Turning a light on and off with momentary switch

[Robert Monsen]

For another possibility, try this link:

http://home.comcast.net/~rcmonsen/flipper.GIF

I built a circuit nearly identical to this one, which I control with a
small 40MHz radio control. The main problem I have is that the radio
control (which I swiped from a toy car) gets occasional hits, which
trigger the device without warning. I have it hooked up to a large,
lighted, mechanical pink flamingo that my wife decided she needed (and
which was on sale for 1/2 price!). Thus, it goes on occasionally by
itself, which is actually kinda fun.

The circuit itself is really just an inverter flipflop, like this:

R1
___
.---------------|___|---------------------------.
| |
| U1A U1B |
| R1 |
| |\ ___ |\ |
'--------| >O---|___|----------o----| >O----o---'
|/ | |/ |
\ o |
S1 \ |
\. |
o |
| R2 |
| ___ |
o----|___|---'
|
--- C1
---
|
GND

(created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de)

except the inverters are NPN common emitter amplifiers instead of
inverters. IF you close the switch for a moment, the inverter U1B
changes state, thus changing the state of the other inverter. If R2 >>
R1, then even when the button is pressed, it won't oscillate. The cap C1
must be large enough to allow the input of U1B to reach it's switching
threshold for long enough to switch, despite the action of R1.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Peter Michelson]

Thanks for the list of resources, annotations, and candor regarding your
bias
Peter

"Robert Monsen" <rcsurname@comcast.net> wrote in message
news:QeSdnXoSApM8KIrfRVn-gQ@comcast.com...

Peter Michelson wrote:
Would you (or any other reader without commercial bias) please recommend
an
inexpensive and reliable vendor for electronics parts for projects such
as
this one? If such recommendations are not allowed on the newsgroup,
please
feel free to email them to me.


Here are my links to electronics distributors (US bias)

http://www.acroname.com/
http://www.allcorp.com/
http://www.alliedelec.com/
http://www.aade.com/index.html
http://www.sciplus.com/?emailid=25
http://www.bgmicro.com/
http://store.yahoo.com/webtronics/index.html
http://www.componentkits.com/
http://www.elexp.com/
http://www.findchips.com/
http://www.futurlec.com/
http://www.jameco.com/
http://www.thelaserguy.com/index.html
http://www.mcminone.com/
http://www.meci.com/
http://www.mouser.com/
http://www.moyerelectronics.com/
http://www.mpja.com/
http://www.probemaster.com/
http://www.quickar.com/about.htm
http://www.quickar.com/index.php?session=
http://www.goldmine-elec.com/
http://www.commlinx.com.au/timing.htm
http://www.electronicsurplus.com/
http://alltronics.com/wire_and_cable.htm
http://home.att.net/~wzmicro/index.htm
http://www.alltronics.com/
http://www.lsdiodes.com/5mm/
http://www.hosfelt.com/

I usually use goldmine or futurlec for hobby parts. They don't mind
small orders, and don't charge me sales tax (I'm in california)

You can also get samples of parts from distributors like microchip,
analog, linear, national, fairchild, etc.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Peter Michelson]

That looks like a handy circuit that could be adapted to my application. I
might fiddle around with it and compare to the others. Thanks.

Do they sell any kits for this that include the mechanical pink flamingo?


Peter

"Robert Monsen" <rcsurname@comcast.net> wrote in message
news:3dmdnVOV6uGPJorfRVn-hg@comcast.com...

For another possibility, try this link:

http://home.comcast.net/~rcmonsen/flipper.GIF

I built a circuit nearly identical to this one, which I control with a
small 40MHz radio control. The main problem I have is that the radio
control (which I swiped from a toy car) gets occasional hits, which
trigger the device without warning. I have it hooked up to a large,
lighted, mechanical pink flamingo that my wife decided she needed (and
which was on sale for 1/2 price!). Thus, it goes on occasionally by
itself, which is actually kinda fun.

The circuit itself is really just an inverter flipflop, like this:

R1
___
.---------------|___|---------------------------.
| |
| U1A U1B |
| R1 |
| |\ ___ |\ |
'--------| >O---|___|----------o----| >O----o---'
|/ | |/ |
\ o |
S1 \ |
\. |
o |
| R2 |
| ___ |
o----|___|---'
|
--- C1
---
|
GND

(created by AACircuit v1.28 beta 10/06/04 www.tech-chat.de)

except the inverters are NPN common emitter amplifiers instead of
inverters. IF you close the switch for a moment, the inverter U1B
changes state, thus changing the state of the other inverter. If R2
R1, then even when the button is pressed, it won't oscillate. The cap C1
must be large enough to allow the input of U1B to reach it's switching
threshold for long enough to switch, despite the action of R1.

--
Regards,
Robert Monsen

"Your Highness, I have no need of this hypothesis."
- Pierre Laplace (1749-1827), to Napoleon,
on why his works on celestial mechanics make no mention of God.

 

[Peter Michelson]

"Bill Bowden" <wrongaddress@att.net> wrote in message
news:1108675515.525832.218090@g14g2000cwa.googlegroups.com...

Peter Michelson wrote:

As I said, I would like to cycle among three LEDs.
To elaborate: one LED is turned on at any given time;
each time I depress the momentary switch, I would like
the LED that is on to turn off, and the next LED
in sequence to turn on;

There is a "10 stage LED sequencer" at the below address.
You will need to change the 555 oscillator into a
555 "one shot" circuit so you can use a pushbutton.
The 4017 can be used for just 3 LEDs by connecting the
reset line (pin 15) to the 4th output, (pin 7).

http://ourworld.compuserve.com/homepages/Bill_Bowden/page5.htm#4017-2.gif

-Bill

First question: can I use more than one stage of the LED sequencer to
prolong the duration of an LED being on? For example, if I want the first
LED to stay on twice as long as the 2nd and 3rd LEDs, is it sufficient to
connect the first two outputs to the first LED, and then only one output to
each of the other two? In other words, is it a problem to connect two
outputs together without using diodes?

Second question: I have decided to use the approach you recommended (using
the 4017 with transistors to boost the outputs, as depicted in the link
above). In order to drive the process, I would like to use a combination of
the simple toggle provided here:
http://www.terrypin.dial.pipex.com/Images/Toggles-Momentary.gif
and the 555 for automatic operation. In other words, I would like to be
able to switch back and forth between using a momentary switch to control
the LEDs and using the 555 to automatically cycle through them.
Could someone please explain the circuit design necessary for switching
back and forth between the two?

Third question: Alternatively, since the 555 can be used as a debouncer by
itself, is it possible to configure the circuit so the 555 could actually be
used both as a debouncer for manual operation and as a timer (which would
obviate the need for the simple toggle above)?

Fourth question (I think I've well exceeded my quota here): is there any
good freeware or open source software for designing circuits and printing
out those designs?

Thanks a bunch,
Peter

 

[Peter Michelson]

<wrongaddress@att.net> wrote in message
news:1109305653.532488.48200@o13g2000cwo.googlegroups.com...

Peter Michelson wrote:

First question: can I use more than one stage of the
LED sequencer to prolong the duration of an LED being on?
For example, if I want the first LED to stay on twice as
long as the 2nd and 3rd LEDs, is it sufficient to connect
the first two outputs to the first LED, and then only one
output to each of the other two? In other words, is it a
problem to connect two outputs together without using diodes?


Yes, it is a problem, you need diodes. See my traffic light
circuit for an example:


http://ourworld.compuserve.com/homepages/Bill_Bowden/page10.htm#traffic.gif

-Bill

Perfect - thank you. Also, that seems like an elegant/parsimonious circuit
design.

Incidentally, what software do you use for rendering your circuits designs
as they appear on the links you have provided?

Thanks again,
Peter

 

[Peter Michelson]

<wrongaddress@att.net> wrote in message
news:1109482647.784238.12890@z14g2000cwz.googlegroups.com...

Incidentally, what software do you use for rendering your
circuits designs as they appear on the links you have
provided?

The software is an old DOS program called "Colorix VGA Paint" 1989.

It's similar to Windows "Paint" with more features.
It's easy to copy and paste, and move things around.
Windows "Paint" can do the same thing, but has limited
editing features.

-Bill

Impressive. Because of the high quality, I didn't realize that you drew

them manually. I thought they were created by an electronics CAD program.

Does Colorix VGA Paint run in a DOS window on a pentium class machine?

Regards,
Peter

 

Does Colorix VGA Paint run in a DOS window on
a pentium class machine?

Yes, it runs in a DOS window on Win 95,98,2000 and
Xp. But I forgot to mention the Colorix program produces .GIF files
directly while Windows Paint only produces .BMP files which need
conversion. There are utilities to convert formats, but it's nice to
get the finished drawing in the right format without conversion
problems.

The first few drawings took some time, but as the library grew, I can
usually find a drawing close to what I need, start with that, and just
move things around to create a new drawing.

-Bill

 

[Michael A. Terrell]

Robert Monsen wrote:

FYI, Paint under XP can save files as GIF, TIFF, JPG, and PNG, as well
as various levels of bitmap. You need to change the popup menu on the
saveas dialog to indicate the proper format.

--
Regards,
Robert Monsen

It works the same for ME as well.

--
Beware of those who post from srvinet.com!

Michael A. Terrell
Central Florida