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3 digit 7 segment led counter package?

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Ryan Kremser

Jan 1, 1970
0
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.
 
T

Tom @ HollyLodge

Jan 1, 1970
0
Ryan Kremser said:
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.

3 X 4026 connected to counter chips, and an and gate on the correct OPs to
reset at desired number!
 
R

roma

Jan 1, 1970
0
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.

Easy to build once you have made the PCBs see circuit
http://members.shaw.ca/roma/three digits.html
roma
 
Ryan said:
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.

Dick Smith Electronics.
Kit number K3452 AU$32.50 ea
http://www.dse.com.au/cgi-bin/dse.storefront/3f625a1402cd7c8c2741c0a87f9c06e2/Search/Run

Somewhat cheaper, but it looks the same
Altronics
Kit number K2505 $AU24.95 ea (5 off = AU$22.45 ea)
http://www.altronics.com.au/cat.asp?cat=11&grp=429&id=K2505
 
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Brian

Jan 1, 1970
0
Cheap calculators can be used for this purpose. Pulse the +, 1 and "clear"
lines.
 
B

Bob M

Jan 1, 1970
0
Hi Brian,

This is a pretty crafty idea, but you have to be careful when doing
this. Most keyboard operated devices use a micro and software to
"scan" for depressed buttons. As an example, a keyboard consisting of
16 buttons would have 4 inputs scanning to see if there is a button
depressed connecting it to one of 4 outputs that sequencially are
pulsed.

To actually do what you are suggesting, you would have to install a
gate in place of the button, and ensure that the gate enabling pulse
is long enough to pass the required scanning pulse(s) (1 or possibly
more depending on the key debounce software).

A consequence of the above would be very slow counter operation. The
calculator needs only to respond to human pulsed keystrokes (3 or 4
per second at most?), so it is likely the software is adjusted
accordingly to ensure that bouncy keyboard switches are not an issue.

Cheers from Canada!

Bob Morgoch
 
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Robert Monsen

Jan 1, 1970
0
Ryan Kremser said:
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.

take a look at http://home.comcast.net/~rcmonsen/ for a simple way to drive
a set of 7 segment displays using a PIC uController. Modifying the software
to do this counting (including debounce if necessary) will be fairly easy.
There are apnotes on doing button debounce from microchip.

Regards,
Bob Monsen
 
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Mark van der Eynden

Jan 1, 1970
0
Ryan Kremser said:
Any recommended 3 digit 7 segment counter packages ready to attach into
a circuit? I need to be able to pulse the display and have it increment
by one up to 300, also would need a reset function. Is it recommended
to buy pre made circuit or individual components to assemble myself.
I'll need 6 of these so any help would be appreciated.

Try a 74c926 or thereabouts It is described as a '4-Digit Counter with
Multiplexed 7-Segment Output Drivers'.

http://www.ee.washington.edu/stores/DataSheets/cd4000/74c926.pdf

The hardest part of the exercise will be finding one though, TECS
seemed to have some in stock as I was googling for this information.

Cheers,

Mark
 
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