Timer circuit help

R

Robo

Guest
Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
 
On 19 Nov 2004 18:02:59 -0800, sprintracer@gmail.com (Robo) wrote:

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Click to expand...
Off the top of my head... You could use a 555 for part of the circuit,
running off of the +12 as an astable at 6 Hz. Next to that, use a
voltage divider to 5 V and a cap with a time constant of half a second
or so. Take the output pulse train from the 555 (through another voltage
divider down to 5 V) and the top of the capacitor each to the inputs of
an OR gate.

You'll probably want a diode in parallel with the top of the voltage
divider that drives the cap, so that it dumps quickly when the driving
pulse goes away. Schmitt-trigger inputs on the OR gate.

I'm sure there's a simpler way, but it's getting late...

--
Rich Webb Norfolk, VA
 
Subject: Timer circuit help
From: sprintracer@gmail.com (Robo)
Date: 20/11/2004 02:02 GMT Standard Time
Message-id: <f9de0718.0411191802.2eab29c3@posting.google.com

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Click to expand...
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.
 
"Robo" <sprintracer@gmail.com> schreef in bericht
news:f9de0718.0411191802.2eab29c3@posting.google.com...
Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Click to expand...

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. You can replace this
six ICs by one programmable device, a GAL16V8 for instance, but you have to
add a 5V regulator and some level shifters. The best you can do is using a
little micro like an eight pins Microchip or a tiny AVR. You wil also have
to add 5V regulating and level shifting but it is the smallest solution I
can imagine. (Microchip introduced six pins micros lately but only in SMD
packages.)

petrus bitbyter


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.796 / Virus Database: 540 - Release Date: 13-11-2004
 
Robo wrote:
Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Click to expand...
View in a fixed-width font such as Courier.


+-------------------------------> OUT
|
|
12V>----------+-------------+-------------+--------+
| | | | |
| | \ | |
| | 2R/10 | |
| | \ | |
| | / | |
| | | +-----------------------+
| | | | | | |
| | | | | | |
+----------+ | | | | +----------+ |
| VDD | | | | | | VDD | |
| | | | | | | | |
| | | | | | | | |
IN>--+--|RST OUT|----+------|>|-----+ +--|RST OUT| |
| | | | | | | | | |
| | LMC555 | \ +---+ | \ | LMC555 | |
| | | R | | | 1.5R | | |
| | | \ - | | \ | DIS|---+
| | | / v | | / | |
| | | | - | | | | |
| | THR|----+---+-------+ +-----|THR |
| | | | | | | |
| | TRG|----+ +----------+-----|TRG |
| | | | | | | | |
| | | | | | | | |
| | GND | === | \ === | GND |
| +----------+ |C | R/10 |C +----------+
| | | | \ | |
+-|<|----|---------|---+ / | |
| | | | |
GND>----------+---------+-------+------+-----------+




1.4 x RC= 1/6 => R=120K C=1uF

Then R/10=12K and 2R/10=24K and 1.5R=180K

All diodes 1N914A
 
Ken Moffett wrote:
Robo wrote:

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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

Any help/direction would be greatly appreciated. Thanks...


This looks exactly like a third brake light pulser I built a while back.
Used a 4094 Quad Schmidt NAND. 2 Trim pots to control pulse rate and
window of the pulses. Pulses when you step on the brake, and then stays
on solid until you let up. If you like I'll email you the schematic and
details.

For anyone one that wishes to jump on the legal, moral, and
proctological issues of pulsed brake lights...been there, done that, and
flamed by an automotive lighting engineer (he claimed).
Click to expand...
Okay, so this is a two wire ckt, then you can still do this:
View in a fixed-width font such as Courier.

..
..
.. +--------+-------------+-------------+--------+
.. | | | | |
.. | | | | |
.. | | +-------------------------------> OUT
.. | | | | | |
.. | | | | | |
.. | | | | +-----------------------+
.. | | | | | | | |
.. | | | \ | | | |
.. | +----------+ | 2R/10 | | +----------+ |
.. | | VDD | | \ | | | VDD | |
.. | | | | / | | | | |
.. | | | | | | | | | |
.. IN>--+--|RST OUT|----+------|>|-----+ +--|RST OUT| |
.. | | | | | | | | | |
.. | | LMC555 | \ +---+ | \ | LMC555 | |
.. | | | R | | | 1.5R | | |
.. | | | \ - | | \ | DIS|---+
.. | | | / v | | / | |
.. | | | | - | | | | |
.. | | THR|----+---+-------+ +-----|THR |
.. | | | | | | | |
.. | | TRG|----+ +----------+-----|TRG |
.. | | | | | | | | |
.. | | | | | | | | |
.. | | GND | === | \ === | GND |
.. | +----------+ |C | R/10 |C +----------+
.. | | | | \ | |
.. +-|<|----|---------|---+ / | |
.. | | | | |
.. GND>----------+---------+-------+------+-----------+
..
..
..
..
.. 1.4 x RC= 1/6 => R=120K C=1uF
..
.. Then R/10=12K and 2R/10=24K and 1.5R=180K
..
.. All diodes 1N914A
..
..
 
Fred Bloggs wrote:
Ken Moffett wrote:

Robo wrote:

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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

Any help/direction would be greatly appreciated. Thanks...



This looks exactly like a third brake light pulser I built a while
back. Used a 4094 Quad Schmidt NAND. 2 Trim pots to control pulse
rate and window of the pulses. Pulses when you step on the brake, and
then stays on solid until you let up. If you like I'll email you the
schematic and details.

For anyone one that wishes to jump on the legal, moral, and
proctological issues of pulsed brake lights...been there, done that,
and flamed by an automotive lighting engineer (he claimed).


Okay, so this is a two wire ckt, then you can still do this:
View in a fixed-width font such as Courier.

.
.
. +--------+-------------+-------------+--------+
. | | | | |
. | | | | |
. | | +-------------------------------> OUT
. | | | | | |
. | | | | | |
. | | | | +-----------------------+
. | | | | | | | |
. | | | \ | | | |
. | +----------+ | 2R/10 | | +----------+ |
. | | VDD | | \ | | | VDD | |
. | | | | / | | | | |
. | | | | | | | | | |
. IN>--+--|RST OUT|----+------|>|-----+ +--|RST OUT| |
. | | | | | | | | | |
. | | LMC555 | \ +---+ | \ | LMC555 | |
. | | | R | | | 1.5R | | |
. | | | \ - | | \ | DIS|---+
. | | | / v | | / | |
. | | | | - | | | | |
. | | THR|----+---+-------+ +-----|THR |
. | | | | | | | |
. | | TRG|----+ +----------+-----|TRG |
. | | | | | | | | |
. | | | | | | | | |
. | | GND | === | \ === | GND |
. | +----------+ |C | R/10 |C +----------+
. | | | | \ | |
. +-|<|----|---------|---+ / | |
. | | | | |
. GND>----------+---------+-------+------+-----------+
.
.
.
.
. 1.4 x RC= 1/6 => R=120K C=1uF
.
. Then R/10=12K and 2R/10=24K and 1.5R=180K
.
. All diodes 1N914A
.
.
Click to expand...
well- not quite:
View in a fixed-width font such as Courier.

..
..
.. +--------+-------------+-------------+--------+
.. | | | | |
.. | | | | |
.. | | +-------------------------------> OUT
.. | | | | | |
.. | | | | | |
.. | | | | +-----------------------+
.. | | | | | | | |
.. | | | \ | | | |
.. | +----------+ | 2R/10 | | +----------+ |
.. | | VDD | | \ | | | VDD | |
.. | | | | / | | | | |
.. | | | | | | | | | |
.. IN>--+--|RST OUT|----+------|>|-----+ +--|RST OUT| |
.. | | | | | | | | | |
.. | | LMC555 | \ +---+ | \ | LMC555 | |
.. | | | R | | | 1.5R | | |
.. | | | \ - | | \ | DIS|---+
.. | | | / v | | / | |
.. | | | | - | | | | |
.. | | THR|----+---+-------+ +-----|THR |
.. +--+ | | | | | | |
.. | | | TRG|----+ +----------+-----|TRG |
.. \ | | | | | | | | |
.. R/10 | | | | | | | | |
.. \ | | GND | === | \ === | GND |
.. / | +----------+ |C | R/10 |C +----------+
.. | | | | | \ | |
.. | +-|<|----|---------|---+ / | |
.. | | | | | |
.. GND>-+-----------+---------+-------+------+-----------+
..
..
..
..
.. 1.4 x RC= 1/6 => R=120K C=1uF
..
.. Then R/10=12K and 2R/10=24K and 1.5R=180K
..
.. All diodes 1N914A
..
..
 
sprintracer@gmail.com (Robo) wrote:

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Click to expand...

Here's a circuit to do what you specify:
http://www.terrypin.dial.pipex.com/Images/SpecialAstable-Robo.gif

It requires three cheap and cheerful CMOS 4011 Quad NANDs, with 2
gates left unused.

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
"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.
Click to expand...
Seven chips? Far too complex, as you see from my 3-chip solution just
posted!

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
Jim Thompson <thegreatone@example.com> wrote:

On Sat, 20 Nov 2004 16:19:45 +0000, 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!

Except your "solution" delivers slivers ;-)

...Jim Thompson
Click to expand...
From the OP's spec ("3 to 4 times..."), I understood that an
incomplete pulse was OK, providing there were at least 3 full ones.

Where's your solution?

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
Terry Pinnell 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!

--
Terry Pinnell
Hobbyist, West Sussex, UK
Click to expand...
Seven chipps?....three chips?.... I did it with one 4093 Quad Schmidt
NAND. I'll post it on alt.binaries.schematics.electronic
 
Ken Moffett <KLMoffett@mn.rr.com> wrote:

Terry Pinnell 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!

--
Terry Pinnell
Hobbyist, West Sussex, UK

Seven chipps?....three chips?.... I did it with one 4093 Quad Schmidt
NAND. I'll post it on alt.binaries.schematics.electronic
Click to expand...
Looks good!

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
"Terry Pinnell" <terrypinDELETE@THESEdial.pipex.com> schreef in bericht
news:chrup092f42t64lu9bspp50g1nuq0oc6nt@4ax.com...
"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!

--
Terry Pinnell
Hobbyist, West Sussex, UK
Click to expand...
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.

petrus bitbyter




---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.796 / Virus Database: 540 - Release Date: 14-11-2004
 
"Robo" <sprintracer@gmail.com> wrote

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

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

^ 3-4 pulses 50% duty cycle ~6 Hz
Any help/direction would be greatly appreciated. Thanks...
Click to expand...
Microcontroller: PIC, ARM, whatever you have in the junk drawer
and can still find the programmer for ...

Heck, a used ~200 MHz Pentium, sells for less than a PIC.

--
Nicholas O. Lindan, Cleveland, Ohio
Consulting Engineer: Electronics; Informatics; Photonics.
Remove spaces etc. to reply: n o lindan at net com dot com
psst.. want to buy an f-stop timer? nolindan.com/da/fstop/
 
On 19 Nov 2004 18:02:59 -0800, sprintracer@gmail.com (Robo) wrote:

Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

^ 3-4 pulses 50% duty cycle ~6 Hz
Click to expand...
---
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 Fields
 
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!
Click to expand...
You only need 2 chips. A CD4060 and a quad NOR gate.

--
--
kensmith@rahul.net forging knowledge
 
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.
Click to expand...
---
Why not post a schematic and let us see what you've got?

--
John Fields
 
sprintracer@gmail.com (Robo) wrote in message news:<f9de0718.0411191802.2eab29c3@posting.google.com>...
Looking for a circuit that when the input goes high (+12) the output
will pulse 3 to 4 times with a 50% duty cycle at approx. 6 Hz, and
then remain high as long as the input stays high.
Is it possible to do this with a 555 timer? If so looking for some
help with the circuit, or some other possible simple circuit solution.

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

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

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


Any help/direction would be greatly appreciated. Thanks...
Try this
Click to expand...
http://homepages.slingshot.co.nz/~peg/SED.GIF
 
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
Click to expand...
Like this:


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

--
Terry Pinnell
Hobbyist, West Sussex, UK
 
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