Where has this forum been all my life?
Long story short, I was HEAVILY into digital electronics from 1979 to the late 80s. Unfortunately, life took over, so I have forgotten many things. plus, I'm old now.
I built prototype of a 3-channel LED chaser with some diodes and transistors. It worked perfectly. Ten I used EasyEDA to design a board. 8 revisions, verified a zillion times and it just didn't work.
Basically, it uses 3 strings of 10 LEDs each, paid out like 1A 1B, 1C, 2A, 2B, 2C, etc. Gives a really cool effects when it runs. Well, WHEN it runs.
So I want to be able to control the speed with a 555 and use a simple counter to count to 3, triggering each channel, then reset and repeat.
That's where I get stuck. I can't for the life of me remember which 74 series TTL chip to use as a counter. I looked through a whole bunch and their data sheets, and my 58 year old brain cells can't remember the simplest thing.
I thought maybe an '148, then I looked at the '390. Then I can't remember if the 3rd "count" would be able to drive 10 LED's then reset the counter.
Or, do I need to use the 4th count to do the reset, but then will there be a noticeable delay in the 'visual'. Getting old is not cool.
So, I'll use the 555 as a timer, whatever chip hopefully someone can recommend, and possibly a one of the low-end TTL, if I need an inverter or something to kick off the LEDs
I hope I explained this well enough.
Thanks for ANYONE who can help this old guy bring back his love of digital!
Mike
Long story short, I was HEAVILY into digital electronics from 1979 to the late 80s. Unfortunately, life took over, so I have forgotten many things. plus, I'm old now.
I built prototype of a 3-channel LED chaser with some diodes and transistors. It worked perfectly. Ten I used EasyEDA to design a board. 8 revisions, verified a zillion times and it just didn't work.
Basically, it uses 3 strings of 10 LEDs each, paid out like 1A 1B, 1C, 2A, 2B, 2C, etc. Gives a really cool effects when it runs. Well, WHEN it runs.
So I want to be able to control the speed with a 555 and use a simple counter to count to 3, triggering each channel, then reset and repeat.
That's where I get stuck. I can't for the life of me remember which 74 series TTL chip to use as a counter. I looked through a whole bunch and their data sheets, and my 58 year old brain cells can't remember the simplest thing.
I thought maybe an '148, then I looked at the '390. Then I can't remember if the 3rd "count" would be able to drive 10 LED's then reset the counter.
Or, do I need to use the 4th count to do the reset, but then will there be a noticeable delay in the 'visual'. Getting old is not cool.
So, I'll use the 555 as a timer, whatever chip hopefully someone can recommend, and possibly a one of the low-end TTL, if I need an inverter or something to kick off the LEDs
I hope I explained this well enough.
Thanks for ANYONE who can help this old guy bring back his love of digital!
Mike