I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

You didn't say how many volts your source is.

In any case, we have to assume you are running
the fans off of DC, prolly 12 volts else the
diode trick won't work. Since we are using DC,
reverse voltage doesn't exist and isn't an issue.
That leaves current rating. At 12 volts and 20W,
your fan will draw 1.67 amperes. So to be safe,
you need at least a 2 ampere diode.

The diode will drop .8 volts across it during
operation, and 1.67 amperes times .8 volts is
1.3 watts of power that the diode will have to
dissipate. That's a reasonable amount in free air.

This should work fine.

http://www.radioshack.com/product/in...77#tabsetBasic

wrote:

I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks


What kind of fans are you using? 20W sounds like AC motors. If so,
you do not want diodes. What you need is the right switch, or a two
pole four postion rotary switch wired to give the function you want.
Another way is the switch used in range hoods, or just a pair of SPST
switches, one for each fan. You may need a metal flap to block the
unused fan to keep the hot air from being pushed back through it.


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

On Jan 24, 12:07*pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. *I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. *I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. *I am having a bit of trouble with
selecting a diode. *I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. *The fans draw 20W each. *For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: *http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. *Recommendations please. *Once I complete this
task I can get down to forming the sheetmetal. *Thanks

I might be missing something here , but why not just use 2 spst
switches and then you can run either fan , both fans, or none.

wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page:
http://www.radioshack.com/family/ind...goryId=2032269 I am
having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

You don't neet a diode, you need a switch. Specifically, a DPDT Center-off
switch.

Ground out both fans, and use the switch to switch the hot. Here is a
picture of how you would wire it up:

http://img510.imageshack.us/img510/9725/dpdtfan.jpg

As you didn't provide specifications for your fans, determining the correct
ratings (and size and mounting hole) for your switch is up to you.
Personally, I would order it online and get the switch you want, instead of
buying whatever radio shack has laying around made by God only knows who.

Jon

On Mon, 24 Jan 2011 13:17:46 -0800, "Jon Danniken"
wrote:

wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page:
http://www.radioshack.com/family/ind...goryId=2032269 I am
having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

You don't neet a diode, you need a switch. Specifically, a DPDT Center-off
switch.

Ground out both fans, and use the switch to switch the hot. Here is a
picture of how you would wire it up:

http://img510.imageshack.us/img510/9725/dpdtfan.jpg

As you didn't provide specifications for your fans, determining the correct
ratings (and size and mounting hole) for your switch is up to you.
Personally, I would order it online and get the switch you want, instead of
buying whatever radio shack has laying around made by God only knows who.

Jon



IF he is running DC fans a center off double throw single pole switch
will work with a diode. With the diode connected between the positive
connections, and the negatives tied together, putting power to one
side of the diode will run the one motor, with current to the other
fan being blocked by the diode.
Put power to the other side of the diode and the first fan will run
through the diode, and the second fan will run full power.
Not a bad way to do things - and the diode just needs to handle
adequate voltage and current for one motor. If the fans are 12 volt,
he needs a 25 voltpiv, 2 amp diode at the very minimum. I'd use a 50
volt 5 or 10 amp diode if I was doing it. The 3 amp barrel diode on
the rat-shack site would do the job. It doesn't say on that site, but
it is a 50 volt PIV diode. (some are actually 200PIV) - look up
ecg-5800 for 50 volt,5801 is 100 volt, 5802 is 200 volt.
A 6 amp diode would be a 5850, 5854, or 5855 and would be a
stud-mount.(DO4 case)

Inscribed thus:

I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page:
http://www.radioshack.com/family/ind...goryId=2032269 I am
having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

Go grab an old computer PSU and strip one of the low voltage diodes
out !

--
Best Regards:
Baron.

Jon Danniken wrote:
You don't neet a diode, you need a switch. Specifically, a DPDT Center-off
switch.

Often described in the online catalogs as a DPDT ON-OFF-ON.

Bob

wrote:
IF he is running DC fans a center off double throw single pole switch
will work with a diode.

Yes, that would work. I personally would not consider it a satisfactory
solution because it introduces an extra component, additional mounting
issues, additional repair considerations, and it drops at least 0.7 volts
which is lost as heat.

With a switch you have a one component solution which follows the KISS
principle, resulting in a simple and elegant solution. One switch and it's
done.

Jon

On Mon, 24 Jan 2011 13:05:25 -0800 (PST), beecrofter
wrote:

On Jan 24, 12:07*pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. *I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. *I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. *I am having a bit of trouble with
selecting a diode. *I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. *The fans draw 20W each. *For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: *http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. *Recommendations please. *Once I complete this
task I can get down to forming the sheetmetal. *Thanks

Fan specs? If they're AC fans (as the 20W suggests) then forget it,
just get a more appropriate switch eg. DPDT with center-off. Diodes
will fry the fans.

Bob Engelhardt wrote:

Jon Danniken wrote:
? You don't neet a diode, you need a switch. Specifically, a DPDT Center-off
? switch.

Often described in the online catalogs as a DPDT ON-OFF-ON.


How will that turn on both fans at once?


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

Michael A. Terrell wrote:
Bob Engelhardt wrote:
Jon Danniken wrote:
? You don't neet a diode, you need a switch. Specifically, a DPDT Center-off
? switch.

Often described in the online catalogs as a DPDT ON-OFF-ON.


How will that turn on both fans at once?


In Jon's diagram, the "down" position turns both on. Bob

Bob Engelhardt wrote:
Jon Danniken wrote:
You don't neet a diode, you need a switch. Specifically, a DPDT
Center-off switch.

Often described in the online catalogs as a DPDT ON-OFF-ON.

Aye, I also notice some of them say DPDT ON-NONE-ON.

Jon

On Mon, 24 Jan 2011 16:13:19 -0800, the renowned "Jon Danniken"
wrote:

Bob Engelhardt wrote:
Jon Danniken wrote:
You don't neet a diode, you need a switch. Specifically, a DPDT
Center-off switch.

Often described in the online catalogs as a DPDT ON-OFF-ON.

Aye, I also notice some of them say DPDT ON-NONE-ON.

Jon


It could also be done with a 2-pole 3-position (DP3T) slide switch,
which could be wired to give off-lo-hi in that (or any other) order.

Eg.
http://www.allelectronics.com/make-a...-SWITCH/1.html

33 cents each. ;-) Too bad there's no easy way to mount it to a
panel.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Jan 24, 7:13*pm, "Jon Danniken"
wrote:
Bob Engelhardt wrote:
..
Often described in the online catalogs as a DPDT ON-OFF-ON.

Aye, I also notice some of them say DPDT ON-NONE-ON.
Jon

That's the two position version without a center OFF position.

jsw

On 1/24/2011 7:16 PM, Jim Wilkins wrote:

On Jan 24, 7:13 pm, "Jon Danniken"
wrote:
Bob Engelhardt wrote:
..
Often described in the online catalogs as a DPDT ON-OFF-ON.

Aye, I also notice some of them say DPDT ON-NONE-ON.
Jon

That's the two position version without a center OFF position.

jsw


This is exactly the switch function of an ordinary, every day 3-way lamp
switch available at most any hardware store for a couple of bucks.

Off-Low-Medium-High switch positions correspond to no motor, one motor,
other motor and both motors.

Carla

It's all fun and games until she asks if you've ever seen "The Crying Game."

On 1/24/2011 9:07 AM, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

is there any reason why you don't use a DPDT switch ? no diodes, works
with AC or DC fans

--
www.wbnoble.com

Jim Wilkins wrote:
"Jon Danniken" wrote:

Aye, I also notice some of them say DPDT ON-NONE-ON.

That's the two position version without a center OFF position.

Thanks Jim, now I know that.

Jon

On Mon, 24 Jan 2011 21:43:15 -0800, Carla Fong
wrote:

On 1/24/2011 7:16 PM, Jim Wilkins wrote:

On Jan 24, 7:13 pm, "Jon Danniken"
wrote:
Bob Engelhardt wrote:
..
Often described in the online catalogs as a DPDT ON-OFF-ON.

Aye, I also notice some of them say DPDT ON-NONE-ON.
Jon

That's the two position version without a center OFF position.

jsw


This is exactly the switch function of an ordinary, every day 3-way lamp
switch available at most any hardware store for a couple of bucks.

Off-Low-Medium-High switch positions correspond to no motor, one motor,
other motor and both motors.

Carla

Good catch!

On Jan 25, 12:43*am, Carla Fong wrote:
...
This is exactly the switch function of an ordinary, every day 3-way lamp
switch available at most any hardware store for a couple of bucks.

Carla

Yabbut those stores never have the right drill to mount those wall
switches neatly in an aluminum panel.

jsw,
who has wired a motorcycle with duct-taped light switches to get it
running.

On Mon, 24 Jan 2011 21:59:20 -0800, Bill Noble
wrote:

On 1/24/2011 9:07 AM, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

is there any reason why you don't use a DPDT switch ? no diodes, works
with AC or DC fans
He would need a dpdt center off switch. And exactly haw are you going
to select ONE motor on one position, and 2 on the other with the
motors in parallell? I can see if you tie the commons together, and
tie both terninals of one side together, then feed the motors from the
2 terminals on one end of the switch - for 1 motor switch to the
position that connects the common to the bridged terminals and the
empty non-bridged terminal. For both to the position that connects the
common to the occupied non-bridged and the bridged terminals. Other
end of both motors tied together to the other (neuatral) line.
Any other way?

wrote:

He would need a dpdt center off switch. And exactly haw are you going
to select ONE motor on one position, and 2 on the other with the
motors in parallell? I can see if you tie the commons together, and
tie both terninals of one side together, then feed the motors from the
2 terminals on one end of the switch - for 1 motor switch to the
position that connects the common to the bridged terminals and the
empty non-bridged terminal. For both to the position that connects the
common to the occupied non-bridged and the bridged terminals. Other
end of both motors tied together to the other (neuatral) line.
Any other way?

http://www.grumpyoldgeek.com/images/fan.jpg

On Tue, 25 Jan 2011 10:37:58 -0800, Jim Stewart
wrote:

wrote:

He would need a dpdt center off switch. And exactly haw are you going
to select ONE motor on one position, and 2 on the other with the
motors in parallell? I can see if you tie the commons together, and
tie both terninals of one side together, then feed the motors from the
2 terminals on one end of the switch - for 1 motor switch to the
position that connects the common to the bridged terminals and the
empty non-bridged terminal. For both to the position that connects the
common to the occupied non-bridged and the bridged terminals. Other
end of both motors tied together to the other (neuatral) line.
Any other way?

http://www.grumpyoldgeek.com/images/fan.jpg
Basically what I said. You just moved the one jumper - has the same
effect.

OT, but worth mentioning.

Obama is on Fox on one TV and I'm recording Lynyrd Skynyrd singing God
and Guns on PBS on the other one,

jsw

On 1/25/2011 10:07 AM, wrote:
On Mon, 24 Jan 2011 21:59:20 -0800, Bill Noble
wrote:

On 1/24/2011 9:07 AM, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. I have a 3 position switch
(0, 1 , 2) so that I can run either one or two fans. I need a "check
valve" (diode?) to prevent both of the fans from running when the
switch is set for a single fan. I am having a bit of trouble with
selecting a diode. I did a quick google search that leads me to
believe that the diode needs to be specified based on reverse current
to be blocked and the voltage. The fans draw 20W each. For such a
cheap simple part, I wish to buy it at Radio Shack but looking at
their web page: http://www.radioshack.com/family/ind...goryId=2032269
I am having difficulty trying to pick one - many of the diodes do not
even show a spec sheet. Recommendations please. Once I complete this
task I can get down to forming the sheetmetal. Thanks

is there any reason why you don't use a DPDT switch ? no diodes, works
with AC or DC fans
He would need a dpdt center off switch. And exactly haw are you going
to select ONE motor on one position, and 2 on the other with the
motors in parallell? I can see if you tie the commons together, and
tie both terninals of one side together, then feed the motors from the
2 terminals on one end of the switch - for 1 motor switch to the
position that connects the common to the bridged terminals and the
empty non-bridged terminal. For both to the position that connects the
common to the occupied non-bridged and the bridged terminals. Other
end of both motors tied together to the other (neuatral) line.
Any other way?

first, I don't recall a mention of off, but yes, a center off switch is
the way to go. Wire white to both motors. Wire black to both center
terminals of the switch. Connect motor 1 to pole 1 terminal 1. Connect
motor 2 to pole 2, both terminals.

How hard it this?

--
www.wbnoble.com

wrote:
On Tue, 25 Jan 2011 10:37:58 -0800, Jim
wrote:

wrote:

He would need a dpdt center off switch. And exactly haw are you going
to select ONE motor on one position, and 2 on the other with the
motors in parallell? I can see if you tie the commons together, and
tie both terninals of one side together, then feed the motors from the
2 terminals on one end of the switch - for 1 motor switch to the
position that connects the common to the bridged terminals and the
empty non-bridged terminal. For both to the position that connects the
common to the occupied non-bridged and the bridged terminals. Other
end of both motors tied together to the other (neuatral) line.
Any other way?

http://www.grumpyoldgeek.com/images/fan.jpg
Basically what I said. You just moved the one jumper - has the same
effect.

Well, I read your paragraph 3 times and still
couldn't understand what you were saying.

Nor could I decide whether you were asking a
real or rhetorical question.

In any case, this sort of thing begs for a
picture or drawing.

On Jan 26, 11:57*am, Jim Stewart wrote:
.
In any case, this sort of thing begs for a
picture or drawing.

Fixed pitch font.
0 is a switch terminal, / is a closed switch contact.
Fan 1 is connected to two diagonally opposite terminals.

Fan 1 only:
fan1--0 0
/ /
power-0--0

fan2--0 0--fan1


Both fans:
fan1--0 0

power-0--0
\ \
fan2--0 0--fan1

jsw

Jim Wilkins wrote:
On Jan 26, 11:57 am, Jim wrote:
.
In any case, this sort of thing begs for a
picture or drawing.

That's why I linked to this picture when I
replied:

http://www.grumpyoldgeek.com/images/fan.jpg


Fixed pitch font.
0 is a switch terminal, / is a closed switch contact.
Fan 1 is connected to two diagonally opposite terminals.

Fan 1 only:
fan1--0 0
/ /
power-0--0

fan2--0 0--fan1


Both fans:
fan1--0 0

power-0--0
\ \
fan2--0 0--fan1

jsw

On Jan 24, 12:07*pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. *

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

On Wed, 26 Jan 2011 15:15:24 -0800 (PST), wrote:

On Jan 24, 12:07Â*pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. Â*

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Diodes do not work as switches in AC circuits. You will need a proper
switch to do the job on AC.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

On Wed, 26 Jan 2011 22:08:10 -0500, the renowned
wrote:

On Wed, 26 Jan 2011 15:15:24 -0800 (PST), wrote:

On Jan 24, 12:07*pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert. *

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Diodes do not work as switches in AC circuits. You will need a proper
switch to do the job on AC.

The only way that comes to mind with AC would be to add an AC-coil
SPST NO relay and I think a double pole switch will be easier and
cheaper.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

I hope this doesn't sound snide, it's not intended to be. Please look
at what a diode does. There are certainly diodes available to operate
at AC mains voltages, and they are cheap. But what a diode does is not
what you need done. There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. The question you asked shows a
basic misunderstanding of AC current and how AC motors work. Reading
even the most basic text will help you understand these responses.

A switch that fits the existing hole will not be a problem.

--
www.wbnoble.com

On Wed, 26 Jan 2011 21:32:03 -0800, Bill Noble
wrote:

On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

I hope this doesn't sound snide, it's not intended to be. Please look
at what a diode does. There are certainly diodes available to operate
at AC mains voltages, and they are cheap. But what a diode does is not
what you need done. There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. The question you asked shows a
basic misunderstanding of AC current and how AC motors work. Reading
even the most basic text will help you understand these responses.

A switch that fits the existing hole will not be a problem.
If he was running DC fans, a diode does EXACTLY what he wants to do -
but a diode cannot do that job on AC, no matter what kind of diode you
manage to get your hands on.

On Jan 27, 6:28*pm, wrote:
On Wed, 26 Jan 2011 21:32:03 -0800, Bill Noble



wrote:
On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. *The fans are 120v. *I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. *I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. *I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). *Thanks again.

I hope this doesn't sound snide, it's not intended to be. *Please look
at what a diode does. *There are certainly diodes available to operate
at AC mains voltages, and they are cheap. *But what a diode does is not
what you need done. *There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. *The question you asked shows a
basic misunderstanding of AC current and how AC motors work. *Reading
even the most basic text will help you understand these responses.

*A switch that fits the existing hole will not be a problem.

*If he was running DC fans, a diode does EXACTLY what he wants to do -
but a diode cannot do that job on AC, no matter what kind of diode you
manage to get your hands on.


This Whole Thread is a massive.. Who Cares!
The OP was a Hit and run, and hasn't been back anyway.

But a lot of good discussion, and solutions, and lateral and forward
thinking.

Cross-Slide wrote:

On Jan 27, 6:28 pm, wrote:
On Wed, 26 Jan 2011 21:32:03 -0800, Bill Noble



wrote:
On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

I hope this doesn't sound snide, it's not intended to be. Please look
at what a diode does. There are certainly diodes available to operate
at AC mains voltages, and they are cheap. But what a diode does is not
what you need done. There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. The question you asked shows a
basic misunderstanding of AC current and how AC motors work. Reading
even the most basic text will help you understand these responses.

A switch that fits the existing hole will not be a problem.

If he was running DC fans, a diode does EXACTLY what he wants to do -
but a diode cannot do that job on AC, no matter what kind of diode you
manage to get your hands on.

This Whole Thread is a massive.. Who Cares!
The OP was a Hit and run, and hasn't been back anyway.


Yes, he was. In fact, the orginal message and his reply are quoted
in your message.


But a lot of good discussion, and solutions, and lateral and forward
thinking.


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

On Jan 27, 8:28*pm, "Michael A. Terrell"
wrote:
Cross-Slide wrote:

On Jan 27, 6:28 pm, wrote:
On Wed, 26 Jan 2011 21:32:03 -0800, Bill Noble

wrote:
On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. *The fans are 120v. *I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. *I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. *I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). *Thanks again.

I hope this doesn't sound snide, it's not intended to be. *Please look
at what a diode does. *There are certainly diodes available to operate
at AC mains voltages, and they are cheap. *But what a diode does is not
what you need done. *There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. *The question you asked shows a
basic misunderstanding of AC current and how AC motors work. *Reading
even the most basic text will help you understand these responses.

*A switch that fits the existing hole will not be a problem.

*If he was running DC fans, a diode does EXACTLY what he wants to do -
but a diode cannot do that job on AC, no matter what kind of diode you
manage to get your hands on.

This Whole Thread is a massive.. Who Cares!
The OP was a Hit and run, and hasn't been back anyway.

* *Yes, he was. *In fact, the orginal message and his reply are quoted
in your message.


I stand corrected!

Cross-Slide wrote:

On Jan 27, 8:28 pm, "Michael A. Terrell"
wrote:
Cross-Slide wrote:

On Jan 27, 6:28 pm, wrote:
On Wed, 26 Jan 2011 21:32:03 -0800, Bill Noble

wrote:
On 1/26/2011 3:15 PM, wrote:
On Jan 24, 12:07 pm, wrote:
I am fabricating a small box that will house a couple of "muffin" fans
to direct air behind a fireplace insert.

Thanks to all of you for the responses. The fans are 120v. I just
assumed that there were diodes available for line voltage - they make
hydraulic check valves for all sorts of pressures.

Looks like I need to find a different switch. I bought the switch a
couple of years ago for this (future) project and suddenly when I got
the meter out to check the terminals, I realised that both fans were
going to run on both fan settings. I'll look into the switches
mentioned and see how I can package them (the hole is already made -
duh!). Thanks again.

I hope this doesn't sound snide, it's not intended to be. Please look
at what a diode does. There are certainly diodes available to operate
at AC mains voltages, and they are cheap. But what a diode does is not
what you need done. There are some very simple, easy to read books and
articles about basic electricity, that explain AC and DC and some
essential concepts - one of my favorite was a military training manual
which is probably available in PDF. The question you asked shows a
basic misunderstanding of AC current and how AC motors work. Reading
even the most basic text will help you understand these responses.

A switch that fits the existing hole will not be a problem.

If he was running DC fans, a diode does EXACTLY what he wants to do -
but a diode cannot do that job on AC, no matter what kind of diode you
manage to get your hands on.

This Whole Thread is a massive.. Who Cares!
The OP was a Hit and run, and hasn't been back anyway.

Yes, he was. In fact, the orginal message and his reply are quoted
in your message.


I stand corrected!


Then sit down! You're blocking everyone's view. ;-)


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

Coooool way coooool , switching transistors ,
pulll down

the fan , to ground ... no diodes ..



BTW create stuf @ googlegroups . com no noise , its
moderated ..

If its a technical problem its OK in

this news group ,, but i dont know how

to access my news group , help !

give me your email adress , ill add if i knew
how ..


yes , i can add addresses , but i can access the
account ,

cant find it nor figure it , yet im the creator !


I promise a huge database of tech stuff .

for got to post the easier way .

buy Home Depot curly compact flour bulbs ,

transistors , diodes high voltage caps inductors ,

worth far more than the $1

I got 1000 the hard way , sawing off the
base


and cutting the PCB and re wiring the 13003 /
BLD123a high

voltage NPN's parallel , for 300 watts from a
23watt CFL .



News Groups ? High tech moderated createstuf @
Googlegroups . com

I need help to access it , and yet i created
it , give help pls