Most novel LED flasher ?

[Robert Monsen]

I just built the one you referenced (http://members.shaw.ca/roma/ under
Circuits, #23,) and it works properly with a 2N2222A.

Note that the transistor is 'backwards', ie, the emitter is connected to the
1.5k from V+. Also, I had to crank up my power supply to about 8.5v before
it would start oscillating. Lower than that, it didn't oscillate.

I put the base and emitter on my scope, and it looks like the transistor is
acting like a zener, holding off the current until the voltage gets to about
8.2 volts. At that point, the base starts getting more positive. When the
base gets to .6V, the voltage shoots up briefly, and the emitter voltage
drop to 0.

My guess as to whats happening is that the emitter-base junction is leaking
charge at 8.2V, which is charging up the base. When the base-collector
junction gets forward biased (base up to .6V,) current flows, causing an
avalanche breakdown of some kind in the emitter-base junction. This quickly
discharges the capacitor, so the current drops enough to stop the breakdown
and restart the charging cycle. Its like a UJT oscillator.

Regards

"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.198e065ffb9f073989b27@news.inreach.net...

In article <a7076635.0307271049.10a532c5@posting.google.com>,
bigcat@meeow.co.uk mentioned...
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .


Hi

another one: resistor + capacitor + neon to make a neon flasher.
Supply V should be close to neon Vbreakdown. Now put LED in series
with the R so LED lights during C charging, but goes out as C nears
Vmax.

Of course you dont need the LED, you could in most cases leave that
out.

Which brings to mind the flasher that is shown on some electronics
websites. It is a LED and a C-B junction of a transistor, connected
so that it is reverse biased, and also a capacitor. It's here
http://members.shaw.ca/roma/ under Circuits, #23. The ones I've built
don't work. This is similar to a neon light flasher.



Regards, NT


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Watson A.Name - 'Watt Sun]

In article <lk%Ua.162452$ye4.109491@sccrnsc01>, nospam@nowhere.com
mentioned...

I just built the one you referenced (http://members.shaw.ca/roma/ under
Circuits, #23,) and it works properly with a 2N2222A.

Note that the transistor is 'backwards', ie, the emitter is connected to the
1.5k from V+. Also, I had to crank up my power supply to about 8.5v before
it would start oscillating. Lower than that, it didn't oscillate.

I put the base and emitter on my scope, and it looks like the transistor is
acting like a zener, holding off the current until the voltage gets to about
8.2 volts. At that point, the base starts getting more positive. When the
base gets to .6V, the voltage shoots up briefly, and the emitter voltage
drop to 0.

My guess as to whats happening is that the emitter-base junction is leaking
charge at 8.2V, which is charging up the base. When the base-collector
junction gets forward biased (base up to .6V,) current flows, causing an
avalanche breakdown of some kind in the emitter-base junction. This quickly
discharges the capacitor, so the current drops enough to stop the breakdown
and restart the charging cycle. Its like a UJT oscillator.

I think we just set a new record for lowest parts count - three parts
not counting the LED. An electrolytic capacitor, a current limiting
resistor, and a single standard BJT transistor, not a UJT or PUT.

I just got thru clipping together one with some alli clips. I used a
BC337-25. a 470 ohm resistor, and a 330 uF capacitor. I cranked it up
to 10V, but no cigar. Not even a flicker. When I got to 12V, it
started to slowly flash, longer than 1 second per flash. When I got
to 13V, the flash rate was much faster, somewhere in the 6 to 10 Hz
range. Above that and it stopped flashing and just glowed steady. So
it apparently needs a stable voltage that is very dependent on the
transistor used. Also I found that if I touched the base, it does
weird things like stop oscillating or speeded up. Actually the flash
is more like a throb or pulse, with bright and dim phases, but no
sharply defined on or off. The LED comes on bright quickly, and
tapers off slowly to the dimmest point where it repeats the cycle. I
guess the best way to describe it is a sawtooth wave.

Another warning: do not attempt to use the transistor for its regular
purpose after using it in this circuit. Reverse biasing the E-B
junction to its avalanche mode will cause the transistor's beta to be
seriously degraded. If you do use a transistor for this, it's
probably advisable to cut off the base lead to prevent it from being
used as a regular transistor.

So there you go, two independent verifications that the circuit does
indeed work, and we have set a new low in parts count. The resistor
might be eliminated but at risk of excessive current. I think it
should be left in. Three parts is about as low as it can get with
discrete parts, even with a UJT or PUT.

Regards

"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.198e065ffb9f073989b27@news.inreach.net...
In article <a7076635.0307271049.10a532c5@posting.google.com>,
bigcat@meeow.co.uk mentioned...
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .


Hi

another one: resistor + capacitor + neon to make a neon flasher.
Supply V should be close to neon Vbreakdown. Now put LED in series
with the R so LED lights during C charging, but goes out as C nears
Vmax.

Of course you dont need the LED, you could in most cases leave that
out.

Which brings to mind the flasher that is shown on some electronics
websites. It is a LED and a C-B junction of a transistor, connected
so that it is reverse biased, and also a capacitor. It's here
http://members.shaw.ca/roma/ under Circuits, #23. The ones I've built
don't work. This is similar to a neon light flasher.

Regards, NT

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Da Man]

"Jim Thompson" <Jim-T@analog_innovations.com> wrote in message
news:ii93iv8ps89tvtqijdvdlb7o08s7eef52n@4ax.com...

On Fri, 25 Jul 2003 20:58:53 +0000 (UTC), kensmith@violet.rahul.net
(Ken Smith) wrote:

In article <2c2cf14c.0307251109.c958ad0@posting.google.com>,
Andre <testing_h@yahoo.com> wrote:
Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

1 resistor
1 Thermostat taped to resisitor
-----
2 Parts

--

1 Part: Turn signal flasher ?

Good luck getting enough current through one of those beasts to make it work
with only an plain LED!

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| Jim-T@analog_innovations.com Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

For proper E-mail replies SWAP "-" and "_"

Get Lolita Out of Debt... Add Three Inches to Your Mortgage!

 

[Edward Rosten]

testing_h@yahoo.com (Andre) wrote in message news:<2c2cf14c.0307251109.c958ad0@posting.google.com>...

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

Are you allowed to use an AC supply...?

-Ed

 

[Mike Harrison]

On 28 Jul 2003 06:09:26 -0700, u98ejr@ecs.ox.ac.uk (Edward Rosten) wrote:

testing_h@yahoo.com (Andre) wrote in message news:<2c2cf14c.0307251109.c958ad0@posting.google.com>...


Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .


Are you allowed to use an AC supply...?

-Ed

How about 1 component: - LED in series with a flashing LED!

 

[Grog]

"Andre" <testing_h@yahoo.com> wrote in message
news:2c2cf14c.0307251109.c958ad0@posting.google.com...

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

-Andre

Perhaps a solar panel (2V cell for RED LED), small enough power output so
as not to cook the LED.
The _Flash_ rate may be a bit slow, but it is flashing and
only one component. (not recommended for indoor use..)

Greg the Grog

 

[Andre]

Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message news:<MPG.198e4fbc79dbc407989b28@news.inreach.net>...

In article <lk%Ua.162452$ye4.109491@sccrnsc01>, nospam@nowhere.com
mentioned...
I just built the one you referenced (http://members.shaw.ca/roma/ under
Circuits, #23,) and it works properly with a 2N2222A.

Note that the transistor is 'backwards', ie, the emitter is connected to the
1.5k from V+. Also, I had to crank up my power supply to about 8.5v before
it would start oscillating. Lower than that, it didn't oscillate.

I put the base and emitter on my scope, and it looks like the transistor is
acting like a zener, holding off the current until the voltage gets to about
8.2 volts. At that point, the base starts getting more positive. When the
base gets to .6V, the voltage shoots up briefly, and the emitter voltage
drop to 0.

My guess as to whats happening is that the emitter-base junction is leaking
charge at 8.2V, which is charging up the base. When the base-collector
junction gets forward biased (base up to .6V,) current flows, causing an
avalanche breakdown of some kind in the emitter-base junction. This quickly
discharges the capacitor, so the current drops enough to stop the breakdown
and restart the charging cycle. Its like a UJT oscillator.

I think we just set a new record for lowest parts count - three parts
not counting the LED. An electrolytic capacitor, a current limiting
resistor, and a single standard BJT transistor, not a UJT or PUT.

I just got thru clipping together one with some alli clips. I used a
BC337-25. a 470 ohm resistor, and a 330 uF capacitor. I cranked it up
to 10V, but no cigar. Not even a flicker. When I got to 12V, it
started to slowly flash, longer than 1 second per flash. When I got
to 13V, the flash rate was much faster, somewhere in the 6 to 10 Hz
range. Above that and it stopped flashing and just glowed steady. So
it apparently needs a stable voltage that is very dependent on the
transistor used. Also I found that if I touched the base, it does
weird things like stop oscillating or speeded up. Actually the flash
is more like a throb or pulse, with bright and dim phases, but no
sharply defined on or off. The LED comes on bright quickly, and
tapers off slowly to the dimmest point where it repeats the cycle. I
guess the best way to describe it is a sawtooth wave.

Another warning: do not attempt to use the transistor for its regular
purpose after using it in this circuit. Reverse biasing the E-B
junction to its avalanche mode will cause the transistor's beta to be
seriously degraded. If you do use a transistor for this, it's
probably advisable to cut off the base lead to prevent it from being
used as a regular transistor.

So there you go, two independent verifications that the circuit does
indeed work, and we have set a new low in parts count. The resistor
might be eliminated but at risk of excessive current. I think it
should be left in. Three parts is about as low as it can get with
discrete parts, even with a UJT or PUT.


Regards

"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.198e065ffb9f073989b27@news.inreach.net...
In article <a7076635.0307271049.10a532c5@posting.google.com>,
bigcat@meeow.co.uk mentioned...
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

I did it ! MwahahAHAHAHA !

LM334, 100 uF tant, 100K resistor, 2k7 resistor, white LED .

Beat that !

Tried it with two regulators, both worked fine .

-A

Hi

another one: resistor + capacitor + neon to make a neon flasher.
Supply V should be close to neon Vbreakdown. Now put LED in series
with the R so LED lights during C charging, but goes out as C nears
Vmax.

Of course you dont need the LED, you could in most cases leave that
out.

Which brings to mind the flasher that is shown on some electronics
websites. It is a LED and a C-B junction of a transistor, connected
so that it is reverse biased, and also a capacitor. It's here
http://members.shaw.ca/roma/ under Circuits, #23. The ones I've built
don't work. This is similar to a neon light flasher.

Regards, NT

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Kevin McMurtrie]

In article <2c2cf14c.0307251109.c958ad0@posting.google.com>,
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

-Andre

The parts count is a bit high but mine doesn't need a power supply

http://www.pixelmemory.us/Photos/Nerd/AutoLED.gif

 

[N. Thornton]

Hi

How bout in addition to the LED and battery, a file? Yes, a
woodworking file. Run it across the LED lead and watch the LED flash.

Or if MTTF is not an issue, just LED and small battery, connected with
dry joints. Should get some flashing there, for a bit. Small battery
has enough internal R to not need any resistor. Dont think we can get
a lower parts count than that one. But we could improve the MTTF.

OK, motor in series with LED: some small dc motors go o/c regularly as
they rotate. Thats one component and reliable.

(The avalanche tr has the same parts count as the neon flasher of
course.)


Regards, NT

 

[Andre]

kensmith@violet.rahul.net (Ken Smith) wrote in message news:<bfs5md$8i3$1@blue.rahul.net>...

In article <2c2cf14c.0307251109.c958ad0@posting.google.com>,
Andre <testing_h@yahoo.com> wrote:
Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

1 resistor
1 Thermostat taped to resisitor

1 LDR
2 LEDs (one for flash, one for trigger) .

Uses the tendency of LDRs to have a delayed reaction to light .

-----
2 Parts

--

 

[Watson A.Name - 'Watt Sun]

In article <2c2cf14c.0307281104.3b13cc20@posting.google.com>,
testing_h@yahoo.com mentioned...

Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message news:<MPG.198e4fbc79dbc407989b28@news.inreach.net>...
In article <lk%Ua.162452$ye4.109491@sccrnsc01>, nospam@nowhere.com
mentioned...
I just built the one you referenced (http://members.shaw.ca/roma/ under
Circuits, #23,) and it works properly with a 2N2222A.

Note that the transistor is 'backwards', ie, the emitter is connected to the
1.5k from V+. Also, I had to crank up my power supply to about 8.5v before
it would start oscillating. Lower than that, it didn't oscillate.

I put the base and emitter on my scope, and it looks like the transistor is
acting like a zener, holding off the current until the voltage gets to about
8.2 volts. At that point, the base starts getting more positive. When the
base gets to .6V, the voltage shoots up briefly, and the emitter voltage
drop to 0.

My guess as to whats happening is that the emitter-base junction is leaking
charge at 8.2V, which is charging up the base. When the base-collector
junction gets forward biased (base up to .6V,) current flows, causing an
avalanche breakdown of some kind in the emitter-base junction. This quickly
discharges the capacitor, so the current drops enough to stop the breakdown
and restart the charging cycle. Its like a UJT oscillator.

I think we just set a new record for lowest parts count - three parts
not counting the LED. An electrolytic capacitor, a current limiting
resistor, and a single standard BJT transistor, not a UJT or PUT.

I just got thru clipping together one with some alli clips. I used a
BC337-25. a 470 ohm resistor, and a 330 uF capacitor. I cranked it up
to 10V, but no cigar. Not even a flicker. When I got to 12V, it
started to slowly flash, longer than 1 second per flash. When I got
to 13V, the flash rate was much faster, somewhere in the 6 to 10 Hz
range. Above that and it stopped flashing and just glowed steady. So
it apparently needs a stable voltage that is very dependent on the
transistor used. Also I found that if I touched the base, it does
weird things like stop oscillating or speeded up. Actually the flash
is more like a throb or pulse, with bright and dim phases, but no
sharply defined on or off. The LED comes on bright quickly, and
tapers off slowly to the dimmest point where it repeats the cycle. I
guess the best way to describe it is a sawtooth wave.

Another warning: do not attempt to use the transistor for its regular
purpose after using it in this circuit. Reverse biasing the E-B
junction to its avalanche mode will cause the transistor's beta to be
seriously degraded. If you do use a transistor for this, it's
probably advisable to cut off the base lead to prevent it from being
used as a regular transistor.

So there you go, two independent verifications that the circuit does
indeed work, and we have set a new low in parts count. The resistor
might be eliminated but at risk of excessive current. I think it
should be left in. Three parts is about as low as it can get with
discrete parts, even with a UJT or PUT.


Regards

"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.198e065ffb9f073989b27@news.inreach.net...
In article <a7076635.0307271049.10a532c5@posting.google.com>,
bigcat@meeow.co.uk mentioned...
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

I did it ! MwahahAHAHAHA !

LM334, 100 uF tant, 100K resistor, 2k7 resistor, white LED .

Beat that !

We already have, according to the text that you included, but
apparently didn't read.

Tried it with two regulators, both worked fine .

-A



Hi

another one: resistor + capacitor + neon to make a neon flasher.
Supply V should be close to neon Vbreakdown. Now put LED in series
with the R so LED lights during C charging, but goes out as C nears
Vmax.

Of course you dont need the LED, you could in most cases leave that
out.

Which brings to mind the flasher that is shown on some electronics
websites. It is a LED and a C-B junction of a transistor, connected
so that it is reverse biased, and also a capacitor. It's here
http://members.shaw.ca/roma/ under Circuits, #23. The ones I've built
don't work. This is similar to a neon light flasher.

Regards, NT

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Andre]

Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message

<snippage>

Regards

"Watson A.Name - 'Watt Sun'" <alondra101@hotmail.com> wrote in message
news:MPG.198e065ffb9f073989b27@news.inreach.net...
In article <a7076635.0307271049.10a532c5@posting.google.com>,
bigcat@meeow.co.uk mentioned...
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picked parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

I did it ! MwahahAHAHAHA !

LM334, 100 uF tant, 100K resistor, 2k7 resistor, white LED .

Beat that !

We already have, according to the text that you included, but
apparently didn't read.

I did . My circuit works with any LM334 and is fairly stable .

"Avalanche" transistor oscillators work fine at >12V - should have
specified under 9V . Oops .

Sorry for the confusion there . BTW its quite interesting, the circuit
I designed seems to work fine at 5V but behaves strangely at lower
voltages . (like the LED comes on all the time) .

No doubt it would also work with a small bulb (and without that 2K7
resistor) . Gonna try that too .

-Andre

Tried it with two regulators, both worked fine .

-A



Hi

another one: resistor + capacitor + neon to make a neon flasher.
Supply V should be close to neon Vbreakdown. Now put LED in series
with the R so LED lights during C charging, but goes out as C nears
Vmax.

Of course you dont need the LED, you could in most cases leave that
out.

Which brings to mind the flasher that is shown on some electronics
websites. It is a LED and a C-B junction of a transistor, connected
so that it is reverse biased, and also a capacitor. It's here
http://members.shaw.ca/roma/ under Circuits, #23. The ones I've built
don't work. This is similar to a neon light flasher.

Regards, NT



--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Andre]

Ian Stirling <root@mauve.demon.co.uk> wrote in message news:<bg1kfu$1f1$6$830fa79d@news.demon.co.uk>...

In sci.electronics.misc Kevin McMurtrie <mcmurtri@sonic.net> wrote:
In article <2c2cf14c.0307251109.c958ad0@posting.google.com>,
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

-Andre

Apply tiny current through a blue LED backwards. Now run it under
normal conditions. It will flicker and flash as its damaged crystal
burns away.

Apply a really tiny current through a standard LED.
It will emit photons more or less randomly.
Only need a resistor.

Hmm . Might be useful as a random number generator - apply very low
current to LED and use another LED or photodiode to pick up and
amplify the resultant signal .

-A

 

[Ian Stirling]

In sci.electronics.misc Andre <testing_h@yahoo.com> wrote:

Ian Stirling <root@mauve.demon.co.uk> wrote in message news:<bg1kfu$1f1$6$830fa79d@news.demon.co.uk>...
In sci.electronics.misc Kevin McMurtrie <mcmurtri@sonic.net> wrote:
In article <2c2cf14c.0307251109.c958ad0@posting.google.com>,
testing_h@yahoo.com (Andre) wrote:

Hi group

Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .

-Andre

Apply tiny current through a blue LED backwards. Now run it under
normal conditions. It will flicker and flash as its damaged crystal
burns away.

Apply a really tiny current through a standard LED.
It will emit photons more or less randomly.
Only need a resistor.

Hmm . Might be useful as a random number generator - apply very low
current to LED and use another LED or photodiode to pick up and
amplify the resultant signal .

The problem is how do you tell the real signal from the dark signal of
the photodiode?
Then you need to work out if you need the LED at all.

--
http://inquisitor.i.am/ | mailto:inquisitor@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
<Squawk> Pieces of eight!
<Squawk> Pieces of eight!
<Squawk> Pieces of eight!
<Squawk> Pieces of eight!
<Squawk> Pieces of eight!
<Squawk> Pieces of nine!
<SYSTEM HALTED: parroty error!>

 

[Watson A.Name - 'Watt Sun]

In article <2c2cf14c.0307301108.434ad0b4@posting.google.com>,
testing_h@yahoo.com mentioned...

Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message news:<MPG.199155fca4e3eb9989b32@news.inreach.net>...
In article <2c2cf14c.0307281109.752d37d6@posting.google.com>,
testing_h@yahoo.com mentioned...
Mike Harrison <mike@whitewing.co.uk> wrote in message news:<46eaivss7jpcqe40v31029bk6ud6a0ff6e@4ax.com>...
On 28 Jul 2003 06:09:26 -0700, u98ejr@ecs.ox.ac.uk (Edward Rosten) wrote:

testing_h@yahoo.com (Andre) wrote in message news:<2c2cf14c.0307251109.c958ad0@posting.google.com>...


Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .


Are you allowed to use an AC supply...?

-Ed

How about 1 component: - LED in series with a flashing LED!

How about an opto-isolator, capacitor and LED ?

Surely there must be some configuration that works ?

I don't think that combination will oscillate.

Do you have a problem putting the question mark after the last letter
of the sentence, where it belongs???

What?
Do?
You?
Mean?
By?
That?



-A

Standard convention doesn't have a space between the last letter of a
sentence and the question mark, or the period [dot] for that matter.
Same with the bang [!].

-A


--

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Andre]

Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message news:<MPG.199419eddfeef8f8989b41@news.inreach.net>...

In article <2c2cf14c.0307301108.434ad0b4@posting.google.com>,
testing_h@yahoo.com mentioned...
Watson A.Name - 'Watt Sun' <alondra101@hotmail.com> wrote in message news:<MPG.199155fca4e3eb9989b32@news.inreach.net>...
In article <2c2cf14c.0307281109.752d37d6@posting.google.com>,
testing_h@yahoo.com mentioned...
Mike Harrison <mike@whitewing.co.uk> wrote in message news:<46eaivss7jpcqe40v31029bk6ud6a0ff6e@4ax.com>...
On 28 Jul 2003 06:09:26 -0700, u98ejr@ecs.ox.ac.uk (Edward Rosten) wrote:

testing_h@yahoo.com (Andre) wrote in message news:<2c2cf14c.0307251109.c958ad0@posting.google.com>...


Anyone got below 4 parts + LED (rules :- no chips with more than 4
pins, no PUTs or UJT's, no inductors, no hand picled parts ) ?

So far I have got down to 6 parts + LED, using a regulator IC .


Are you allowed to use an AC supply...?

-Ed

How about 1 component: - LED in series with a flashing LED!

How about an opto-isolator, capacitor and LED ?

Surely there must be some configuration that works ?

I don't think that combination will oscillate.

Do you have a problem putting the question mark after the last letter
of the sentence, where it belongs???

What?
Do?
You?
Mean?
By?
That?



-A

Standard convention doesn't have a space between the last letter of a
sentence and the question mark, or the period [dot] for that matter.
Same with the bang [!].

Gotcha.

-A

-A


--


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Philip Pemberton]

In message <2c2cf14c.0307301105.2f177fcd@posting.google.com>
testing_h@yahoo.com (Andre) wrote:

Ian Stirling <root@mauve.demon.co.uk> wrote in message news:<bg1kfu$1f1$6$830fa79d@news.demon.co.uk>...
Apply a really tiny current through a standard LED.
It will emit photons more or less randomly.
Only need a resistor.
Hmm . Might be useful as a random number generator - apply very low
current to LED and use another LED or photodiode to pick up and
amplify the resultant signal .
I thought the "tried and true" method was to use a 2N3904 with its B-E

junction reverse biased to generate noise? Add a 74ALS04, some Rs and Cs, mix
well and turn the power on. Voila - random TTL noise
See http://willware.net:8080/hw-rng.html for a schematic and some info on the
3904-as-a-noise-source idea

Later.
--
Phil. | Acorn RiscPC600 Mk3, SA202, 64MB, 6GB,
philpem@despammed.com (valid address)| ViewFinder, Ethernet (Acorn AEH62),
http://www.philpem.dsl.pipex.com/ | 8xCD, framegrabber, Teletext
.... Gender is irrelevant. Resistance turns me on.

 

[Mjolinor]

Do you have a problem putting the question mark after the last
letter
of the sentence, where it belongs???

Standard convention doesn't have a space between the last letter of a
sentence and the question mark, or the period [dot] for that matter.
Same with the bang [!].

AFAIK standard convention dictates one question mark to denote a question so
with this in mind is your question more of a question because it has three
question marks?