help with led sequencer

Ubergeek63 said:

You forgot what he is trying to do: keep the lower lights lit until the cycle restarts.

Click to expand...

The simple CD4017 circuit lights only one LED at a time.
If the 10th output is connected to the reset pin then the moment it gets to 10 it resets to light the 1st LED and misses lighting the 10th LED.

That is why using a shift register is recommended because it can light more than one LED.

on1aag said:

Hi Mazikowski,

I know it's tempting to use the circuit with the CD4017
because it does it all in one box but if you want a led
bar it's getting rather complicated and you're gonna get
more trouble than you can handle.
Stick to the circuit with the shift register, if you add
a second CD4015 you'll get 16 outputs.
And if you add transistors you can drive as many leds
as you want.

https://www.electro-tech-online.com/attachments/light-chaser-984-gif.13410/

on1aag.

Click to expand...

Is it necessary
to use Schmitt trigger NAND gates (CD4093), or can normal NAND gates (CD4011) be used?

Hi Mazikowski,

It's necessary to use A CD4093, otherwise the oscillator
won't work and it's also better for the power-on-reset.
Oscillator first gate from left and power-on-reset third
gate from left.
But if you insist on using a CD4011 you'll need to replace
the oscillator with the one in your circuit, it should work
equally well.

on1aag.

on1aag, I cant tell what values your caps and variable resistor are. I am looking at using a single 4015 for driving 2 individual strings of led's. 3 strings of 3 led's in series on each 1/2 of the 4015 for turn signal sequencers. Running on 13.5 volts. If your using the schmitt nand's as a clock trigger, I could use one set for both sides right?. And same for the power-on-reset? I have very limited space on my board. I was going to use 4017's, but cant fit 2 with a 555 also. However I can fit a 4015 and a 4093. I also like the part of them all being lit until it reaches the end. thanks