I'll start off by saying I know next to nothing about electronics. With that said I'm fairly logical and can follow things pretty easily, I'm handy and I can solder just fine.

I'm looking to build a scoreboard used for shuffleboard. What I want it to do is have two separate teams, each with a double digit display which count to 21 then resets. The counting is controlled by a button, which you press once for each point scored. I want to build this as cheap as possible.

I found online a "counter kit" which counts to "99". With no reset. It was 11 dollars so i figured why not buy it as a starting point since its got a lot of what I want for cheap and without having to do any work. I thought just resetting the power might reset the count to "00" but it doesn't.

I don't really NEED the counter to stop at 21 if i can get it to reset to "00". (Plus with not setting the limit, I could use it for a different score total or a different sport) So my question is: What do I have to do/get to easily make this scoreboard reset to zero?

 

Which kit did you buy?

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Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

LED 2-DIGIT COUNTER KIT | AllElectronics.com

 

You can find the kit at the all electronics .com website.
Google "LED 2-Digit Counter Kit" the site should be the first link that pops up.

 

No schematic, what are the part numbers on the 3 ICs?

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com/

 

The one is CD40106BCN
The other two are HCF4026BE

 

The HCF4026BE (4026) pin 15 is the reset pin, active high. If they are connected together in the circuit and go to an RC circuit, you only have to pull it high momentarily to reset to 00. Use a 1k (270<1k<4.7k) resistor to limit the current so nothing blows up.

The best way to conduct this experiment is to put the 1K momentarily between pin 15 and 16 of one of the 4026's (shouldn't matter which 4026).

If this works, you can extend it to a switch. Remember that one of your new wires is the + supply and keep it from the - supply accordingly.

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de KI6RWX

 

Look here: Afficheur pour jeu de pala

 

Ive attached pics of the circuit board. On the left you see the three wires for power. The yellow on the bottom being the - the middle red being the +. Do you know what the top red wire is for? The instructions coming with the kit instructed to cut it.

Attached Thumbnails

   

 

I tried the experiment but it didn't do anything. I probably didn't do it right or something. Basically I have to create a connection with a momentary button from the positive supply to pin 15?

 

Basically that's correct.

I looked at your pictures and they didn't hook it up the way I expected. Was worth a try. I'll study the pictures some more.

[edit]I looked at the photo. Here's what you can do: Make a parallel combination of a 100k resistor and a 10 nF (0.01 uF) capacitor. Remembering that this is static sensitive, lift both pins 15 out of their holes. (Watch, the ICs are the other way around, and avoid damage to the fine traces between pins 14 and 15). Connect them together, and also to one end of the assembly you just made. Connect the other end to 0V (pin 8 is handy). This is your 'reset' pin.

The bare necessities would just put a push button between +V (pin 16) and this reset pin, but I would put 1K resistor on each wire as it leaves the board to protect against static electricity and short circuits. Your call.

The red wire is not +V as it has a diode in it so the board could work on AC. (The second red wire could have been used as another power pin.)[/edit]

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de KI6RWX

 

Sounds good. I think I will give this a try. Thanks very much for all your help mneary. Very much appreciated!

 

btw, that looks like a sweet little counter. Maybe I'll wander over to All sometime this weekend and pick up a few.

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de KI6RWX

 

After looking at it closely I am a little nervous about butchering this and messing something up. Pulling out the single pin being my main worry. I wonder if this is my only option tho. If so I guess eventually I'll have to take the plunge. Anyone else have any thoughts or ideas in the mean time?

 

If you prefer you can cut the traces underneath leading to the pins.

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de KI6RWX