Need Help on how to build 7 - Segment Display circuit with Series of LED's

[barbaro]

Hi mister_rf

I finally have it working, it's just that my breadboard doesn't do that much proper contact with my pushbutton switch pins which still do a little bouncing but, works properly when I do press the switch in. Nevertheless, I used 47k resistor and 47nF capacitor just to let you know.

Now, I need to do the second digit circuit and connect it with the first one and then create another two digit for the other team scoring.

After that maybe you can help me for the buzzer/shot clock circuit again.

I really appreciate your big help on this project although I only spent a little bit of time every time I am free.

Thanks,
Barbaro

 

[barbaro]

Hi mister_rf

I finally have it working, it's just that my breadboard doesn't do that much proper contact with my pushbutton switch pins which still do a little bouncing but, works properly when I do press the switch in. Nevertheless, I used 47k resistor and 47nF capacitor just to let you know.



Now, I need to do the second digit circuit and connect it with the first one and then create another two digit for the other team scoring.

After that maybe you can help me for the buzzer/shot clock circuit again.

I really appreciate your big help on this project although I only spent a little bit of time every time I am free.

Thanks,
Barbaro

Hi mister_rf,

I found this schematic that you sent me a while back. Could you please let me know if you can revise the curcuit using the counter IC to 74HC192 instead of the CD4510?

I guess the CD4510 is a differnet pinouts with the one I have now (74HC192).

Please and thank you again, see attached.

 

[mister_rf]

If we combine the schematics we may obtain this (I have included two version for the debouncing circuits):

 

[barbaro]

mister_rf

Thanks for the schematic again with the two options for the debouncing.

As I've mentioned earlier, would you be able to also include the "shot clock circuit" using the 74HC192 instead of the CD4510 IC?

barbaro

 

[mister_rf]

See the new diagram. I hope it’s free off design/drawing errors (because I also need to find some free time and internet access in this period of year, I’m traveling around Europe :-D).


Normal operation
1. Buttons 1 & 2 for UP and DOWN counting sequence
2. Button B3 = RESET
3. Switch S1 OPEN
4. Button B5 are disable for S1 OPEN
5. Button B4 (load) not to be used


24 seconds timeout
1. Switch S1 closed
2. Use B3 for a RESET (if necessary, like in the situation alarm ON condition activated)
3. Press button B4 for load ‘’24’’ on the display
4. Press button B5 to start automatic counting down sequence when necessary.
5. End of automatic counting, display=‘’00’’, alarm triggered, T1 ON, LED light& buzzer activated
6. At some convenient moment possible to reset the alarm by pressing B3 (on display = 00)
7. Open S1 to change for the normal UP/DOWN counting sequences.
PS: during this period do not press buttons B1 & B2

In practice, first need to adjust the variable resistor in order to obtain the accurate 1Hz pulse. This may require spending some time as it’s necessary to compare the 24 pulses automatics counting down with an external clock, and start readjusting (+/-) in small steps the variable resistor end of each time period. Multiple rounds may be necessary to be completed for this task until the necessary accuracy are obtained.


f= ~1/RC

R= ohms
C= farads
For 1Hz we may use
C=10uF= 10* 10^-6F= 10 ^-5 F
R=100k=10 ⁵ohms
And because electrolytic capacitors value typically have very loose tolerances, about +100% / -50% need to adjust resistor value to obtain 1Hz pulses.

The alarm signal may trigger a buzzer alarm, relay, LEDs, so I have placed temporary in the diagram two NPN transistors (to be replaced by a NPN darligton type).

 

[barbaro]

Hi Mister_rf,

Hope all is well with you enjoying the travel around Europe.

Thanks so much for finding time in providing me this schematic. I noticed we've added CD4013 Dual D Flip-flop in the circuit. I will pick-up all the things needed and will start putting together.

This will probably take me a while but, it will also give you time to enjoy your travel by me not to bother you for sometime... haha.

If I have any questions at all.... I will let you know then.

Thanks so much again.

Barbaro

 

[mister_rf]

I have reconsider some details for the above circuit. Need to change some connections in order to stop clock after 24 pulses and display ‘00’ end of the timing.
The old version create a small glitch end of the counting sequence and reset the display to ‘99’.

 

[mister_rf]

Minor changes of the circuit diagram. See the 24 seconds count down clock tested here: