Solar Tracker Circuit Kits from MTM Scientific, Inc

Solar Tracking Kits, Motors, Sensors, Circuit Booklet and Photos of Customer Projects

The new and improved solar tracker kit...

Photo of Solar Tracker Circuit Kit after assembly (Catalog #ST2)

The SOLAR TRACKER 2 CIRCUIT KIT (Catalog #ST2) from MTM Scientific contains all the electrical parts you need to build a circuit which will automatically find and follow the sun across the sky. This single axis tracker circuit finds the sun at dawn, follows the sun during the day, and resets for the next day. This kit is perfect for driving a single axis solar tracker with a 12 VDC gear motor or linear actuator that you provide. The kit includes 2 photocells, an IC comparator, resistors, diodes, 2 limit switches, 2 relays, terminal connectors and a 20 page booklet.The printed circuit board is also included with the kit, which makes it easy to assemble and test the circuit quickly. The tracker circuit is powered by the same 12 VDC that drives your motor. Single axis solar tracking is great for projects such as solar optical concentrators, solar ovens, fresnel lenses, and solar electric photovoltaic panels. The detailed instructions include the circuit diagram, an explanation of how the circuit works, a description of how single axis sun tracking works and advice for selecting a DC gearhead motor. This kit is perfect for the person that wants a quick start on building a single axis solar tracker. NEW FEATURES of ST2: This updated solar tracker design includes many new and useful features suggested by our customers during the last 15 years. This circuit has automatic reset to the East at sunset to capture first light the next morning (Which can also be disabled: if desired, for 2 axis projects). Another useful feature is the simplified wiring connections, which are all made using screw type wire terminals. The circuit board  (2.5 x 2.75 inches) has been designed to fit inside a standard outdoor junction box. In addition, the ST2 allows using a motor power supply voltage other than 12 VDC, for example a 24 VDC linear actuator. Please note that this is a kit which requires assembly and soldering. You  must provide a 12 VDC power supply, wire, mechanical parts and a DC motor (or Linear Actuator) for your single axis sun tracking project to be complete.

Solar Tracker Circuit Specifications: 3 Amp Max Motor Current, 12 VDC Supply

Need higher current?  See the Heavy Duty Kit (ST2HD) below...

Please note: This circuit kit is for controlling a 12 VDC electric motor or linear actuator that you provide. To track the sun you will also need to build the mechanical drive for having your motor move your project. The instruction booklet gives some examples... Also see the link to customer project examples below. Need Dual Axis? A dual axis tracker can be built by using 2 kits.

12VDC Gear Head Motor

Photo of DC Gearheard Motor (Catalog #ST2M is the #ST2 kit with this motor.)

Our DELUXE SOLAR TRACKER KIT #ST2M includes a small 12 VDC Gear Head Motor with the #ST2 circuit kit (above).  This is a great way to get a jump start on your project.  We are offering this motor in response to numerous requests for a basic low RPM DC motor. The speed at 12 VDC is 7 RPM.  The motor shaft size is 5mm (0.197 inches) with a set screw flat, and the overall dimensions are approximately 1.25 inches diameter by 2.5 inches long. This small electric motor is surprisingly powerful.  It cannot be stopped by hand. We are offering this motor combined with a Solar Tracker Circuit Kit (above) to create a Deluxe Kit for $71.50, USA shipping included. International Customers: Please order #ST2M-INT which includes $10.00 additional for worldwide shipping by Postal Mail, as the weight of the motor increases the cost of shipping substantially. 

... $81.50, International Shipping Included.  We ship this item by Postal Mail worldwide. Travel time is usually 2-3 weeks. Unfortunately tracking information is not available.  We have sent this item all over the world without problem. Customers from Italy: Please email for special conditions.

MOTOR ONLY (Catalog #MOTOR)... $20.00,  USA Shipping Included Some customers have asked to purchase the Motor (shown above) separately.This is the same motor we include with the kit above. Every motor includes a small snubbing resistor to promote long relay life. This low RPM DC motor is useful for hobbyists that are building a project according to the plans in our E-Booklet. The quantity can be changed at checkout to order more than one. We ship this item by 1st Class Mail in the USA. International Customers: Please use the link for International Orders which provides an additional $10.00 for the postage, as this motor is heavy to ship by mail. 

Heavy Duty Solar Tracker Kit (ST2HD)

Heavy Duty Solar Tracker Kit

Photo of Assembled Heavy Duty Solar Tracker Circuit Kit (Catalog #ST2HD)

The HEAVY DUTY SOLAR TRACKER CIRCUIT KIT (#ST2HD) has an 8 Amp current rating. This kit was created in response to customer requests for a higher current version of our standard kit. Note that the 2 larger relays and IC are socketed for easy replacement. The 2 limit switches we include also have a higher current rating. The circuit board for this kit is slightly larger (2.5 x 3.8 inches) and will require a larger enclosure. Otherwise, the function of this kit is exactly identical to our standard #ST2. This Heavy Duty kit also includes the 20 page Solar Tracker Booklet mentioned above. Please note that this is a kit which requires assembly and soldering.


We also offer a special version of our Solar Tracker Kit which features a PICAXE-08M microcontroller. This special kit is software controlled with a Basic computer program. Advanced hobbyists have modified the program for special applications. Please read more about this advanced kit here:

Computer Chip Controlled Solar Tracker: Special Offer


How to build a solar tracker

If you are certain that a dual axis solar tracker is needed for your project, then you should read this book! Now available, our book "Build a Solar Tracker: How to build a dual axis sun tracking system"

STMAX: Dual Axis Solar Tracker New Release Announcement


The SOLAR TRACKER E-BOOLET (CAT #STBK) contains 49 pages of detailed information about building Solar Trackers, with a special emphasis on using the basic MTM circuits. This E-Booklet contains the circuit diagrams for ALL the MTM Solar Tracker products, including the new PICAXE version. This booklet contains 47 illustrations and photos, and also contains design tips for weight, balance, bearings, sensor protection and motor snubber resistors. Also included are details for building a manual East-West switch for testing your tracker. Additionally, the BASIC source code listing for our PICAXE solar tracker is included. This Solar Tracker E-Booklet is perfect for a fast start on designing and building your Solar Tracker Project. Note: This is an electronic booklet in PDF format.  Please write to us by email if you would like to purchase. (

Solar Tracker E-Booklet (Catalog #STBK) $10.00

Photocell Sensors for MTM Circuits

Photo Sensors for the MTM Kits and Circuits (Catalog #PHTCLL)

Here are the same PHOTOCELL SENSORS (#PHTCLL) we use in all the basic MTM Solar Tracker Kits. (All our kits include these sensors.) Our sensors are selected and matched specifically for Solar Tracker applications. They will work perfectly as spares or replacements in all the MTM kits. You will receive 2 pairs (4 sensors total) as shown in the photo. These sensors are also useful if you are building a homebrew tracker based on any of the circuit diagrams in our Solar Tracker E-Booklet. Please note that our $20 price includes FREE shipping by Postal Mail to the USA only. International shipping is not available.

Note: Please inquire by email to purchase any of our products. We will send a Paypal 'Request for Payment'

Video of a Demonstration Solar Tracking Project

Here is an example of a small single axis solar tracker with a short demonstration video. In this example a solar panel has been mounted directly to the shaft of a large DC gearhead motor. The MTM solar tracker kit is used to control the motion. Please note that the MTM kits (above) DO NOT include this solar panel or the large motor shown here!  See more examples of solar tracker projects on our customer page (link below).

Solar tracking for a Solar Cell Panel Demonstration Video

Here is a link to more examples of solar trackers built by our customers:

Solar Tracker Project Examples from MTM Scientific Customers

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