The Do-It-Yourself Race Timer

This page is dedicated to all of the leaders of Scouting organizations who contribute their time and effort so that boys and girls can have the opportunity to learn and grow while having fun.


Purpose

This page and its associated pages were created so that we, the designers of this timer, could share our design with others. It is our hope that our efforts will help you to foster good sportsmanship in children, through friendly and fair competition. While it is true that many methods exist to fairly judge simple racing events, we believe that a timer with automatic start and finish detection provides a certain level objectivity and accuracy not found in other methods.


Intended Audience

The plans presented here are intended for the typical electronics hobbyist. It is assumed that the reader is familiar with the basic priciples of electronics, has some experience with simple soldering techniques, and is able to read and interpret a schematic diagram of a moderately complex electronic circuit.


Disclaimer

Although the race timer circuit described in these documents has been tested under a variety of conditions, it is impossible to predict and test under all possible circumstances to which the circuit may be subjected. Furthermore, many performance aspects are directly linked to the physical layout of the components and the method of connection and enclosure. Therefore these plans are provided as-is, without any type of warranty whatsoever, including warranties of personal safety or fitness for any particular application. You assume all risks and liabilities incurred from the construction, use, attempted use, or inability to use the circuit described in these documents.

In other words... You built it, not us!


Copyright Notice

This hypertext document, together with the related hypertext and image documents describing the construction and use of an electronic race timing device, are the property of their Author, Kristin Hammond. The Author reserves all rights with regard to these documents, and grants to You certain permissions as described below.

The Author hereby grants You permission to make and distribute copies of these documents under the following conditions:

  1. The Author expects no compensation as a result of Your use or distribution of these documents.
  2. You may charge the Recipient a fee which does not exceed Your actual cost of providing the Recipient with a copy of these documents.
  3. This Notice grants the same privileges to the Recipient as it grants to You. You must not restrict or inhibit the Recipient's privileges that are granted by this Notice.
  4. You must include with each copy both the Disclaimer above and this Copyright Notice.
  5. To be considered an Unaltered Copy, the copy You distribute must include the entire text of this hypertext document and of all of the hypertext documents directly linked in this hypertext document, and also must include all of the images contained in the image documents directly linked in this hypertext document. If the text is materially changed, or if any part of a required image is materially changed or illegible, then the copy shall be considered an Altered Copy.
  6. If You distribute an Altered Copy, then You must include a statement indicating that it is an Altered Copy and listing the sections which have been omitted or changed.
  7. You are responsible for retaining an Unaltered Copy of these documents for at least 1 year from the date when You distribute an Altered Copy. If during that period the Recipient of an Altered Copy of these documents requests an Unaltered Copy, then You must provide an Unaltered Copy of these documents. You must not charge the Recipient for the first Unaltered Copy requested under this condition.

The Author hereby grants You permission to produce and distribute Derivative Works based on these documents under the following conditions:

  1. The Author expects no compensation as a result of Your use or distribution of the Derivative Work.
  2. You must include with every distribution of Your Derivative Work the Disclaimer above, this Copyright Notice, and a statement indicating that the Derivative Work is based on the Author's work.
  3. You are responsible for retaining an Unaltered Copy of these documents for at least 1 year from the date when You distribute a Derivative Work. If during that period the Recipient of a Derivative Work requests an Unaltered Copy, then You must provide an Unaltered Copy of these documents. You must not charge the Recipient for the first Unaltered Copy requested under this condition.
  4. Any derivative of the Derivative Work shall itself be considered to be a Derivative Work and shall be bound by these conditions, unless it can be shown to be based solely on components of the Derivative Work which are not related to the work of the Author.


Acknowlegements

The race timer circuit described here was originally designed, tested, and developed in 1997 by a group of Electrical Engineering students working on a volunteer basis in their free time. The goal was to build a stand-alone race timer for a local Cub Scout Pack to use in its annual Pinewood Derby. The timer worked so well that the design team decided to share the circuit design with other groups. The plans for a two-lane timer were first published on the World Wide Web in 1998. Since that time, the designers have received requests for three-, four-, and six-lane timer circuit designs. In 2001, the schematic diagrams and supporting documents were updated to reflect some minor design changes and to make the schematics more readable.

The following individuals and groups have been instrumental in the development and maintenance of this race timer design.


Race Timer Plans

Parts Needed

Circuit Diagrams Supplementary Material


Copyright © 2001 Kristin Hammond

Send comments and requests for technical assistance to PineTimer@aol.com

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