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7 Segment LED Counter

A

Animesh Maurya

Jan 1, 1970
0
I am designing a 7 segment LED counter which is using 74LS90 as BCD
counter and 74LS47 as BCD to 7-Segment Decoder/Driver.

Counter is intended for counting no. of interruptions between an IR
LED and IR sensor module (TSOP1738).

Interruption so caused triggers a 555 monostable whose output is
connected to the counter (pin 14).

I need to know is the above arrangement good enough to make counting
upto say 20Hz or so,
assuming output of the monostable in of the order of few
milli-seconds.

If there is any more effective arrangement please suggest it.

Thanks

Animesh Maurya
 
T

Thomas C. Sefranek

Jan 1, 1970
0
Animesh Maurya said:
I am designing a 7 segment LED counter which is using 74LS90 as BCD
counter and 74LS47 as BCD to 7-Segment Decoder/Driver.

Counter is intended for counting no. of interruptions between an IR
LED and IR sensor module (TSOP1738).

Interruption so caused triggers a 555 monostable whose output is
connected to the counter (pin 14).

I need to know is the above arrangement good enough to make counting
upto say 20Hz or so,
assuming output of the monostable in of the order of few
milli-seconds.

It will work, but you don't need the 74S90, the plain-jane 7490 will easilly
do 20 Hz.
And to make it more compatable with the decoder driver, use the 74LS90.
If there is any more effective arrangement please suggest it.

There are expensive LEDs with the decoder and counter built in!
745-0009 TIL-306A Counter+Dec w/dp
Thanks

Animesh Maurya


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| __O Thomas C. Sefranek [email protected]
|_-\<,_ Amateur Radio Operator: WA1RHP
(*)/ (*) Bicycle mobile on 145.41, 448.625 MHz

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A

Ardent

Jan 1, 1970
0
X-No-Archive: yes

It will work, but you don't need the 74S90, the plain-jane 7490 will easilly
do 20 Hz.
And to make it more compatable with the decoder driver, use the 74LS90.

He does not need the 555 too. I made a counter in the past,something
like this to count radiator fins without the 555.
 
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