TV Remote False Triggering Air Purifier!

[[email protected]]

I have an extensive backgroung in building and repairing all
sorts of electronic devices. Like millions of others I spend
more time in front of my Desktop than actually breadboarding
circuits, but I still remember most of what I've learned over
the years.

I recently purchased a very high quaility air purifier. I'm
sure many of you have seen these large drum style air purifiers
that use HEPA filters. That's what I've got. I resisted buying
one for years but my allergies have become increasing worse as
I've grown older, so I really had no choice.

Here's the problem. The up and down volume controls, as well as
the power switch on my TV remote instantly shuts the air purifier
down and resets its programmable timing functions to 12:00 AM.
Naturally I ran out and purchased a different remote. A foolish
thing to do, but if there was chance the problem would go away
I was willing to spend the extra bucks. Unfortunately, it didn't
help.

I tried shielding the IR detector in the air purifier display
with a dark red lens. The same kind you see in convertor boxes,
etc. I put up some carboard around the display to see if it
might deflect the IR pulses away from the detector. I discovered
that the lens would practically have to be opaque before it would
stop reacting to the TV remote. I kept increasing the size of
the cardboard deflectors. The cardboard finally did block the
bouncing signals from TV remote. It also completely stopped the
IR pulses from the air purifier's own remote!

Many years ago a defunct electronics hobby magazine published an
article I wrote about a simple on-off IR controller. Right after
the detector module I included a simple integrator consisting
of a resistor and capacitor. This created a short time lag which
blocked the transmission of spurious signals. If this new air
purifier didn't have 5 year warranty I would open the darn thing
up and insert an integrator with a nice long delay.

Each press of a switch on the TV remote is very short. The pulse
would have no effect on the air purifier's detector if the
integrators time interval were two or three times longer than a
typical press on one of those membrane switches.

I tried moving the purifier around the room to no avail. Nothing
seems to help. I'm hoping someone with more expertise than myself
might come up with a suggestion.

Holophote

 

[NSM]

....
| Here's the problem. The up and down volume controls, as well as
| the power switch on my TV remote instantly shuts the air purifier
| down and resets its programmable timing functions to 12:00 AM.
| Naturally I ran out and purchased a different remote. A foolish
| thing to do, but if there was chance the problem would go away
| I was willing to spend the extra bucks. Unfortunately, it didn't
| help.
....

Tape over the air purifier remote sensor with black electrical tape. Peel it
off when you need to reprogram it.

N

 

[James Sweet]

I have an extensive backgroung in building and repairing all
sorts of electronic devices. Like millions of others I spend
more time in front of my Desktop than actually breadboarding
circuits, but I still remember most of what I've learned over
the years.

I recently purchased a very high quaility air purifier. I'm
sure many of you have seen these large drum style air purifiers
that use HEPA filters. That's what I've got. I resisted buying
one for years but my allergies have become increasing worse as
I've grown older, so I really had no choice.

Here's the problem. The up and down volume controls, as well as
the power switch on my TV remote instantly shuts the air purifier
down and resets its programmable timing functions to 12:00 AM.
Naturally I ran out and purchased a different remote. A foolish
thing to do, but if there was chance the problem would go away
I was willing to spend the extra bucks. Unfortunately, it didn't
help.

I tried shielding the IR detector in the air purifier display
with a dark red lens. The same kind you see in convertor boxes,
etc. I put up some carboard around the display to see if it
might deflect the IR pulses away from the detector. I discovered
that the lens would practically have to be opaque before it would
stop reacting to the TV remote. I kept increasing the size of
the cardboard deflectors. The cardboard finally did block the
bouncing signals from TV remote. It also completely stopped the
IR pulses from the air purifier's own remote!

Many years ago a defunct electronics hobby magazine published an
article I wrote about a simple on-off IR controller. Right after
the detector module I included a simple integrator consisting
of a resistor and capacitor. This created a short time lag which
blocked the transmission of spurious signals. If this new air
purifier didn't have 5 year warranty I would open the darn thing
up and insert an integrator with a nice long delay.

Each press of a switch on the TV remote is very short. The pulse
would have no effect on the air purifier's detector if the
integrators time interval were two or three times longer than a
typical press on one of those membrane switches.

I tried moving the purifier around the room to no avail. Nothing
seems to help. I'm hoping someone with more expertise than myself
might come up with a suggestion.

Holophote

Sounds like you might be out of luck as far as getting the remotes to
cooperate, though you should contact the purifier company and let them know
this is happening because you can't be the only one with a remote that uses
those same codes.

There's a few fixes I can think of, though none of them perfect. One is to
install a switch to disable the IR reciever in the purifier when the TV is
in use, another is to replace the IR LED and reciever with some inexpensive
433MHz RF reciever and transmitter, and another would be to put a
microcontroller between the IR reciever module and the rest of the circuitry
in the air purifier and write some firmware to reciever commands from a
universal remote that doesn't interfere with your TV and output something
compatible with the original.

 

[Sam Goldwasser]

OK. I give up. Exactly why does an air purifier require a remote
control?

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[System Alchemist]

Many years ago a defunct electronics hobby magazine published an
article I wrote about a simple on-off IR controller. Right after
the detector module I included a simple integrator consisting
of a resistor and capacitor. This created a short time lag which
blocked the transmission of spurious signals. If this new air
purifier didn't have 5 year warranty I would open the darn thing
up and insert an integrator with a nice long delay.

Each press of a switch on the TV remote is very short. The pulse
would have no effect on the air purifier's detector if the
integrators time interval were two or three times longer than a
typical press on one of those membrane switches.

You sound a handy sort of chap - it sounds like you need simple
IR repeater, photodetector followed by an IR LED with an RC
filter to get rid of the short pulses from the TV remote. The
IR LED will need mounting in front of the purifiers detector
with black tape (or whatever) so that the purifier can't see
the TV remote.

The repeater may involve a little more complexity but no more
than a nice low power OPAMP.

Useful?
---Paul

 

[NSM]

| OK. I give up. Exactly why does an air purifier require a remote
| control?

Next year: Every remote control will come with a remote control!

N

 

[[email protected]]

I really didn't think anyone would reply to my message.
I apologize for its length. I could have described the
problem using half as many words.

I just want to thank James Sweet, Sam Goldwasser,
System Alchemist, and NSM for their responses.

Sam, I don't have any idea why more and more home
appliances are equipped with overly complex add-ons
like IR remotes, etc. I grew up totally fascinated by
anything techincal, so I guess I shouldn't complain.
Still, this obsession with adding a remote to almost
everything had definitely gone too far.

System Alchemist, your idea about adding a simple
IR repeater is probably the least complex solution to
this problem. I was thinking along the same lines
myself.

This whole thing has got me down in the dumps.
I need that stupid air purifier in my bedroom. My
allergies are so bad I can hardly sleep at night.

Maybe I'll drag myself into my home workshop or the
lab where I work and try to breadboard something that
will do the job.

Holophote

 

[Allodoxaphobia]

OK. I give up. Exactly why does an air purifier require a remote
control?

Here's an even more stoopid example:

I recently had to replace our king size electric blanket.

<OT>
(Only it was not easy: Nobody sells electric blankets anymore! It
took me awhile to realize they are now called "warming blankets"!
Jeez! Just to be politically correct, I suppose, due to the hysteria
of radiation from electrical power lines...)
</OT>

It took me some effort to locate a Dead Simple one that did *NOT* use
remote controls.

I give up, too: "Exactly why does an (electric blanket) require a
remote control?"

Jeez! Think about it for awhile!!

sigh...
Jonesy

 

[James Sweet]

I really didn't think anyone would reply to my message.
I apologize for its length. I could have described the
problem using half as many words.

I just want to thank James Sweet, Sam Goldwasser,
System Alchemist, and NSM for their responses.

Sam, I don't have any idea why more and more home
appliances are equipped with overly complex add-ons
like IR remotes, etc. I grew up totally fascinated by
anything techincal, so I guess I shouldn't complain.
Still, this obsession with adding a remote to almost
everything had definitely gone too far.

System Alchemist, your idea about adding a simple
IR repeater is probably the least complex solution to
this problem. I was thinking along the same lines
myself.

This whole thing has got me down in the dumps.
I need that stupid air purifier in my bedroom. My
allergies are so bad I can hardly sleep at night.

Maybe I'll drag myself into my home workshop or the
lab where I work and try to breadboard something that
will do the job.

Holophote

You could make it simple and just disable the IR reciever and leave the air
purifier on all the time. Mine doesn't have a remote in the first place and
that's exactly what I do, there's no reason to ever turn it off.

 

[BWL]

OK, add this to the list; car stereos with a remote control.

 

[NSM]

| OK, add this to the list; car stereos with a remote control.

You don't really need them on TVs either - if you have children!

N