W61 N14280 Taunton Ave. Cedarburg, WI 53012

Gemini Controls LLC, is a Woman Owned Small Business located in Cedarburg Wisconsin (USA), which was started in 1968. Here at Gemini, we have designed and manufactured electronic products for small, medium and large companies, including Rockwell, Eaton, Reflex, Sumitomo, Buehler, Tab Products, American Rotary, E.J. Cady, Spirit Fitness, Jog-A Dog, and many more. Design expertise is focused on power conversion applications such as DC adjustable speed drives, power supplies, and SCR power controllers,

Gemini pulse width modulated (PWM) DC drives are designed to operate with brush-type Permanent Magnet DC motors. The evolution of Gemini's PWM drives has led to numerous advantages over SCR based and other PWM drives, including smooth operation, audibly quiet, and less line current consumption at low speeds.

Gemini SCR DC drives are designed to operate brush-type Permanent Magnet DC motors featuring smooth operation due to high speed switching and exclusive motor inductance compensation which provides the fastest response to load and speed changes.

In the past, we have supplied controls to high volume treadmill companies. We still manufacture controls for various treadmill companies, sell replacement controls to repair shops, and repair treadmill controllers. Some of the companies we have supplied are Amadas, Bodyguard, DP, Hebb Trimline, Kurt, SST Spectrum, Spirit, Trotter/Cybex, and United Ventures Fitness. Our control can be substituted for other manufacturers as well.

Gemini manufactures a series of standard and custom Reflex control modules and SCR power controllers to meet your OEM or USER needs. Our Gemini staff performs contract electronic assembly work for many different companies, from simple boards to completely packaged products. Both small and large quantities are welcome. We can build your product using parts you supply, or we can source the parts for you. Our staff can also design circuit boards for you. Proper clearances to meet UL and CSA requirements are part of the normal layout.

Additionally, Gemini will manufacture the product to your requirements.


Al Wilkerson+
Founder and Past President

Being an electronics guru and lifelong entrepreneur with a passion for innovation, Al Wilkerson started Gemini at its present location in 1979.
By using his ability to blend the skills and talents of a variety of workers, he created a unique family working environment dedicated to
meeting customer needs. Al passed away December 13, 2009,
and he is greatly missed.

Al Wilkerson

Sherry Jones

Sherry Jones

Sherry Jones joined the Gemini team December 1, 1981 after meeting Al Wilkerson... Sherry and her husband Al ran the business together until Al passed away in December of 2009. Sherry continues to do what she loves while simultaneously fulfilling Al's wishes of manufacturing motor speed controls and providing excellent customer service.

Sherry loves coordinating social gatherings for the company staff and friends, cooking, gardening, landscaping, and doing other outdoor activities.

"We are family here at Gemini"

Gary Dobberfuhl
Materials Manager / Accounting / Repairs / Shipping Manager

Gary Dobberfuhl started working at Gemini in October of 1993 as the Materials Manager. As time has progressed, Gary has taken on the titles of Repairs Manager, Accounting Manager, and Shipping Manager. His duties include handling paperwork for products in need of repair, sales of replacement treadmill drives, paying invoices, receiving payments, taking care of the payroll, and overseeing the inventory by receiving the parts and pulling them for jobs.

In his free time, Gary enjoys walking, bowling, and playing golf.

Sherry Jones

Al Wilkerson

James Bartelt
Chief Technician / Shop Foreman

James Bartelt joined Gemini in September of 1992 after graduating from ITT Technical Institute with the Highest Honors and earning an associate's degree in electronic engineering technology. Starting as an Electronic Technician, he has since moved up to the positions of Chief Technician and Shop Foreman. His duties include handling the majority of production tests and field repairs, taking care of interactions between Gemini, UL, and CSA, managing Gemini's eBay store, and creating various marketing brochures. James also keeps production moving smoothly by supervising the company's talented engineering staff.

In his free time, James enjoys camping, fishing, photography, and model railroading.


Jim Mueller+

Jim Mueller joined the Gemini family in May of 1988. In his position, he tested and repaired production run boards, created test fixtures, learned CAD programs for board layout, and designed drive packaging. He also became the machinist of aluminum bar stock in order to make produciton parts and heat sinks.

Jim enjoyed preparing food for company parties and fishing for musky.

"The Gemini family lost Jim as a result of illness, and he is sorely missed by all of us here. He was and still is like a brother to us, and I know that his spirit is part of our work every day. Thank you, Jim, for your years of dedicated energy, friendship, and devotion to Gemini."

-Sherry and the Gemini Family


Al Wilkerson


Four legged work friends had the tough job of keeping us tension free and on our toes. They fulfilled their job admirably as the Gemini mascots.


Sherry Jones
Currently, Willy, a Shiatsu / Poodle mix, is the dog with the great responsibilities, visiting each of us every morning for a little pack bonding, watching out for us with one eye open whenever possible, and greeting visitors with a wagging tail. Life is tough being THE Gemini mascot! Oh boy is it tough! Willy even has his own email at Gemini, willy@geminicontrols.com
Sherry Jones Sadie (Tan) and Bow (brindle) were being fostered by Sherry and the gang at Gemini. They were being treated for heartworm and needed to complete the treatment before being set up for adoption. Needless to say they became permanent residence of our Gemini family in the Spring of 2016.

Sherry Jones

Casey+ was the original Gemini dog, a multi-heritage combination of intelligence and friendliness with a weakness for snowballs. He could sing with the best of them when the Beach Boys' Good Vibrations was playing on the radio.

Sherry Jones Cheddar+ was the next in the series, a personable Australian Shepherd with an uncontrollable weakness for doughnuts mixed with an endless supply of white fur. A trip to the stockroom building without Cheddar to escort you just wasn't worth making. She accompanied Casey on duets but may have been slightly off key.
Sherry Jones
Kes+ was next in succession, a used an abused Bluetick coon hound that went from scared and lost to all time champion couch potato and elbow nuzzler. She was always around to help get rid of those tasty bones and leftover lunch tidbits. Her distinctive vocalizations were unmistakable.


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