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[DPRG] Looking for a simple timer circuit

Subject: [DPRG] Looking for a simple timer circuit
From: Mark Crowder MDC1153 at dcccd.edu
Date: Mon Feb 18 11:07:25 CST 2002

Okay, There has been LOTS of discussions about contest timers of late, and it is not the intention of this request to re-spark that discussion.

Is anyone aware of a circuit diagram on the web for a timer circuit that could be made simply and be used out-doors (I am concerned about sunlight affecting the results)?

There where many concerns regarding the timing of contest that don't apply here, so I would like to start with a clean slate.

My thoughts are along the lines of 2 light beams (IR?) with sensors, when the first one is broken, the timer starts, when the second one is broken, the timer stops.  Position these parallel to each other, aproximately 1 foot apart, measure the times, and display them on a large LED display to make them visible (or use beep codes).

The objects being measured differ in size, but I believe a chute 3 feet wide would accomodate all objects, I just don't know about IR out in the sun.  How far about could they be set and be accurate?  Would it be accurate at 6 feet?  What sorts of simple shielding my help?

Thanks in advance.

Congratulations to Clay and Trova, pretty cool navigation processes.

Congratulations to James and JKEK, I like that speed.

Congratulations to Frank and Alice, what a cool looking little robot.  Curious though, how was it going to manage a turn?  Or was it along the line of a quick-trip (straight up, straight back) non-turning robot.  It was cool to see one of those skate-bot hacks in action. 

Mark Crowder

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