Hi.
Back in the 1980's I built a couple of simple LED sequencers and taped them to my son's roller boots so that he "looked cool" at the roller disco. I'm trying to build a similar circuit but I can't now remember how I did it. The key thing about the circuit is minimal component count.
What I can remember is that I used a CD4049 hex inverter chip and a few capacitors and high value resistors to connect the inverter in a ring. The 6 leds were driven directly by the inverter outputs.
Can anyone help me with this circuit, please? I expect it is a recognised standard circuit but I can't find anything on the web.
Thanks,
Chris.

 

The popular chip or at least one of the popular chips using discrete components is the 4017 and a simple Google of LED Chaser Circuits should yield a few dozen hits. Here is an example of Google.

Ron

 

The popular chip or at least one of the popular chips using discrete components is the 4017 and a simple Google of LED Chaser Circuits should yield a few dozen hits. Here is an example of Google.

Ron

Thanks for the reply, Ron.
The problem with the 4017 is that it needs an oscillator to drive it whilst the 4049 was self driving. I think the output of one inverter was connected to the next with a CR delay circuit between them and the last was connected back to the first. I think I'll set something up on a breadboard and fiddle until it works. The chips aren't too expensive

Chris

 

The CD4049 family are Hex Inverting Buffers and yes, two of the six on the chip can be configured as a square wave oscillator to drive a few LEDs and a few more LEDs added using the remaining inverting buffers. All you need is a few components like a capacitor and resistor. If simple is good then using a CD4049 should work out fine. IC 4049 Square wave oscillator generator is a good example.

Ron

 

You can use this circuit (below) but adapt it to using a CMOS inverter like the CD4049 as shown in the hand-drawn circuit fragment further below. NOTE: This will work with any odd number of inverters.

 

Start here:

Then, replace the MOSFETs with hex inverter stages. With an odd number of stages, things will walk around the circle.
With a CD4049, the LEDs will wander up and down.
With a CD40106, the LEDs will snap on and off.
With MOSFETs you can have much brighter LEDs

ak

 

Another approach is to use one stage of a CD40106 as an oscillator and the other five stages as inverting and non-inverting drivers. Six LEDs will alternate in two groups of 3.

ak