Up / Down Counter with relay output

[jmb4370]

I have seen plenty of circuits with counters and multiple linked 7 segment LED displays, either using the 74LS192 (up/dn counter to BCD) into the 74LS48 (BCD to 7 seg LED), or the CMOS chips like the 4510 (up/dn counter) into the 4511 (BCD to 7 seg LED). Is one set better, or is it just personal preference, and chip availability?

When the counter is counting down and reaches 0, how do I get this result available as an output for a relay or a trigger for something else?

When the counter is counting up from 0 to the set amount, is getting this output available done the same way as with the count down to 0?

Would this be any easier to do with CMOS chips like the 4510 (up/dn counter) into the 4511 (BCD to 7 seg LED)?

It almost seems that some other chip is needed to constantly be comparing the curent state of the outputs of the 74LS192 (or 4510) counter to either 0 or the upper set amount.

I would like to make this up/dn counter with discrete chips first, and then do the same after learning PIC programming.

(I am not a student, but a mechanical engineer and electronics hobbyist who wants to learn more).

Thanks for everyones anticipated help.

Michael

 

[silvarblade]

I have seen plenty of circuits with counters and multiple linked 7 segment LED displays, either using the 74LS192 (up/dn counter to BCD) into the 74LS48 (BCD to 7 seg LED), or the CMOS chips like the 4510 (up/dn counter) into the 4511 (BCD to 7 seg LED). Is one set better, or is it just personal preference, and chip availability?

When the counter is counting down and reaches 0, how do I get this result available as an output for a relay or a trigger for something else?

When the counter is counting up from 0 to the set amount, is getting this output available done the same way as with the count down to 0?

Would this be any easier to do with CMOS chips like the 4510 (up/dn counter) into the 4511 (BCD to 7 seg LED)?

It almost seems that some other chip is needed to constantly be comparing the curent state of the outputs of the 74LS192 (or 4510) counter to either 0 or the upper set amount.

I would like to make this up/dn counter with discrete chips first, and then do the same after learning PIC programming.

(I am not a student, but a mechanical engineer and electronics hobbyist who wants to learn more).

Thanks for everyones anticipated help.

Michael

you need to tell the desired number(counting up or down) that you want to get the relay energised on. cause you will need a single o/p for the relay.You will have to make a seperate logic ckt for the o/p expression.

 

[jmb4370]

Hi silvarblade, et al-

Thanks for the reply, but first off, what is "o/p", dies it refer to "output"?
Any comments of whether this is all easier with the TTL or the CMOS chips?

When the desired finish number is entered for the countdown, or countup section of the counter itself, will this finish number have to be reentered for the logic test circuit also?

Do you have any more insight or suggestions for this logic circuit to test the finish point and provide the output?

 

[jmb4370]

Hi blueroomelectronics (Bill),

You said in another post: "I've not had to use TTL as building blocks for ages" are you referring to all the 74xxxx series IC's, or just the older true TTL series?

Throughout the posts in this forum, many of the circuits show 74xxxx IC's being used. Are these just older style circuits (or designers)?


Any further ideas on how to logic test to get the "alarm output" at the end of the countdown (or countup) period (ie: at the end of the countdown or countup, a bell will ring)?

 

[blueroomelectronics]

Microcontrollers and PLDs have pretty much replaced discreet TTL for the past 20+yrs. The original IBM PC was built with TTL logic chips and cost a fortune. The old TTL clocks are fun for some to build if you like soldering lots of wires but even a simple microcontroller clock is far more flexable. Some TTL ICs have started to disappear too. If you looked at the Dragonfly schematic I've used one CMOS IC the CD4022 Johnson counter as it was perfect for 1. saving a couple I/O pins 2. making it impossible to drive more than one digit at a time. I could have easily not used the 4022 and stayed with just the PIC.

 

[somasiri]

I want a up/down counter circuit to count 0-99 and with reset facility. Please help me. somasiri

 

[ericgibbs]

I want a up/down counter circuit to count 0-99 and with reset facility. Please help me. somasiri

hi,
Look at the HEF40192 BCD 4bit Up/Down counter.