[b]HELP! how to build an event counter... [/b]

[poch]

hi, I need to built an event counter, the idea is that a sensor detects something and count the number of times it was detected and display the number of times... all of this using a sensor, TTL,Op-amp, and display!

I'll appreciate your help!

 

[nettron1000]

How many events will you be counting ?
What will be the application for the circuit exactly ?
What IC's do you have on-hand ?
What type of sensor do you have in mind ? e.g. infrared, hall effect, photoresistive, etc.
What will be the sensing distance ? this will have an effect on the type of sensor you choose.

 

[poch]

thanks for our reply,

I need to count 9 times max, the distance won't matter, i'm thinking of an infrarred sensor... but I don't have an idea of how is everything connected...

 

[nettron1000]

Use this .....

**broken link removed**



To drive this....

**broken link removed**

Connect to pin 14.

 

[kc_purcell]

8254/82C54 Programmable Interval Timer can be easily set up to be an event counter.

Harris semiconductor 82C54 Datasheet: https://www.electro-tech-online.com/custompdfs/2003/10/82C54_datasheet.pdf
Intersil 82C54 Datasheet: https://www.electro-tech-online.com/custompdfs/2003/10/fn2970.pdf

 

[bubba99723smith]

4 or 5 digit event counter

I also have a need for an event counter except in my case I am looking to count the pendulum swings on an antique clock after repairing it. By counting the teeth on the wheels and doing some simple math I am able to tell how many beats of the pendulum will give the correct speed of the clock. The problem is I don't want to sit for an hour with a stop watch and count the beats over an hour period. This would necessitate a 4 or 5 digit display while it looks as though this IR LED would do the job of sensor. Any help for schematic for this project?

 

[henrybot]

If you value your time, then sit with the stopwatch!
You'll spend over an hour messing with buying parts, prototyping, and setting it up.
Unless you would use this circuit for other clock repairs?

And why couldn't you just start your stopwatch when the clock hits 1pm. At 2pm, you can figure how far off the clock is.

-mike

 

[bubba99723smith]

Repairing clocks is a hobby at the moment that may turn into something more in retirement. There are and will be many clocks.

Typically the clocks run for ten days (or more). Over the period of an hour the long term effect of an adjustment is not readily noticeable. Also, there may be typically 80 beats per minute so that is some pretty intense counting over the period of an hour. After a slight turn of the regulating nut on the pendulum then the process starts all over again to see what the results of the adjustment are.

There are commercial units that sell for about $300 specifically to do this. I thought it would be fairly easy and possibly cost effective to build a device to do this, especially since I have a bit of electronics background. It has been many years though. The commercial units may be the way to go since I believe that you can basically tell it what the beats per minute should be and it can tell on the fly if you are getting that. I thought it would be fun to build something instead and save some money.

 

[blueroomelectronics]

Hmm might be a fun use for my Dragonfly kit. And it's got a 32,768Hz crystal timebase and is a six digit LED display.
10 days is 864,000 seconds so it'll just fit
**broken link removed**
The Dragonfly, the connector in the upper left corner is RA4 (a TIMER0 input)

 

[bubba99723smith]

Gettiing late, EST, must sleep! Will check this link out.

 

[blueroomelectronics]

It sounds like there could be a market for this, would make an interesting project as the Dragonfly is microcontroller based it would allow for a very flexible design.