Twinkling LED Matrix Schematic Needed

[Boncuk]

That's probably because you used TTL, not CMOS and used to small resistor and too large capacitor values.

Absolutely correct! 40 years ago there were no CMOS ICs. I haven't tried again.

 

[audioguru]

40 years ago there were no CMOS ICs. I haven't tried again.

I started using Cmos about 30 years ago. Then I stopped using 74LSxx TTL about 25 years ago and I have used Cmos ever since.

 

[Boncuk]

That's probably because you used TTL, not CMOS and used to small resistor and too large capacitor values.

Exactly right the first point, not right concerning Rs and Cs. 45 years ago there were no CMOS ICs. I didn't even bother trying later.

 

[Boncuk]

Twinkling LEDs

Big change!

after all the good advises I've tried to make the astables using a CD106 inverting Schmitt-Trigger.

The clocking works well. This way 50 LEDs can be lit with 6 ICs, one for a clock signal oscillator and five clock inhibit oscillators, five ICs for the counters.

Using junk resistors and capacitors they might all be of the same value causing different frequencies which are a MUST for that circuit.

A tolerance of 40% would make the circuit perfect.

Otherwise modify the R and C values slightly for different clock inhibit frequencies.

Hi audioguru, did you have your divorce yet?

 

[audioguru]

Hi audioguru, did you have your divorce yet?

Divorce?
No, I am happily married.
Oh, I divorced power-hungry TTL about 25 years ago.

 

[mindlessmalk]

Hans, were you able to come up with a schematic that works? I played around with the simulator a few times, and could only get to the point where a single random LED would turn on, and stay on until i reset the circuit. I couldn't get them to change without resetting.
You can post the files here and change the extension or something. I never got any emails from you.
Thanks!

Nate

 

[Boncuk]

Twinkling LEDs

Hi Nate,

sad to read that. I sent the files more than one week ago. As I received no return message I assumed that you have received them.

Anyway, I'll try two things: post them here as a *.zip file and resend via e-mail.

The internet band width in Thailand is surely not the best. Additional server failures do the rest for the worst internet connection I know of.

Hans

 

[Boncuk]

Twinkling LEDs

Hi Nate,

here I am again.

Two sets of files - PSEUDO-RANDOM.zip (Basic version with NE 556 and 1 counter)

- PSEUDO-RANDOM-I.zip (Extended version with C-MOS-ICs and 5 counters)

Remark: The reset pin(s) (pin15) of the counter(s) must be tied to GND at all times.

Hans

 

[mindlessmalk]

I got them this time. Thanks a lot! I will check them out tonight.

I am sorry to hear you sent them. I had assumed that you were busy, and I dont want to bother you.
I really appreciate your help though!

I will be sure to post links and pics to my projects when i get into the design phase.
Peace, Happy April 20th
Nate

 

[mindlessmalk]

These are great! I will try to set them up using ISIS so I can simulate the effect. I like the idea of being able to tune the circuit to what I want without buying all those parts!

Thanks a lot for your help, I will let you know when I have something ready.

Nate

 

[muralidhar]

Twinkling LEDs

Hi Nate,

DEAR Hans,

Kindly send me the circuit details of the Twinkling LEDs.

Regards,

Muralidhar