Power-Tronics, Inc. was founded in January 1989 as an electronic repair center for electrical generator voltage regulators and various types of electronic and relay controls.

After a patent was issued to founder Paul L. Herbert for an electronic circuit that would allow exact matching of an exciter input to generator voltage reaction time, total emphasis was turned to experimentation and manufacturing of a universal voltage regulating system for electrical generators.

The new voltage regulating system was designed to require very few selections of regulators and accessories to replace and repair many different types, models, and brands of voltage regulators used in the industry. The reduced stocking requirements and ease of setup effectively results in simplification of installation and reduction of expense in generator voltage regulating system repair and replacement.

In 1990, manufacturing began on a VR500 series universal voltage regulator that would replace most manufacturers’ models and would do so without the necessity of special transformers or the addition of supplemental field resistors. As production and sales increased, customers requested replacements for older rotary exciters and Power-Tronics, Inc. began the manufacture of the SE series of static exciter modules and full static exciters.

Originally founded in Corpus Christi, Texas, Power-Tronics, Inc. moved its corporate office to Kerrville, Texas in 1995. After relocating to the Texas Hill Country, Power-Tronics, Inc. expanded its production capacity and focused on refinement of its product catalog.

In July of 1997 Power-Tronics, Inc. moved into its new custom-built manufacturing facility, which allowed a major expansion of manufacturing and operations. Expansion fostered a new line of products such as static exciters for retro-fits on larger hydro and turbine generators and custom design of power-controls for the electrical generator and motor industry.

In 2011, Power-Tronics began production of the XR500D series universal voltage regulator, a product that greatly simplified the installation and setup of alternate brand/system generator conversion.  The D-series voltage regulator contains new circuitry that automatically adjusts itself to the generator, eliminating the need for manual matching of the regulator to the generator, simplifying installation requirements even further than previous regulator designs.

Power-Tronics continues to build its products in analog format instead of digital due to the proven long life expectancy and relative durability of analog systems. Our analog systems have the same or better voltage regulation as digital systems and can be used with external controls such as genset controllers, VAR controllers, or any other system that has an analog or digital output signal.  Thanks to our unique voltage regulation system, initial setup requires no computer programming, PID tuning, or other complicated and frustrating setup procedures.

Our technicians offer onsite troubleshooting and field service, custom design for retro-fits, engineering assistance, electrical troubleshooting, and from time to time we offer field service schools designed for generator field service technicians.

For over 25 years Power-Tronics, Inc. has been serving the international electrical generator service and repair industry and has customers located worldwide.

Power-Tronics, Inc. has been a family-owned business since its founding and is currently in transition from one generation to the next.




VR500 Series


Patent Awarded


Relocation to Kerrville, TX


Custom Facility / Expansion


Product Line Expansion / Customization


XR500D Series


Onsite Troubleshooting Offered


Generational Transition / Product Line Expansion


Operations Manager Eric Herbert has many years experience with hands-on troubleshooting of voltage regulation problems and voltage regulating system retrofits and upgrades.  He has attended several trade schools to improve his knowledge of the power-generation field, including several courses offered by EGSA.  Additionally, Eric has held certification through EGSA’s Certified Generator Technician program since 2009.  As the son of the company’s founder, Eric is dedicated to preserving the same high-quality, reliable products that Power-Tronics has developed a reputation for.  Power-Tronics, Inc. is a proud member of the Electrical Generating Systems Association (EGSA), the San Antonio Manufacturers Association (SAMA) and is pleased to manufacture its products domestically in Kerrville, Texas USA.

SAMA LogoEGSA Certified LogoEGSA LogoManufactured in Texas