Difference in mechanical switch versus electronic switch

General timing system discussions.
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PWD
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Difference in mechanical switch versus electronic switch

Post by PWD »

I have a IAC timer with a electronic starting switch and I have always been suspicious if it was accurate. Seemed like the same time came up too often.

So I decided to also connect our NewBold timer. It has a mechanical timer. What I found was the NewBold timer was about .0150 slower than the IAC timer. But not super consistant. It would fluctuate as much as a 100th of a second..

I attribute this to the longer time for the mechanical switch to trigger versus the electronic switch.

Does 150th of a second sound reasonable?

This experiment has made me more comfortable in the IAC timer. But I also believe a mechanical switch is not accurate enough to really determine who wins a race when the winning times are within 100th of a second which would be a typical situtation.
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Cory
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Re: Difference in mechanical switch versus electronic switch

Post by Cory »

PWD wrote:But I also believe a mechanical switch is not accurate enough to really determine who wins a race when the winning times are within 100th of a second which would be a typical situtation.
For my experiments years ago, I used what I would call a mechanical switch. The same swift movement that made the pins drop also opened a circuit by opening a small knife switch. And I was able to get 10-milliseconds spreads across as many as eight heats.

I think it depends on the mechanism.
Doug-in-the-woods
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Re: Difference in mechanical switch versus electronic switch

Post by Doug-in-the-woods »

not sure what an 1ac timer is but an electronic switch is faster switching, it inputs into the timer a "clean" glitch free signal. A mechanical switch will cause what is referred to as switch bounce.
A simple switch that is redly available from local Radio Shack is called a HALL EFFECT switch. just mount to a stationary point on start gate and mount a magnet on the start gate so when the start gate is open the HALL EFFECT switch is turned on.
these switches are use in electronic ignition on your car so they are very fast in switching from off to on.
I plan on using them on my new start gate that I am building w/ a start tree.
The start gates will be participant actuacted and a red light is a real possibility.
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