Timer circuit help

[John Fields]

On Sun, 21 Nov 2004 11:51:21 GMT, Rich Grise <rich@example.net> wrote:

On Sun, 21 Nov 2004 08:41:50 +0000, Terry Pinnell wrote:

"petrus bitbyter" <p.kralt@reducespamforchello.nl> wrote:

Well,

If it fulfils the OPs requirements the better but it does not give three or
four pulses with a 50% dutycycle he asked for. You will get some pulses of
unspecified length and a lot of digital appliances will react with
unexpected actions. The solutions I have in mind produce three (or four) 6Hz
pulses with a dutycycle of 50%, no more, no less. Which requires some more -
and a little bit more complicated - electronics then the solution you
suggested.

You may be right, but I think it largely depends on exactly what the
OP meant by "...the output will pulse 3 to 4 times with a 50% duty
cycle..." I noted that he didn't say "3 *or* 4...". So I've assumed
that, if there were 4 pulses, the 4th was allowed to be of unspecified
length. In fact, I'm not sure how else you could interpret that
wording?

So, Robo, let's hear from you! BTW, if you actually *meant* "3 or
4...", does that mean a switchable option? Or you haven't made your
mind up yet?

He probably simply means "a few", and has left it to the discretion
of the designer, as to exactly how many pulses pulse. I think it's
already been established that the OP was looking for a brake light
flasher,

---
That the OP was looking for a brake light flasher is, I believe,
conjecture and hasn't been confirmed by the OP, so I think
"established" is premature.
---

and there's already been a thread spun off as to the legalities
of something like that.

So design something that does three, design something that does four,
and compare them, and do the easier one. ;-)

Have Fun!
Rich

--
John Fields

 

[Robo]

John Fields <jfields@austininstruments.com> wrote in message news:<q8nvp019gp5lr2rib2a0qvthr6q908mr6n@4ax.com>...

---
2 chip, 3 pulse solution on abse under "Timer circuit help"

Not exactly 50% duty cycle, but I can get it there with one more chip
or maybe a different shift register and reworking the logic a little.

How close to 50% do you need?

John,

The 50% duty cycle is not critical.

Thanks for the help, much appreciated.

Rob...

 

[Robo]

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.

You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

Thanks everyone for all the help.

Robo....

 

[Rich Webb]

On 21 Nov 2004 08:08:20 -0800, sprintracer@gmail.com (Robo) wrote:

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.


You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

www.avrfreaks.net is an excellent resource for the Atmel AVR chips. They
have info on roll-yer-own programmers and also links to a GPL C suite.

FWIW, Atmel does have a very inexpensive in-system programmer for only
about $30 (digikey and many others). I'm also fond of the ImageCraft
compiler tools. www.imagecraft.com/software

--
Rich Webb Norfolk, VA

 

[Terry Pinnell]

sprintracer@gmail.com (Robo) wrote:

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.


You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

How about answering a few of the questions outstanding, before moving
onto your next batch of queries?

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Ken Moffett]

Robo wrote:

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.

You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

Thanks everyone for all the help.

Robo....

I've recently started using PicAxe's. They come in 8-pin to 40-pin
versions, have an onboard Basic interpreter, free programming software,
and are a whole lot cheaper (even at USD-Euro exchange rates) than Basic
Stamps. They may not be as fast as straight PICs, but they is a nice
cheap, easy to code micro. I'd use the Picaxe08 now, instead of the 4093
(discrete?) in my flasher circuit.

 

[Ken Moffett]

Robo wrote:

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.

You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

Thanks everyone for all the help.

Robo....

Sorry, I forgot to include the URL for PicAxe:
http://www.rev-ed.co.uk/picaxe/

 

[John Fields]

On Sun, 21 Nov 2004 17:12:09 +0000 (UTC), kensmith@green.rahul.net
(Ken Smith) wrote:

In article <bo91q09lh5av2buu86oh6ca7oj09rcpnc2@4ax.com>,
John Fields <jfields@austininstruments.com> wrote:
On Sun, 21 Nov 2004 01:49:02 +0000 (UTC), kensmith@green.rahul.net
(Ken Smith) wrote:

In article <5tqvp0hdt2ppkh3infht66i7pe2mlhk64l@4ax.com>,
John Fields <jfields@austininstruments.com> wrote:
[...]
-----!\
----+ ! O--+------------------------!\
-----!/ ! ! O----- Out
! Qn -----!/
!
! --------------------
-----!R 4060 !
! !
----!--!>o- !
! ! ! !
! --------------------
! !
! ---
! ---
! !
+---/\/\/\--+
! !
! \
! /
! \
! !
! /!-----
----O !
\!--------Q(n+2)

---
Neat, _and_ 50% duty cycle, but since the earliest output from the
4060 is Q3, there will be 8 clock cycles between IN going high and OUT
going active, which isn't what the OP's timing diagram:


No, the circuit works fine. Those are all NOR gates.

When the reset first goes away, Qn is low. The output goes high right
away.

After some clock cycles, Qn goes high causing the low on the output.

After that same number of pulses, Qn goes low.

---
Yes, I see it now. Very nice!

Thanks,

--
John Fields

 

[petrus bitbyter]

"Ken Smith" <kensmith@green.rahul.net> schreef in bericht
news:cnos6e$u0d$2@blue.rahul.net...

In article <5tqvp0hdt2ppkh3infht66i7pe2mlhk64l@4ax.com>,
John Fields <jfields@austininstruments.com> wrote:
On Sun, 21 Nov 2004 01:01:21 +0000 (UTC), kensmith@green.rahul.net
(Ken Smith) wrote:

In article <chrup092f42t64lu9bspp50g1nuq0oc6nt@4ax.com>,
Terry Pinnell <terrypinDELETE@THESEdial.pipex.com> wrote:
"petrus bitbyter" <p.kralt@reducespamforchello.nl> wrote:


A 555 is a timer and it can only be used for timing in this problem
i.e.
producing a 12Hz clock. Except for the 555 you will need about six
other 12V
(CMOS) packages to complete a full functioning circuit.

Seven chips? Far too complex, as you see from my 3-chip solution just
posted!

You only need 2 chips. A CD4060 and a quad NOR gate.

---
Why not post a schematic and let us see what you've got?

--
John Fields

Like this:


-----!\
----+ ! O--+------------------------!\
-----!/ ! ! O----- Out
! Qn -----!/
!
! --------------------
-----!R 4060 !
! !
----!--!>o- !
! ! ! !
! --------------------
! !
! ---
! ---
! !
+---/\/\/\--+
! !
! \
! /
! \
! !
! /!-----
----O !
\!--------Q(n+2)
--
--
kensmith@rahul.net forging knowledge

Looks like a bright idea but... unless I'm much mistaken - I have no
datasheet of the 4060 available at the moment - the circuit will produce
four pulses and then keeps the output low.

petrus bitbyter



---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.799 / Virus Database: 543 - Release Date: 19-11-2004

 

[Ken Smith]

In article <kG6od.5872$_u6.4503@amsnews02.chello.com>,
petrus bitbyter <p.kralt@reducespamforchello.nl> wrote:

"Ken Smith" <kensmith@green.rahul.net> schreef in bericht
[...]

Note the indicated NOR gate ...........

\
-----!\ \
----+ ! O--+------------------------!\
-----!/ ! ! O----- Out
! Qn -----!/
!
! --------------------
-----!R 4060 !
! !
----!--!>o- !
! ! ! !
! --------------------
! !
! ---
! ---
! !
+---/\/\/\--+
! !
! \
! /
! \
! !
! /!-----
----O !
\!--------Q(n+2)
--
--
kensmith@rahul.net forging knowledge



Looks like a bright idea but... unless I'm much mistaken - I have no
datasheet of the 4060 available at the moment - the circuit will produce
four pulses and then keeps the output low.

The 4060 does this:

---- ----
Qn ---- ---- -----------------

--------
Qn+1 -------- -----------------

-----------------
Qn+2 ----------------

The NOR gate in the output turns the 2 pulses on Qn into two downward
pulses.

The NOR gate in the oscillator makes the oscillator stop when Qn+2 goes
high.


--
--
kensmith@rahul.net forging knowledge

 

[Robo]

On Sun, 21 Nov 2004 16:31:51 +0000, Terry Pinnell
<terrypinDELETE@THESEdial.pipex.com> wrote:

sprintracer@gmail.com (Robo) wrote:

cbarn24050@aol.com (CBarn24050) wrote in message news:<20041120040014.08392.00000914@mb-m04.aol.com>...

Easy enough with 555, but you will need 2 of them. The modern way is to use a
micro, as you will need to learn how to use them eventually you might as well
start now.


You guys are right, I need to learn micros (for my next project ).
Any good sites sites with programmer plans and software? Anyone
have preference for either PICs or AVRs?

How about answering a few of the questions outstanding, before moving
onto your next batch of queries?

Terry,

I didn't intentionally not answer questions. My news server is pretty
lame and messages show up sporatically and I had not seen your
questions when I responded before.

There really is nothing critical to this circuit as it will be used to
drive a visual indicator (similar to the pulsing brake light). So
when I said 3 to 4, it was meant as a ballpark figure. With that
said, the slivers are totally acceptable as well.

I don't like to consider myself "politically correct", but everyones
designs would work. Thanks for all the help, you guys are great!

Robo...

 

[Terry Pinnell]

Robo <sprintracer@gmial.com> wrote:

Terry,

I didn't intentionally not answer questions. My news server is pretty
lame and messages show up sporatically and I had not seen your
questions when I responded before.

There really is nothing critical to this circuit as it will be used to
drive a visual indicator (similar to the pulsing brake light). So
when I said 3 to 4, it was meant as a ballpark figure. With that
said, the slivers are totally acceptable as well.

I don't like to consider myself "politically correct", but everyones
designs would work. Thanks for all the help, you guys are great!

Robo...

OK, thanks. Hope you get a practical circuit working. I'd be
interested to get some feedback when you do.

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Rich The Philosophizer]

On Sun, 21 Nov 2004 08:32:28 -0600, John Fields wrote:

On Sun, 21 Nov 2004 11:51:21 GMT, Rich Grise <rich@example.net> wrote:

He probably simply means "a few", and has left it to the discretion
of the designer, as to exactly how many pulses pulse. I think it's
already been established that the OP was looking for a brake light
flasher,

---
That the OP was looking for a brake light flasher is, I believe,
conjecture and hasn't been confirmed by the OP, so I think
"established" is premature.
---

Well, Robo did say "similar to":
-----------------------
Terry,

I didn't intentionally not answer questions. My news server is pretty
lame and messages show up sporatically and I had not seen your
questions when I responded before.

There really is nothing critical to this circuit as it will be used to
drive a visual indicator (similar to the pulsing brake light). So
when I said 3 to 4, it was meant as a ballpark figure. With that
said, the slivers are totally acceptable as well.

I don't like to consider myself "politically correct", but everyones
designs would work. Thanks for all the help, you guys are great!

Robo...
------------------------------
So, I guess you're right, John. It hasn't been "established."

But I think somebody claimed you could do it with two 555's - you can
also get a 556, which has two 555 timer circuits in one package. :=)

Thanks!
Rich

 

[Terry Pinnell]

John Fields <jfields@austininstruments.com> wrote:

2 chip, 3 pulse solution on abse under "Timer circuit help"

Not exactly 50% duty cycle, but I can get it there with one more chip
or maybe a different shift register and reworking the logic a little.

Here's an alternative approach, also using 2 ICs:
http://www.terrypin.dial.pipex.com/Images/SpecialAstable4017-Robo.gif

(Also posted in alt.binaries.schematics.electronic)

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[John Fields]

On Mon, 22 Nov 2004 07:14:38 GMT, Rich The Philosophizer
<null@example.net> wrote:

On Sun, 21 Nov 2004 08:32:28 -0600, John Fields wrote:

On Sun, 21 Nov 2004 11:51:21 GMT, Rich Grise <rich@example.net> wrote:

He probably simply means "a few", and has left it to the discretion
of the designer, as to exactly how many pulses pulse. I think it's
already been established that the OP was looking for a brake light
flasher,

---
That the OP was looking for a brake light flasher is, I believe,
conjecture and hasn't been confirmed by the OP, so I think
"established" is premature.
---

Well, Robo did say "similar to":

---
Yes, and Jupiter is similar to Earth because they're both planets.
---

-----------------------
Terry,

I didn't intentionally not answer questions. My news server is pretty
lame and messages show up sporatically and I had not seen your
questions when I responded before.

There really is nothing critical to this circuit as it will be used to
drive a visual indicator (similar to the pulsing brake light). So
when I said 3 to 4, it was meant as a ballpark figure. With that
said, the slivers are totally acceptable as well.

I don't like to consider myself "politically correct", but everyones
designs would work. Thanks for all the help, you guys are great!

Robo...
------------------------------
So, I guess you're right, John. It hasn't been "established."

---
Yes, I am, because it's not "hasn't" ya goddam cheater, it's "hadn't".
---

But I think somebody claimed you could do it with two 555's - you can
also get a 556, which has two 555 timer circuits in one package. :=)

---
Old news.

--
John Fields

 

[John Fields]

On Mon, 22 Nov 2004 07:16:51 GMT, Rich The Philosophizer
<null@example.net> wrote:

Even I'll chime in here

---
"Even" you?

Don't be absurd. Self-restraint in the face of ignorance has never
been one of your "shortcomings", Rich.

I'f you'd have even bothered to read the thread you might have run
across this little gem:



"You only need 2 chips. A CD4060 and a quad NOR gate.

--
--
kensmith@rahul.net forging knowledge"

--
John Fields

 

[Ken Smith]

In article <6454q0ploo2rsidfo864jrl5fq6v15tckd@4ax.com>,
John Fields <jfields@austininstruments.com> wrote:

On Mon, 22 Nov 2004 07:16:51 GMT, Rich The Philosophizer
null@example.net> wrote:


Even I'll chime in here

---
"Even" you?

Don't be absurd. Self-restraint in the face of ignorance has never
been one of your "shortcomings", Rich.

I'f you'd have even bothered to read the thread you might have run
across this little gem:



"You only need 2 chips. A CD4060 and a quad NOR gate.

I'll say it before anyone else thinks to:
Which as it turns out is a lie. You need 1 CD4060 and 0.75 quad NOR gate.
--
--
kensmith@rahul.net forging knowledge

 

[Terry Pinnell]

kensmith@green.rahul.net (Ken Smith) wrote:

Neat, _and_ 50% duty cycle, but since the earliest output from the
4060 is Q3, there will be 8 clock cycles between IN going high and OUT
going active, which isn't what the OP's timing diagram:


No, the circuit works fine. Those are all NOR gates.

When the reset first goes away, Qn is low. The output goes high right
away.

After some clock cycles, Qn goes high causing the low on the output.

After that same number of pulses, Qn goes low.




Input:
____________________________
_____| |___........

Output:
_ _ ____________________
_____| |_| |_| |___........

^ 3-4 pulses 50% duty cycle ~6 Hz

I'd hoped to breadboard your neat solution but found I had no 4060s.
And when I turned to CircuitMaker to try a simulation instead, I was
disappointed to find its model library has no 4060.

However, it does have the 4020, which is essentially an almost
identical 14-stage ripple counter, although lacking the oscillator
section of the 4060. But so far my attempts to implement your approach
with a 4020 (and a few NORs, which I assume are 4001s?) has failed.
Anyone else able to do that please?

--
Terry Pinnell
Hobbyist, West Sussex, UK

 

[Fred Bloggs]

John Fields wrote:

On Mon, 22 Nov 2004 07:16:51 GMT, Rich The Philosophizer
null@example.net> wrote:



Even I'll chime in here


---
"Even" you?

Don't be absurd. Self-restraint in the face of ignorance has never
been one of your "shortcomings", Rich.

I'f you'd have even bothered to read the thread you might have run
across this little gem:



"You only need 2 chips. A CD4060 and a quad NOR gate.

The simplest circuit possible for a hobbyist is the dual 555 circuit:
the first 555 is a standard 6Hz astable and its output is used to
produce a modified staircase ( okay - a rampcase) charge-up of voltage
into the threshold input of second 555 configured as a comparator- the
second 555 latches the whole thing up when threshold is crossed- and a
simple RC is used to program the number of astable pulses required to
cross that threshold. Everything is ratiometric, no pots required,
everything works right out of the box- which is more than can be said
for these Schmitt trigger based digital astables.

 

[Fred Bloggs]

Fred Bloggs wrote:

Terry Pinnell wrote:

kensmith@green.rahul.net (Ken Smith) wrote:


Neat, _and_ 50% duty cycle, but since the earliest output from the
4060 is Q3, there will be 8 clock cycles between IN going high and OUT
going active, which isn't what the OP's timing diagram:



No, the circuit works fine. Those are all NOR gates.

When the reset first goes away, Qn is low. The output goes high
right away.
After some clock cycles, Qn goes high causing the low on the output.
After that same number of pulses, Qn goes low.





Input:
____________________________
_____| |___........

Output:
_ _ ____________________
_____| |_| |_| |___........

^ 3-4 pulses 50% duty cycle ~6 Hz



I'd hoped to breadboard your neat solution but found I had no 4060s.
And when I turned to CircuitMaker to try a simulation instead, I was
disappointed to find its model library has no 4060.

However, it does have the 4020, which is essentially an almost
identical 14-stage ripple counter, although lacking the oscillator
section of the 4060. But so far my attempts to implement your approach
with a 4020 (and a few NORs, which I assume are 4001s?) has failed.
Anyone else able to do that please?


You don't need any NOR gates whatsoever- you take Qn+3 and stuff a one
on that RTC input of the oscillator , pin 10, through a diode and the
4060 freezes in Qn=0 state which is the turn-on polarity for the bulb.
The n runs 1-14 and then RT x CT= 1/(2.3*6Hz*2^n) by the data sheet.

Maybe stressful on the chip- stuff that diode series '1' onto RS pin 11.