# Electronic timer question

Discussion in 'General Electronics Discussion' started by ntom, Sep 23, 2012.

1. ### ntom

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Sep 23, 2012
I have an electronic scoring system. It is driven from two mechanical switches, each linked to a lamp, red on one side & green on the other.

When both switches are activated at the same time (or within a very short time frame) both lamps are illuminated. Outside of this time frame, the lamp corresponding to the first switch depressed, is illuminated, the second switch being too late is ignored.

I want to construct a calibration tool, enabling me to reasonably accurately gauge the time at which simultaneous activation can or can't occur.

It's not necessary to get an accurate measure, i'd be happy manually trying varying time settings to arrive at a value. This is a low voltage (<12v system).

I have some electronics experience, but it's >30 years ago....!

Can anyone put me on the right track here.....would this be a PIC project...?

A few suggestions would be appreciated then I can go read up before deciding whether this is something I'd be capable of constructing!!

Many thx.

2. ### wingnut

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Aug 9, 2012
My first reaction would be to drop two balls simultaneously from different heights onto the switches (directed by funnel and tubes). The time for each ball falling can be calculated by s = .5 x 9.8 x t x t where s is height in m, and t is time in s.

Or t = square root of (2 x s /9.8)....... or square root of s/5

Last edited: Sep 23, 2012
3. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
Yes, like most things electronic, a uC makes this a trivial task. If you have not worked them yet I would suggest looking into Picaxe for a near painless and by far the cheapest entry into uC-s.

Chris

4. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
I Knight you Sir Wingnut Newton.

When I first read this I thought doable but mostly funny. However, if this is an audience related game it would be visually cool! I can think of more practical ways of measuring the time though. I just like the visuals, but then I like miniature golf with windmills.

Chris

5. ### wingnut

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Aug 9, 2012
Thanks Chris

In my next post I will explain how to build a microcomputer using only pipe cleaners and a lemon

6. ### Osh

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Sep 22, 2012
Ooooh, I like the dropping balls, that would be cool.

In lieu of that, what about something done with a 555 that triggers an open relay after a certain period of time?

7. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
Please explain the purpose of this. I would think that game logic would dictate If one switch is closed prior to the other, no matter how short the period between the two are, the second switch closure should be ignored entirely. Perhaps I misinterpret your statement?

I think you should post you existing circuit.

Chris

8. ### Osh

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Sep 22, 2012
Chris - were you asking me to post my existing circuit? If so, I don't have one, I was only offering a suggestion to the OP.

My guess is if two players "buzz" in at the same time, there may be some sort of shoot-out situation. Maybe they bid on who gets to answer first, highest bid wins, kinda situation... That would eliminate reaction time from the equation... Or maybe it's a game geared towards handicapped individuals... I didn't ask, and assumed OP had a reason for close enough together would trigger both....

9. ### CDRIVEHauling 10' pipe on a Trek Shift3

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May 8, 2012
I think that was a brain fart on my part. I was hoping the OP would post the existing circuit.

Chris