clocking start and stop times for runners

[DaveK]

I NEED HELP! I WOULD LIKE A CIRCUIT TO RECORD A RUNNER'S TIME.


The times would not necessarily have to be accurate, but consistent to
some degree. This information would be used to evaluate my son's
speed and in-turn, use this information to see if any certain
improvement in his running technique or training regiment would make
any difference in his times. Nothing has to be fancy. I could rig up
any type of fixture to line up any sensor that may work with this kind
of application. Below are some suggestions/questions which I don't
have a clue would even apply.


1. Would starting the clock (switch button & the word go) and some
sort of sensor to stop the clock work? Better yet, a sensor for the
player to break a beam to start and stop the clock. This would take
out the difference in time from a runner's hesitation.

2. What about infrared sensor?

3. If the runner were to run in a low-light setting, could a
phototransistor and an incandescent bulb be used?

4. Are any circuits available in other devices such as clocks,
appliances, etc., that could be used in conjunction to limit labor,
parts or cost?

5. Is this even doable? I have a fair amount of knowledge with
electronics and component, but need a lot of help.


Any suggestions would be greatly appreciated.
Dave K

 

[Rich Webb]

[snip...snip...]

1. Would starting the clock (switch button & the word go) and some
sort of sensor to stop the clock work? Better yet, a sensor for the
player to break a beam to start and stop the clock. This would take
out the difference in time from a runner's hesitation.

Reaction time is a factor in this. I'd use a microcontroller to fire a
piezoelectric beeper at the start (what do the real track and field
guys use, something like beep-beep pause beep-beep pause beeeeeeeeep?)

2. What about infrared sensor?

A laser pointer to photo-transistor to trigger the stop. A modulated
laser would have more immunity to false signals but if the receiver
was in a shielded tube (paper towel tube, painted flat black on the
inside) you could probably use a CW gizmo.

Radio Shack should still carry "logic level" beepers (built-in driver)
and the photo-transistors. IIRC, their peak sensitivity is IR but a
red laser pointer may be enough to turn one on.

3. If the runner were to run in a low-light setting, could a
phototransistor and an incandescent bulb be used?

Narrow beam flashlight would probably do it, too.

4. Are any circuits available in other devices such as clocks,
appliances, etc., that could be used in conjunction to limit labor,
parts or cost?

Something like a Basic Stamp (www.parallax.com) would do the trick if
you don't have a drawer full of assorted microcontrollers.

5. Is this even doable? I have a fair amount of knowledge with
electronics and component, but need a lot of help.

Should be easy if the start and finish are reasonably close. If
they're 26 miles and change apart, Hmmm ... have a cell phone on
speaker set up at the start site to broadcast the starting beeps?

 

[Lord Garth]

I NEED HELP! I WOULD LIKE A CIRCUIT TO RECORD A RUNNER'S TIME.


The times would not necessarily have to be accurate, but consistent to
some degree. This information would be used to evaluate my son's
speed and in-turn, use this information to see if any certain
improvement in his running technique or training regiment would make
any difference in his times. Nothing has to be fancy. I could rig up
any type of fixture to line up any sensor that may work with this kind
of application. Below are some suggestions/questions which I don't
have a clue would even apply.


1. Would starting the clock (switch button & the word go) and some
sort of sensor to stop the clock work? Better yet, a sensor for the
player to break a beam to start and stop the clock. This would take
out the difference in time from a runner's hesitation.

2. What about infrared sensor?

3. If the runner were to run in a low-light setting, could a
phototransistor and an incandescent bulb be used?

4. Are any circuits available in other devices such as clocks,
appliances, etc., that could be used in conjunction to limit labor,
parts or cost?

5. Is this even doable? I have a fair amount of knowledge with
electronics and component, but need a lot of help.

You neglected to say the limits of the timer. I would guess less than
one hour should do.

Are you okay with purchasing a timer or do you prefer to build the device?

The photogate should always be a modulated light source so that external
interference can be filtered out. This being the case, an incandescent lamp
would
be a poor choice.

An Ir sensor detects over too broad of an angle so this too is a poor
choice.
If you remove the fresnel lens, the detection angle would be narrower but it
is still a passive sensor, meaning it would detect any heat source.

 

[DaveK]

You neglected to say the limits of the timer. I would guess less than
one hour should do.

Are you okay with purchasing a timer or do you prefer to build the device?

The photogate should always be a modulated light source so that external
interference can be filtered out. This being the case, an incandescent lamp
would
be a poor choice.

An Ir sensor detects over too broad of an angle so this too is a poor
choice.
If you remove the fresnel lens, the detection angle would be narrower but it
is still a passive sensor, meaning it would detect any heat source.- Hide quoted text -

- Show quoted text -

Thank you for getting back to me.
Yes, I am ok with purchasing a timer, but I am not sure how this would
tie in. I not to smart!!
Is there any other divice or sensor that may work for the stoping and
starting the clock besides a manual push off and on swith.
The distance is 40yrd. (40yrd Dash)
Can it be accomplished without the use of a microcontroller?

 

[Lord Garth]

Thank you for getting back to me.
Yes, I am ok with purchasing a timer, but I am not sure how this would
tie in. I not to smart!!
Is there any other divice or sensor that may work for the stoping and
starting the clock besides a manual push off and on swith.
The distance is 40yrd. (40yrd Dash)
Can it be accomplished without the use of a microcontroller?

By purchasing a timer, you eliminate any need to build with a
microprocessor.
You will need to find a timer, cooking timers usually count down rather than
up,
that you can hack. You will need to be able to solder wires to the timer
trigger.

An optical gate will require electronic construction skills. A likely
circuit will include
a 555 timer IC to create a pulsing light beam for the transmitter and
another to
create a missing pulse detector for the receiver.

Perhaps the easiest approach is to get the optical beam sensors used on
garage
doors. Though this isn't the least expensive plus the operating voltage
might not
be DC.

I once found an all in one unit that used a mirror at the opposite side and
provided
a relay closure for the output. This you would normally connect to a bell
to sense
people crossing some area. I'd tell you the name but it is installed at an
office a
few miles from here. Perhaps I can go there this week and write further.

 

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i want the design for a timer with a pulse delay of 1min and 1 usec
at freq 1 Mhz