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. Gemini personnel 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.

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

Gemini also manufactures a series of standard and custom Reflex control modules and SCR power controllers to meet your OEM or USER needs. Gemini Controls performs contract electronic assembly work for many different companies from simple boards to completely packaged products. Both small and large quantities are welcome. Gemini can build your product using parts you supply or we can source the parts for you. Gemini 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

Al Wilkerson was the guru of the electronics world and was well known for his design expertise. Life long entrepreneur, Al started Gemini at it’s present location in 1979. Al created a unique family work environment, blending the skills and talents of a wide variety of workers. He loved the challenge of designing new products to meet customer needs. Al passed away December 13, 2009 and is greatly missed.

Al Wilkerson

Sherry Jones

Sherry Jones

Sherry Jones has been with Gemini since December 1, 1981. Sherry and her husband Al Wilkerson ran the business together until Al passed away in Dec. of 2009. Sherry has taken over as president of Gemini with Al’s wishes and continues the manufacturing of motor speed controls.

Sherry loves to coordinate social gatherings for the company staff and friends, cooking, and gardening & landscaping. We are a family here at Gemini.

Gary Dobberfuhl
Materials Manager / Accounting / Repairs / Shipping Manager

I started with the Gemini Controls LLC Family as their Materials Manager in October 1993. As my time progressed at Gemini I have added the titles of Accounting and Repairs Manager. At Gemini I take care of the inventory of parts, receiving them in and pulling them for jobs. I also take care of the accounting duties such as paying invoices, payroll, and receiving payments. In addition I handle all the repair paperwork on products sent back to us for repair and sales of replacement treadmill drives. Also I am Gemini's shipping manager.

In my free time I enjoy walking, bowling and golf.

Sherry Jones


Al Wilkerson

Jim Mueller

After a favorable interview I was adopted into the Gemini family in May 1988. Tested production run boards and repaired them too. Created test fixtures, learned CAD programs for board layout, designed drive packaging, and became the machinist of aluminum bar stock to make production parts and heat sinks.

Other areas of expertise include food preparation for Gemini company parties and musky fishing

James Bartelt
Chief Technician / Shop Foreman

I joined the Gemini Controls LLC Family as an Electronic Technician in September 1992 after graduating with Highest Honors from ITT Technical Institute with an Associates Degree in Electronic Engineering Technology. I have since advanced up to Chief Technician and Shop Foreman. I handle 95% of production testing and repairs from the field. I also supervise our highly talented shop force keeping production moving smoothly. I take care of all interactions between Gemini Controls and UL & CSA for our customers. In addition I manage Gemini’s eBay store and create various marketing brochures.

In my free time I enjoy Camping, Fishing, Photography, and Model Railroading, both HO Scale and a G Scale Garden Railroad.

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

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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