One second PAUSE in 18 Stage LED Sequencer?

L

locator299

Guest
I was looking at Bill Bowden's 18 Stage LED Sequencer circuit at:

http://ourworld.compuserve.com/homepages/Bill_Bowden/page5.htm

(using cascaded 4017 decade counters) and I had a question about its
operation - actually, about the SMOOTHNESS of its operation.

It looks like we would have a smooth blink rate from LED 1 through LED
9, a pause during second #10, then, starting at second #11, LEDs 10
through 18 would light up.

Is that correct or am I looking at this wrong?

I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

Will Bill Bowden' s circuit do that - or does anyone know a better
circuit?

Thanks,

Keith
 
"locator299" <locator299@verizon.net> wrote in message
news:1139802147.693774.190730@g43g2000cwa.googlegroups.com...
I was looking at Bill Bowden's 18 Stage LED Sequencer circuit at:

http://ourworld.compuserve.com/homepages/Bill_Bowden/page5.htm

(using cascaded 4017 decade counters) and I had a question about its
operation - actually, about the SMOOTHNESS of its operation.

It looks like we would have a smooth blink rate from LED 1 through LED
9, a pause during second #10, then, starting at second #11, LEDs 10
through 18 would light up.

Is that correct or am I looking at this wrong?

I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

Will Bill Bowden' s circuit do that - or does anyone know a better
circuit?

Thanks,

Keith
Click to expand...
There is indeed a very small pause during second 10, but it is (way) less
than a microsec (I haven't looked up the 4017 datasheet). The main clock
advances the right counter which activates pin 11. When this pin goes high
it enables the clock for the left counter. If at this moment the clock is
still active (high) the left counter will (almost) immediately see a rising
edge on its clock input and advance one step. So there will be no visible
pause if the clock high-time is a bit longer than the propagation delay of
the right counter (from clock to pin 11). In Bill Bowden's circuit this
condition is largely met.

For your application you could use pin 9 of the left counter to block the
clock by connecting it through a diode to pin 2 of the 555 (anode to pin 9).
This will stop the oscillator. To get things going again you could toggle
the power or add a reset switch (4017 pins 15 to gnd).

--DF
 
On 12 Feb 2006 19:42:27 -0800, "locator299" <locator299@verizon.net>
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.
Click to expand...
---
Do you want the 16th LED to stay on at the end of the sequence or to
go off?

--
John Fields
Professional Circuit Designer
 
"John Fields" <jfields@austininstruments.com> wrote in message
news:6p71v1lj20hj90topjva2vn7i3k4j8q29a@4ax.com...
On 12 Feb 2006 19:42:27 -0800, "locator299" <locator299@verizon.net
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

---
Do you want the 16th LED to stay on at the end of the sequence or to
go off?

--
John Fields
Professional Circuit Designer
Click to expand...
The OP said "STOP after the 16th LED was done" so I suppose this means off.

--DF
 
On Mon, 13 Feb 2006 16:49:58 +0100, "Deefoo" <nonono@wonttell.com>
wrote:

"John Fields" <jfields@austininstruments.com> wrote in message
news:6p71v1lj20hj90topjva2vn7i3k4j8q29a@4ax.com...
On 12 Feb 2006 19:42:27 -0800, "locator299" <locator299@verizon.net
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

---
Do you want the 16th LED to stay on at the end of the sequence or to
go off?

--
John Fields
Professional Circuit Designer

The OP said "STOP after the 16th LED was done" so I suppose this means off.
Click to expand...
---
Yes, but rather than suppose, I'd like to know for sure.


--
John Fields
Professional Circuit Designer
 
John Fields wrote:

On Mon, 13 Feb 2006 16:49:58 +0100, "Deefoo"
nonono@wonttell.com
wrote:


"John Fields" <jfields@austininstruments.com> wrote
in message
news:6p71v1lj20hj90topjva2vn7i3k4j8q29a@4ax.com...
On 12 Feb 2006 19:42:27 -0800, "locator299"
locator299@verizon.net
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

---
Do you want the 16th LED to stay on at the end of the sequence
or to
go off?

--
John Fields
Professional Circuit Designer

The OP said "STOP after the 16th LED was done" so I
suppose this means off.

---
Yes, but rather than suppose, I'd like to know for sure.
Click to expand...

Thank you for your help. Yes, I wanted to press a button to start the
sequence, have LEDs 1 thru 16 light up (in sequence) and then STOP the
sequence automatically after the 16th LED has lit up.

locator299


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On 16 Mar 2009 13:30:53 GMT, locator299_at_verizon_dot_net@foo.com
(locator299) wrote:

John Fields wrote:

On Mon, 13 Feb 2006 16:49:58 +0100, "Deefoo"
nonono@wonttell.com
wrote:


"John Fields" <jfields@austininstruments.com> wrote
in message
news:6p71v1lj20hj90topjva2vn7i3k4j8q29a@4ax.com...
On 12 Feb 2006 19:42:27 -0800, "locator299"
locator299@verizon.net
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

---
Do you want the 16th LED to stay on at the end of the sequence
or to
go off?

--
John Fields
Professional Circuit Designer

The OP said "STOP after the 16th LED was done" so I
suppose this means off.

---
Yes, but rather than suppose, I'd like to know for sure.


Thank you for your help. Yes, I wanted to press a button to start the
sequence, have LEDs 1 thru 16 light up (in sequence) and then STOP the
sequence automatically after the 16th LED has lit up.
Click to expand...
---
That was over three years ago!

Do you still want a circuit?

JF
 
locator299

-------------------------------------
John Fields wrote:

On 16 Mar 2009 13:30:53 GMT, locator299_at_verizon_dot_net@foo.com
(locator299) wrote:

John Fields wrote:

On Mon, 13 Feb 2006 16:49:58 +0100, "Deefoo"
nonono@wonttell.com
wrote:


"John Fields"
jfields@austininstruments.com> wrote
in message
news:6p71v1lj20hj90topjva2vn7i3k4j8q29a@4ax.com...
On 12 Feb 2006 19:42:27 -0800, "locator299"
locator299@verizon.net
wrote:


I was trying to find a circuit that would give me:
1. A smooth 16 LED sequence blink rate,
2. For one 16 LED one-way sequence,
3. And then STOP after the 16th LED was done.

---
Do you want the 16th LED to stay on at the end of the
sequence
or to
go off?

--
John Fields
Professional Circuit Designer

The OP said "STOP after the 16th LED was done" so
I
suppose this means off.

---
Yes, but rather than suppose, I'd like to know for sure.


Thank you for your help. Yes, I wanted to press a button to start
the
sequence, have LEDs 1 thru 16 light up (in sequence) and then STOP
the
sequence automatically after the 16th LED has lit up.

---
That was over three years ago!

Do you still want a circuit?

JF
Click to expand...

No, after reading Deefoo's comments, I was able to finish the circuit. I
used Deefoo's suggestions to stop the sequence early and to reset the
circuit. Thank you, Deefoo! I'm sorry that it took me so long to get
back. Fate had me pretty busy on other projects for a while, but now I'm
back to pick up where I left off. Again, thank you for your help!

locator299


--
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| no-spam Web and RSS interface to your favorite newsgroup |
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