I want a circuit that will turn a light on with the press of a momentary
switch and then turn it back off when the momentary switch is hit
again. I had heard that a flip flop might be the way to go. After some
reading, I have found that a flip flop is a much more complex device
than I was lead to believe. I think a flip flop would some how do the
job, but it is going to take some more reading before I figure out how.
If you have been reading some of my other posts, you know that I want to
turn on and off more than one light, so I need several of these
circuits, preferably using the minimum number of components.

Another option I would like to explore is to turn the light on and off
using 2 inputs. Say we have in put A and B. If input B is high, when
input A goes high, turn the light on, or leave it on. If input B is
low, when input A goes hight, turn the light off, or leave it off.

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

Chris W wrote:
I want a circuit that will turn a light on with the press of a
momentary
switch and then turn it back off when the momentary switch is hit
again. I had heard that a flip flop might be the way to go. After
some
reading, I have found that a flip flop is a much more complex device
than I was lead to believe. I think a flip flop would some how do
the
job, but it is going to take some more reading before I figure out
how.
If you have been reading some of my other posts, you know that I want
to
turn on and off more than one light, so I need several of these
circuits, preferably using the minimum number of components.

Another option I would like to explore is to turn the light on and
off
using 2 inputs. Say we have in put A and B. If input B is high,
when
input A goes high, turn the light on, or leave it on. If input B is
low, when input A goes hight, turn the light off, or leave it off.

--
Chris W

Yes, a flip-flop would do it and someone is sure to suggest a PIC, both
requiring a fair amount of extra components to actually work. Have you
looked for alternate action switches or relays? It would run your
lights and not require a degree to get it to work.
Glenn Gundlach

Yes, a flip-flop would do it and someone is sure to suggest a PIC, both
requiring a fair amount of extra components to actually work. Have you
looked for alternate action switches or relays? It would run your
lights and not require a degree to get it to work.
Glenn Gundlach


Is that because flip-flops require capacitors to store state information? I
would be interested to know the minimum complement of components necessary
to support a single flip-flop. Perhaps there is a good link to this kind of
information (?)

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for this
using flip-flops complex? Is there an easier way to generate the same
functionality? It seems that there must be some ICs out there that provide
this kind of functionality out of the box. Does anyone know of any?

Thanks a lot!
Peter

On Wed, 16 Feb 2005 18:12:59 -0500, "Peter Michelson"
wrote:

Yes, a flip-flop would do it and someone is sure to suggest a PIC, both
requiring a fair amount of extra components to actually work. Have you
looked for alternate action switches or relays? It would run your
lights and not require a degree to get it to work.
Glenn Gundlach


Is that because flip-flops require capacitors to store state information? I
would be interested to know the minimum complement of components necessary
to support a single flip-flop. Perhaps there is a good link to this kind of
information (?)

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for this
using flip-flops complex? Is there an easier way to generate the same
functionality? It seems that there must be some ICs out there that provide
this kind of functionality out of the box. Does anyone know of any?

Thanks a lot!
Peter

You can use an led chaser kit to do the sequental leds. You can
use just the first two outputs on the chip for flip-flop. I've
got a page below showing some tinkering with the 4017 decade
counter chip that might be useful.

http://www.geocities.com/zoomkat/RSswitcher.htm

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for
this
using flip-flops complex? Is there an easier way to generate the same
functionality? It seems that there must be some ICs out there that
provide
this kind of functionality out of the box. Does anyone know of any?

Thanks a lot!
Peter

You can use an led chaser kit to do the sequental leds. You can
use just the first two outputs on the chip for flip-flop. I've
got a page below showing some tinkering with the 4017 decade
counter chip that might be useful.

http://www.geocities.com/zoomkat/RSswitcher.htm


Thanks for the ideas! Also, interesting link.
Regards,
Peter

On Wed, 16 Feb 2005 18:12:59 -0500, "Peter Michelson"
wrote:

Yes, a flip-flop would do it and someone is sure to suggest a PIC, both
requiring a fair amount of extra components to actually work. Have you
looked for alternate action switches or relays? It would run your
lights and not require a degree to get it to work.
Glenn Gundlach


Is that because flip-flops require capacitors to store state information?

---
No.
---

I would be interested to know the minimum complement of components necessary
to support a single flip-flop.

---
Just one, the driver.
---

information (?)

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for this
using flip-flops complex?

---
If you have to ask... Simple for me might be impossible for you, but
you haven't yet described what it is you expect the momentary switch
to do.
---

Is there an easier way to generate the same functionality?

---
What _functionality_?
---


It seems that there must be some ICs out there that provide
this kind of functionality out of the box. Does anyone know of any?

---
Pretty much any µC...

--
John Fields

Thank you for your reply.

"John Fields" wrote in message
...

I would be interested to know the minimum complement of components
necessary
to support a single flip-flop.

---
Just one, the driver.
---
Is there a more specific term for "driver"? I am not familiar with a
component by that name.

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for
this
using flip-flops complex?

---
If you have to ask... Simple for me might be impossible for you, but

Good point. Simple for me means that few (e.g., less than 5) components are
involved and testing can be done with a multimeter.

you haven't yet described what it is you expect the momentary switch
to do.
---

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; the first LED is considered to follow the third in a cyclical
manner. I imagine that this circuit is functionally similar to one that
would drive marquis lights, except that instead of using a timer chip, it is
user-driven.

Is there an easier way to generate the same functionality?

---
What _functionality_?
---

I hope the more complete description above is easier to understand than the
one in my first posting.


It seems that there must be some ICs out there that provide
this kind of functionality out of the box. Does anyone know of any?

---
Pretty much any µC...

Is there one in particular that is best-suited to the functionality
described above?

--
John Fields

Thanks again for your reply.

On Wed, 16 Feb 2005 19:33:08 -0500, "Peter Michelson"
wrote:

Thank you for your reply.

"John Fields" wrote in message
.. .

I would be interested to know the minimum complement of components
necessary
to support a single flip-flop.

---
Just one, the driver.
---
Is there a more specific term for "driver"? I am not familiar with a
component by that name.

---
The driver would be the device/circuit sending the information to the
flip-flop which would cause it to flip or flop.
---

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for
this
using flip-flops complex?

---
If you have to ask... Simple for me might be impossible for you, but

Good point. Simple for me means that few (e.g., less than 5) components are
involved and testing can be done with a multimeter.

--
OK
--

you haven't yet described what it is you expect the momentary switch
to do.
---

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; the first LED is considered to follow the third in a cyclical
manner. I imagine that this circuit is functionally similar to one that
would drive marquis lights, except that instead of using a timer chip, it is
user-driven.

---
"Marquee" lights?^)
---

Is there an easier way to generate the same functionality?

---
What _functionality_?
---

I hope the more complete description above is easier to understand than the
one in my first posting.

---
Yes, it is.

I'll reply, tomorrow or the day after, with a schematic which will
solve your problem.

Thanks again for your reply.

You're welcome.

--
John Fields

"Peter Michelson" wrote in message
news:bDRQd.9917$Ps.1740@okepread06...
Thank you for your reply.

"John Fields" wrote in message
...

I would be interested to know the minimum complement of components
necessary
to support a single flip-flop.

---
Just one, the driver.
---
Is there a more specific term for "driver"? I am not familiar with a
component by that name.

A flip-flop basically stores a 1 or a 0, ON or OFF, respectively. It can't
switch between the two by itself. It needs additional circuitry to drive it,
or basically tell it when to switch the flip-flop from 0 to 1, and 1 to 0.

I have a similar request as the original poster. I would like to use a
momentary switch to cycle among three LEDs. Is the circuit design for
this
using flip-flops complex?

---
If you have to ask... Simple for me might be impossible for you, but

Good point. Simple for me means that few (e.g., less than 5) components
are
involved and testing can be done with a multimeter.

A component might be an IC, or a PIC which might be pretty advanced for an
electronics hobbyst.

you haven't yet described what it is you expect the momentary switch
to do.
---

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; the first LED is considered to follow the third in a cyclical
manner. I imagine that this circuit is functionally similar to one that
would drive marquis lights, except that instead of using a timer chip, it
is
user-driven.

A PIC would suit perfectly for this type of application but it requires some
funds for a PIC programmer (hardware) and coding the PIC (software). You'd
have to know how to program to use a PIC.

Is there an easier way to generate the same functionality?

---
What _functionality_?
---

I hope the more complete description above is easier to understand than
the
one in my first posting.


It seems that there must be some ICs out there that provide
this kind of functionality out of the box. Does anyone know of any?

---
Pretty much any µC...

Is there one in particular that is best-suited to the functionality
described above?

--
John Fields

Thanks again for your reply.

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/homep...htm#4017-2.gif

-Bill

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/homep...htm#4017-2.gif

-Bill

"Chris W" schreef in bericht
news:2OOQd.63983$jn.59042@lakeread06...
I want a circuit that will turn a light on with the press of a momentary
switch and then turn it back off when the momentary switch is hit again. I
had heard that a flip flop might be the way to go. After some reading, I
have found that a flip flop is a much more complex device than I was lead
to believe. I think a flip flop would some how do the job, but it is going
to take some more reading before I figure out how. If you have been
reading some of my other posts, you know that I want to turn on and off
more than one light, so I need several of these circuits, preferably using
the minimum number of components.
Another option I would like to explore is to turn the light on and off
using 2 inputs. Say we have in put A and B. If input B is high, when
input A goes high, turn the light on, or leave it on. If input B is low,
when input A goes hight, turn the light off, or leave it off.

--
Chris W

Gift Giving Made Easy
Get the gifts you want & give the gifts they want
http://thewishzone.com

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin, 1759
Historical Review of Pennsylvania


Chris,

What kind of lights do you want to switch? It makes a lot of difference
whether you want to switch a LED (~40mW) or a 100W incandescent bulb.

The most simple solution I can imagine is a tablelamp pushbutton switch.
Conrad sells them for ?2,20 but I guess you can do cheaper locally. It does
exactly what you describe. Push on, push off, push on, push off and so on.

A more expensive but still simple solution goes with a relay of the same
voltage as the lamp, a make- and a break pushbutton. Conrad sells relay from
below ?2,-- upward and pushbuttons from below ?1,00 upward depending on
voltages and currents required. Digikey will sell similar components but I
have no catalog at hand.

LEDs can be controlled easily using electronics and that's where the
flip-flop appears. You need a so called T-flipflop but they are not very
common. Use an D-type flipflop instead and connect the inverted Q-output
(/Q) to the D-input. Every pulse on the clock input will make the flipflop
change state. So a pushbutton on that input will theoretically do the job.
But a flipflop is a high speed switching device and will see a lot of pulses
every time you push and you can not predict the last one. So you need to
debounce your pushbutton carefully which requires some extra electronics.

Of course you can use a microcontoller as wel. Microchip sells 6 pins ones
these days and the only extra components you need is the pushbutton, the LED
and maybe two resistors. The problem of course is skills and equipment to
program them.

petrus bitbyter

petrus bitbyter wrote:


Chris,

What kind of lights do you want to switch? It makes a lot of
difference whether you want to switch a LED (~40mW) or a 100W
incandescent bulb.

For the first application I just want to switch 1 or maybe 2 LED's
hooked in parallel. They could be of different colors and therefore
different voltages so I am guessing even for just one led on each line I
probably need some kind of a driver so I can match the voltage and
current for each load. Future applications will need to switch around
10W lights, probably in the form of groups of LEDs, on and off.


LEDs can be controlled easily using electronics and that's where the
flip-flop appears. You need a so called T-flipflop but they are not
very common. Use an D-type flipflop instead and connect the inverted
Q-output (/Q) to the D-input. Every pulse on the clock input will make
the flipflop change state. So a pushbutton on that input will
theoretically do the job. But a flipflop is a high speed switching
device and will see a lot of pulses every time you push and you can
not predict the last one. So you need to debounce your pushbutton
carefully which requires some extra electronics.

After some more reading on flip flops I figured this out on my own. If
you read my post in 2-14-2005, you can read more about my application.
What I would really like to find is an IC with as many as 16 D flip
flops that are already wired up like you described. I don't suppose
finding that is likely?


Of course you can use a microcontoller as wel. Microchip sells 6 pins
ones these days and the only extra components you need is the
pushbutton, the LED and maybe two resistors. The problem of course is
skills and equipment to program them.

I'm thinking about getting one of the RABBIT modules, that way I don't
think I need a separate programmer do I?

--
Chris W

Gift Giving Made Easy
Get the gifts you want &
give the gifts they want
http://thewishzone.com

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

"Chris W" schreef in bericht
news:vJWQd.64020$jn.59932@lakeread06...
petrus bitbyter wrote:


Chris,

What kind of lights do you want to switch? It makes a lot of difference
whether you want to switch a LED (~40mW) or a 100W incandescent bulb.

For the first application I just want to switch 1 or maybe 2 LED's hooked
in parallel. They could be of different colors and therefore different
voltages so I am guessing even for just one led on each line I probably
need some kind of a driver so I can match the voltage and current for each
load. Future applications will need to switch around 10W lights, probably
in the form of groups of LEDs, on and off.


One or two LEDs in series can be driven by some logic devices. For more LEDs
or lamps you will need a transistor driver or a relay.


LEDs can be controlled easily using electronics and that's where the
flip-flop appears. You need a so called T-flipflop but they are not very
common. Use an D-type flipflop instead and connect the inverted Q-output
(/Q) to the D-input. Every pulse on the clock input will make the
flipflop change state. So a pushbutton on that input will theoretically
do the job. But a flipflop is a high speed switching device and will see
a lot of pulses every time you push and you can not predict the last one.
So you need to debounce your pushbutton carefully which requires some
extra electronics.

After some more reading on flip flops I figured this out on my own. If
you read my post in 2-14-2005, you can read more about my application.
What I would really like to find is an IC with as many as 16 D flip flops
that are already wired up like you described. I don't suppose finding
that is likely?


Missed your post of 2-14-2005. Can't even find it in the Google groups.

AFAIK such a device does not exist and its very unlikely you'll ever find
one. You can design one for yourself using PLDs but that requires quite some
skills and programming equipment. Especially if you want to incorporate
debouncing. Even then you wil need power drivers to control loads over some
hundreds of mW.


Of course you can use a microcontoller as wel. Microchip sells 6 pins
ones these days and the only extra components you need is the pushbutton,
the LED and maybe two resistors. The problem of course is skills and
equipment to program them.

I'm thinking about getting one of the RABBIT modules, that way I don't
think I need a separate programmer do I?


FAIK RABBIT devices also requires programming which can be done using C. You
will also need a pretty expensive development system and the modules
themselves does look like to be cheap either.

Did you realise a module like you want, needs at least 34 pins? I think a 40
pins micro comes most close to that. A PIC16F877 is one of the cheaper
$10,-- examples. Software is free from Microchip and programming tools can
be bought or home made. You can find a lot of information on
http://www.voti.nl/swp/n_index.html
but it's for sure not the only one a the on the net.

--
Chris W

Gift Giving Made Easy
Get the gifts you want & give the gifts they want
http://thewishzone.com

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin, 1759
Historical Review of Pennsylvania


petrus bitbyter

Chris W wrote:

I want a circuit that will turn a light on with the press of a momentary
switch and then turn it back off when the momentary switch is hit
again. I had heard that a flip flop might be the way to go. After some
reading, I have found that a flip flop is a much more complex device
than I was lead to believe. I think a flip flop would some how do the
job, but it is going to take some more reading before I figure out how.
If you have been reading some of my other posts, you know that I want to
turn on and off more than one light, so I need several of these
circuits, preferably using the minimum number of components.

Another option I would like to explore is to turn the light on and off
using 2 inputs. Say we have in put A and B. If input B is high, when
input A goes high, turn the light on, or leave it on. If input B is
low, when input A goes hight, turn the light off, or leave it off.

Here are three practical circuits you can experiment with:
http://www.terrypin.dial.pipex.com/I...-Momentary.gif

--
Terry Pinnell
Hobbyist, West Sussex, UK

On Wed, 16 Feb 2005 15:19:19 -0600, Chris W wrote:

I want a circuit that will turn a light on with the press of a momentary
switch and then turn it back off when the momentary switch is hit
again. I had heard that a flip flop might be the way to go. After some
reading, I have found that a flip flop is a much more complex device
than I was lead to believe. I think a flip flop would some how do the
job, but it is going to take some more reading before I figure out how.
If you have been reading some of my other posts, you know that I want to
turn on and off more than one light, so I need several of these
circuits, preferably using the minimum number of components.

Another option I would like to explore is to turn the light on and off
using 2 inputs. Say we have in put A and B. If input B is high, when
input A goes high, turn the light on, or leave it on. If input B is
low, when input A goes hight, turn the light off, or leave it off.

What's your goal here? To learn about flip-flops, or to turn a light on
and off? If the latter, just get a push-on-push-off switch. PCs used to
have them - it's a mechanical action, a la a clicker ballpoint pen.

Cheers!
Rich

Hi Chris:

The circuit that you want to build consists of three sections. (1) The
momentary switch must be connected to a debounce circuit. This will create
only one edge when the switch is closed or opened. This is accomplished by
using a resistor and a cap to create a lowpass filter and a buffer logic
device like a 'AND' gate. The secret is to use an additional feed back
resistor that creates hysteresis.

The second section is the flip-flop that is wired to toggle. U can use a
74HC74 D type flip-flop or even a JK flip flop. The 3rd section is the
decode logic. If you want to just toggle an LED then there is no decode
logic. Just connect the output of the flip-flop to an LED or thru an
additional buffer chip. If you want to have 3 LEDS to sequence, just add
another flip-flop and use a couple NAND gates to decode the two outputs of
the two flip flops to generate 3 outputs. Use 74HCXXXX chips because the
crossover threshold voltage is 5volts/2 or 2.5 volts.

Harold



"Chris W" wrote in message
news:2OOQd.63983$jn.59042@lakeread06...
I want a circuit that will turn a light on with the press of a momentary
switch and then turn it back off when the momentary switch is hit again. I
had heard that a flip flop might be the way to go. After some reading, I
have found that a flip flop is a much more complex device than I was lead
to believe. I think a flip flop would some how do the job, but it is going
to take some more reading before I figure out how. If you have been
reading some of my other posts, you know that I want to turn on and off
more than one light, so I need several of these circuits, preferably using
the minimum number of components.
Another option I would like to explore is to turn the light on and off
using 2 inputs. Say we have in put A and B. If input B is high, when
input A goes high, turn the light on, or leave it on. If input B is low,
when input A goes hight, turn the light off, or leave it off.

--
Chris W

Gift Giving Made Easy
Get the gifts you want & give the gifts they want
http://thewishzone.com

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety." -- Benjamin Franklin, 1759
Historical Review of Pennsylvania

Great explanation! Thank you for providing an architectural synopsis of
what's involved.
Peter

"Harold Ryan" wrote in message
...
Hi Chris:

The circuit that you want to build consists of three sections. (1) The
momentary switch must be connected to a debounce circuit. This will create
only one edge when the switch is closed or opened. This is accomplished by
using a resistor and a cap to create a lowpass filter and a buffer logic
device like a 'AND' gate. The secret is to use an additional feed back
resistor that creates hysteresis.

The second section is the flip-flop that is wired to toggle. U can use a
74HC74 D type flip-flop or even a JK flip flop. The 3rd section is the
decode logic. If you want to just toggle an LED then there is no decode
logic. Just connect the output of the flip-flop to an LED or thru an
additional buffer chip. If you want to have 3 LEDS to sequence, just add
another flip-flop and use a couple NAND gates to decode the two outputs of
the two flip flops to generate 3 outputs. Use 74HCXXXX chips because the
crossover threshold voltage is 5volts/2 or 2.5 volts.

Harold

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.

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" wrote in message
...
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 wrote:
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?
:-)


Sadly no. The R/C pink flamingo is destined to remain one of a kind.

--
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.