    ADVANTAGE - The method may be incorporated in any vehicles or work machines where it would be desirable to recover waste heat energy and contribute to the increased overall efficiency of a waste heat generating system. By recovering a portion of the waste heat energy, vehicles or work machines may become more efficient and use less fuel. The method also provides a stable and constant power supply generated from waste heat energy. Because energy levels generated from waste heat can vary significantly, the method can automatically and effectively convert a variable output voltage from a thermoelectric generator to a constant voltage at a desired level.    DETAILED DESCRIPTION - Control method for use in a thermoelectric generator control system having a thermoelectric generator, DC-DC converter, and controller, comprises:    (a) monitoring a voltage output of the thermoelectric generator;    (b) determining a voltage change on the voltage output;    (c) calculating an adjustment for the DC-DC converter in response to the voltage change on the voltage output such that an output voltage from the DC-DC converter remains at a predetermined voltage level; and    (d) applying the adjustment to the DC-DC converter.    An INDEPENDENT CLAIM is also included for a thermoelectric generator system for use on a work machine having an engine, comprising:    (a) thermoelectric generator selectively accepting an exhaust stream from the engine to generate a voltage on a generator voltage output;    (b) DC-DC converter having a voltage input coupled with the generator voltage output of the thermoelectric generator to convert the voltage to a predetermined level on a converter voltage output; and    (c) controller coupled to both the DC-DC converter and the thermoelectric generator and configured to maintain the predetermined level on the converter voltage output.    DESCRIPTION OF DRAWING(S) - The figure illustrates a block diagram of a power sub-system.