Electronic SPDT switches

[Abstract Dissonance]

I was thinking if it would be possible to create a completely electronicly
controlled SPDT switch using the following method:


create a conductor that looks like the following



/-------
B /
A------<
B \
\-------


The electrons enter from A and across the conductor there is an electric
field(maybe something like a capacitor).

Then with the right voltage across B to create the electric field one should
be able to "deflect" the electrons into either path? I'm not sure if this
would work in a conductor though as after the field is gone the electrons
would then take both paths... I suppose the field would have to extend to
the branch. Another problem is that it might require very precise control
of the voltage so no current would leak into the wrong path. One "benefit"
would be that without any applied voltage it would act as a divider.

Just a thought.

AD

 

[OBones]

Would not that be an OptoMosfet?

 

[Bob Monsen]

I was thinking if it would be possible to create a completely electronicly

<snip>

You are reinventing the wheel. Look up "Analog Switch". There are also
analog multiplexers, which are made of a few of these. which are more
like what you are proposing.

--
Regards,
Bob Monsen

"I am turned into a sort of machine for observing facts and grinding
out conclusions."
-- Charles Darwin

 

[Rich Grise]

I was thinking if it would be possible to create a completely electronicly
controlled SPDT switch using the following method:

create a conductor that looks like the following

/-------
B /
A------<
B \
\-------

Check http://www.ee.washington.edu/stores/DataSheets/cd4000/cd4066.pdf

Cheers!
Rich

 

[Abstract Dissonance]

<snip>

You are reinventing the wheel. Look up "Analog Switch". There are also
analog multiplexers, which are made of a few of these. which are more
like what you are proposing.

reinventing the wheel? I wasn't inventing nothing just wondering (and
theres nothing wrong with reinventing something either I'm talking about
specifically using electron ballistics to do this and not some other method.
Analog switches uses transistors and such that are based on different
principles?

--
Regards,
Bob Monsen

"I am turned into a sort of machine for observing facts and grinding
out conclusions."
-- Charles Darwin

AD

 

[Abstract Dissonance]

Check http://www.ee.washington.edu/stores/DataSheets/cd4000/cd4066.pdf

Cheers!
Rich

But these are based on semiconductor methods and not electron ballistics?
I'm specifically talking about using electronc ballistic methods.

say I have a gas chamber with two anodes and one cathode and an external
electric field... I Should be able to determine with anode I would like the
current to flow to by controlling that field. Replace the gas with a
conductor and it should probably work too(maybe not though).

I'm not trying to come up with some new switch but just wondering if it
would work or not and if there was anything like it(not the switching itself
but the method)...

AD

 

[Abstract Dissonance]

Would not that be an OptoMosfet?

wouldn't that use light or something?


AD

 

[Kevin White]

I was thinking if it would be possible to create a completely electronicly
controlled SPDT switch using the following method:


create a conductor that looks like the following



/-------
B /
A------<
B \
\-------


The electrons enter from A and across the conductor there is an electric
field(maybe something like a capacitor).

Then with the right voltage across B to create the electric field one should
be able to "deflect" the electrons into either path? I'm not sure if this
would work in a conductor though as after the field is gone the electrons
would then take both paths... I suppose the field would have to extend to
the branch. Another problem is that it might require very precise control
of the voltage so no current would leak into the wrong path. One "benefit"
would be that without any applied voltage it would act as a divider.

Just a thought.

AD

This is essentially what a beam modulation tube does (using a vacuum).

However these types of device cannot exist using a conductor (how do
you create an electric field in a conductor?) or even a semiconductor
(the mean free path is too short for electron inertial effect to be
used).

See http://www.cgs.synth.net/tube/beam.html

A beam modulator is a two anode electron tube with deflection plates to
determine where the electrons go.

kevin

 

[Abstract Dissonance]

This is essentially what a beam modulation tube does (using a vacuum).

However these types of device cannot exist using a conductor (how do
you create an electric field in a conductor?) or even a semiconductor
(the mean free path is too short for electron inertial effect to be
used).

? what causes current to flow in a conductor? the potential is just the
electric field(well, the gradient of the potential...). Its also been shown
that putting an electric field perpendicular to a conductor causes charge
seperation or something like that?

See http://www.cgs.synth.net/tube/beam.html

A beam modulator is a two anode electron tube with deflection plates to
determine where the electrons go.

yeah, I figure its pretty easy to do in a tube but was wondering about a
conductor.

kevin

Thanks,
AD

 

[Mark Fergerson]

But these are based on semiconductor methods and not electron ballistics?
I'm specifically talking about using electronc ballistic methods.

So what? Whether you focus on the contacts (electrodes) or the
crossbar (vacuum/bulk), a switch is a switch.

say I have a gas chamber with two anodes and one cathode and an external
electric field... I Should be able to determine with anode I would like the
current to flow to by controlling that field. Replace the gas with a
conductor and it should probably work too(maybe not though).

How about magnetic instead of electric field as in Hall effect?

I'm not trying to come up with some new switch but just wondering if it
would work or not and if there was anything like it(not the switching itself
but the method)...

Hall effect A/B switch? Probably insufficiently sharp switching
action (too leaky) to be practical or somebody'd be selling them by now.


Mark L. Fergerson

 

[Charlie Edmondson]

? what causes current to flow in a conductor? the potential is just the
electric field(well, the gradient of the potential...). Its also been shown
that putting an electric field perpendicular to a conductor causes charge
seperation or something like that?




yeah, I figure its pretty easy to do in a tube but was wondering about a
conductor.



Thanks,
AD

Ok, AD,
The problem has to deal with field theory, specifically, there are no
magentic fields (or at least gradients) in a conductor. The conductor
CONDUCTS the magnetic field, so, there is no difference in the field on
one side of the conductor as opposed to the other (Yes, I know that is
not exactly correct, but in analogy, it is the best explanation I can
come up with... )

So, no, you can't steer the electrons in a conductor with an external
magnetic field.

Charlie

 

[Abstract Dissonance]

So what? Whether you focus on the contacts (electrodes) or the crossbar
(vacuum/bulk), a switch is a switch.

not really. I'm not interested in switching but just the concept. A big
difference. I didn't ask how to switch anything but if it was possible to do
it the way I described.

How about magnetic instead of electric field as in Hall effect?

I suppose that would work since a magnetic field would extert the same
force(but would just have to rotate it 90 degree's.

Hall effect A/B switch? Probably insufficiently sharp switching action
(too leaky) to be practical or somebody'd be selling them by now.

probably. I figured that since most electrons are going about the same
speed in a conductor that it wouldn't be to hard. I'm not saying its
practical or anything but was just wondering if it was possible to do... I
suppose I could build one or something but I got otherthings to do at the
moment.

Mark L. Fergerson

AD

 

[Abstract Dissonance]

Ok, AD,
The problem has to deal with field theory, specifically, there are no
magentic fields (or at least gradients) in a conductor. The conductor
CONDUCTS the magnetic field, so, there is no difference in the field on
one side of the conductor as opposed to the other (Yes, I know that is not
exactly correct, but in analogy, it is the best explanation I can come up
with... )

So, no, you can't steer the electrons in a conductor with an external
magnetic field.

heh, what about an electric field? (I didn't mention magnetic fields I
read somewhere that if, say, you have a current running through a wire and
you put an electric field across it then the electrons will move to one side
of the conductor...


something like


------------------------- ->
------------------------- ->

where the electrons are flowing in the direction of the arrow..
then put a field across them and it sorta becomes


+++++++++++++++++++++++ ->
----------------------- ->

where one side of the conductor is + and the other is -. Its the same as if
you had a rod with some electrical charge on it and then put an electric
field on it in some way... the charge would position itself across the
conductor(or maybe it needs to be an insulator? ;/) to minimize the total
energy or something like that.


it probably wouldn't be to hard to test it out(though I'm not sure of the
required currents and voltages needed)... i might try it some day just for
fun

Charlie

AD

 

[D. G.]

------------------------- ->
------------------------- ->

where the electrons are flowing in the direction of the arrow..
then put a field across them and it sorta becomes


+++++++++++++++++++++++ ->
----------------------- ->

where one side of the conductor is + and the other is -. Its the same as
if you had a rod with some electrical charge on it and then put an
electric field on it in some way... the charge would position itself
across the conductor(or maybe it needs to be an insulator? ;/) to minimize
the total energy or something like that.


it probably wouldn't be to hard to test it out(though I'm not sure of the
required currents and voltages needed)... i might try it some day just for
fun


AD

May be you should try and share your findings.
But you may need a awesome electric field to deviate the electron in a
conductor. The metal is a good shield against that field.
This is why FETs have been designed, just a tiny electric field is needed to
deviate or block the electron flow.

Dan