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Dierking Transit Detector
Basic Kepler transit dectector model/simulation  

Here are parts for the Kepler transit dectector model/simulation made by Bryan and Richard Dierking.

Various size planets (styrofoam balls) can swing in orbit on a string, pendulum-style. This set-up shows a light socket on a stand used for a halogen light. Any stand could be used that had a wide/heavy base. Styrofoam balls were spray painted—paint has to be applied in several light coats to prevent the solvent from melting the styrofoam. These balls are light enough to reduce the chance of breaking the light bulb if one of the students were to inadvertently bump the lamp.

 

detector model parts
Bryan Dierking at the workbench with tools and parts he used to build a detector. It took him approximately one hour to construct the detector.  To connect the wires, his dad, Richard, asked him to use splice connectors and a crimping tool. Alternatively, the wires could be soldered together.
Bryan at work table
Photo electric cell inserted through two pieces of cardboard. Bryan used a paperclip to punch the holes in the cardboard. He inserted the cardboard with the cell into the end of the tube and fastened with electrical tape. Also, he secured the wires to the outside of the tube so the connections would not get pulled out from handling.
photocell
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The completed detector. The circuit is very simple. For detecting, the analog multimeter is just set for the 10 VDC scale.
completed detector
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Kepler transit dectector with mirror optical system  
Parts for the Dierking transit detector with mirror optical system.
Parts for detector with reflector light intensifier
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Oatmeal lid mirror mirror mount. We cut the bottom of the container for the opening, and glued the mirror to the inside of the lid with epoxy. This way, the mirror can be easily removed for cleaning.
Oatmeal lid mirror holder
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Photocell mounted on a wooden stir stick. The photo cell is enclosed in a small cup created using model rocket body tube and balsa wood. The cup was glued on a stir stick and inserted through the end of the tube.
photocell mounted on a popsicle stick
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We placed the stick 3/16" from the end and centered, near the focal point of the mirror.
Completed detector with optical system. We used a empty container of Quaker Oaks for the tube, painted inside and out with flat black paint and a straw glued along the axis for sighting.
completed detector with optical system
Close-up of optical system. The leads from the cell were soldered and we just attached the multimeter using test leads with alligator clips.
Close-up of optical system
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Parts List for Inexpensive Model/Demo Photometer with Reflector Light-Gatherer
Description Quan Supplier Part # Price
Digital Multimeter with 20 VDC Scale Each Home Depot
Assorted Photo Electric Cells Pk of 5 Radio Shack 276-1657 $2.99
9 Volt Battery Snap Connectors (Heavy Duty) Pk of 5 Radio Shack 270-324 $2.69
9 Volt Battery - - - -
Approximately 6' of 22 Gauge Wire (Speaker Wire) - - - -
Magnification Mirror (Swissco 10X Mag., 3.5" Diameter, #8110) Each Long's Drug Store $4.99
Quaker Oats Container - Tube and Lid (Approx. 4" Dia.) - - - -
Wooden Stir Stick - - - -
Top from a Tube of Toothpaste - - - -
Heavy Duty Straw - - - -
Flat Black Spray Paint - - - -
5 Minute Epoxy - - - -