remote control extender.

J

Johan Wagener

Guest
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote is
used) I can't seem to get the emitting part to work. The units (tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help
 
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote is
used) I can't seem to get the emitting part to work. The units (tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help
Click to expand...
I assume LED0 is the IR transmitting IR LED. I suspected it may have
flashed at least the once bearing in mind that you have a 27R series
resistor and a power supply of 12V. This would give a current of 3-400mA, 3
to 4 times rated current.
 
"Fred" <abuse@hotmail.com> wrote in message
news:3f7724bb$0$10969$fa0fcedb@lovejoy.zen.co.uk...
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote
is
used) I can't seem to get the emitting part to work. The units
(tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help



I assume LED0 is the IR transmitting IR LED. I suspected it may have
flashed at least the once bearing in mind that you have a 27R series
resistor and a power supply of 12V. This would give a current of 3-400mA,
3
to 4 times rated current.
Click to expand...
I did actually lose one LED because of this. It flashed quite a while before
it fried. I changed the value of the resistor to 1k. That however did not
solve the problem concerning the unit not emitting IR
 
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote is
used) I can't seem to get the emitting part to work. The units (tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help
Click to expand...
Try using a camcorder to determine if the transmitter is at least flashing.
I've done this before and it works quite well.

Richard
 
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f7734c3$0$64728@hades.is.co.za...
"Fred" <abuse@hotmail.com> wrote in message
news:3f7724bb$0$10969$fa0fcedb@lovejoy.zen.co.uk...

"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from
http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when
remote
is
used) I can't seem to get the emitting part to work. The units
(tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front
of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help



I assume LED0 is the IR transmitting IR LED. I suspected it may have
flashed at least the once bearing in mind that you have a 27R series
resistor and a power supply of 12V. This would give a current of
3-400mA,
3
to 4 times rated current.



I did actually lose one LED because of this. It flashed quite a while
before
it fried. I changed the value of the resistor to 1k. That however did not
solve the problem concerning the unit not emitting IR


I would change this to 220R to limit the current to 50mA which should be
Click to expand...
safe.

How did you see LED0, the IR led flash. Was it incandescent? I would use a
video camera or a camcorder to check the output of the IR LED.
 
Hi,

Richard's suggestion about the cam corder is the best place to start.
You could also use a web-cam if you have one connected to the PC for
the debugging.

Then, for any project invoving a commercial modulated remote (like the
ones which you are trying to extend), it is *much* better to use a 3
pinIR detector module, rather than discrete components. These devices
have all the electronics required to demodulate the signal very
reliably, in a large variety of ambient lighting conditions, and
reject noise to a great extent. You will get much better results, and
the circuit is as simple, if not simpler.

I could mail you the schematics if you are interested.

Regards,

Anand Dhuru

ardhuru@vsnl.com


"Richard Haendel" <None@nowhere.net> wrote in message news:<n0Idb.162456$3o3.11668855@bgtnsc05-news.ops.worldnet.att.net>...
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote is
used) I can't seem to get the emitting part to work. The units (tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help


Try using a camcorder to determine if the transmitter is at least flashing.
I've done this before and it works quite well.

Richard
Click to expand...
 
"Fred" <abuse@hotmail.com> wrote in message
news:3f7724bb$0$10969$fa0fcedb@lovejoy.zen.co.uk...
"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when remote
is
used) I can't seem to get the emitting part to work. The units
(tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help



I assume LED0 is the IR transmitting IR LED. I suspected it may have
flashed at least the once bearing in mind that you have a 27R series
resistor and a power supply of 12V. This would give a current of 3-400mA,
3
to 4 times rated current.
Click to expand...

Infrared LEDs are often rated for a maximum of 100mA continuous forward DC
current. If the circuit is working properly like it should, then the signal
detected from the remote will be a roughly 38kHz 50% duty cycle squarewave
carrier frequency light signal that is further modulated by the data at
likely less than 50% duty cycle (of the 38kHz carrier) at some frequency
well below the carrier. Usually IR remotes will AM modulate the 38kHz
carrier at some frequency so slow as to be very easily human detectable as
flickering.

So the effective duty cycle the LED should see is likely less than 25%, but
certainly well less than 50%. So even though the 27 ohm resistor limits the
current to something like 3-400mA, when multiplied by the effective duty
cycle the average current through the LED will likely be somewhat less than
100mA. If the circuit is operating properly, the LED will not be
significantly abused...

Unfortunately this circuit is very poorly designed in many respects. The
circuit has novel simplicity, but pays for it in functionality/reliability
and performance.

If the ambient lighting conditions are too high, the circuit will constantly
detect that and turn the output stage on full blast at 100% duty cycle
(plain DC). Thus there certainly exists a real possibility the IR LED could
be damaged by excessive current.

The other really serious problem is the circuit doesn't really try very hard
to keep the incomming and outgoing duty cycles the same. This is probably
why the OP's implementation isn't working. While some IR receiver circuits
might have lax input filters that will respond acceptably to a distorted IR
signal, the OP's IR receiver probably doesn't like the distortion that
likely will be added by the circuit. As a result is balks and doesn't work.

A better designed IR repeater would do something more like this:

An infrared 38kHz receiver IC (such as the Panansonic PNA4602M from Digikey)
should first detect the remote control signal. Since the output of the
receiver IC will be demodulated data, we will need to remodulate the data
onto a new 38kHz carrier. Since the output of the Panasonic is an open
collector output with internal pull up resistor, the output is inverted from
the sent signal. We will need to invert the output signal to get it looking
right again.

A 38kHz 50% duty cycle (fairly high precision, +/-1kHz will likely start
reducing functionality) oscillator will be needed. The oscillator output
should be ANDed with the output of the inverted IR receiver IC output. The
final output should be buffered by a fast switching small MOSFET such as the
BSS138 to drive the LED at pulse currents of up to around 400mA (or perhaps
more if you can insure the average current is less than 100mA). Using
bipolar junction transistors isn't necessarily a good idea for this stage
since they can have fairly long storage times which will distort the signal.
At 38kHz and reasonable drive currents the effect may be minimal, but to be
safe it is easier to just use a MOSFET. Make sure the range extender LED is
not pointed such that any significant amount of IR light will fall on the
detector, otherwise signal feedback will occur and the system will probably
self oscillate.

Even when going to all this trouble the range extender may still not work
since the Panasonic PNA4602M or similar IR receiver IC may distort the
signal enough to cause problems in some cases. In these instances probably
the easiest solution to increasing range is to modify the remote control
itself. Replace the IR LED with one that is more efficient (such as the
Vishay TSAL6100 from Mouser), or use multiple LEDs in parallel (make sure to
pump up the driver power to drive them properly).

To give an idea of what is possible, using six paralleled TSAL6400 LEDs
pulsed at 1A peak currents and a Vishay TSOP1256 receiver IC I was able to
achieve outdoors (at night) data transmission at distances of up to an
estimated 70 meters. Even more range is surely possible with shorter beam
angle LEDs (or more LEDs) and perhaps some other circuit tweaks/improved
optics.
 
would this work?
http://www.epanorama.net/documents/ir/irremote.html

"Fritz Schlunder" <me@privacy.net> wrote in message
news:bl8kf6$8t39d$1@ID-203926.news.uni-berlin.de...
"Fred" <abuse@hotmail.com> wrote in message
news:3f7724bb$0$10969$fa0fcedb@lovejoy.zen.co.uk...

"Johan Wagener" <pil(nospam)@webmail.co.za> wrote in message
news:3f772237$0$64727@hades.is.co.za...
I built the circuit as shown on
http://www.mitedu.freeserve.co.uk/Circuits/Interface/irext.htm.

I could not get hold of the photodiodes they used in this circuit.

I used the following components available from
http://www.fort777.co.za/

Infra red emitter:

Peak wavelength: 940nm
Forward voltage at IF = 20mA: 1.6V
Forward current max.: 100mA
Power dissipation: 100mW
Radiated angle: 30°

Receiver photodiode:

High sensitivity infrared photodiode in side-looking TO92 package.
Black (infrared transparent) epoxy resin package.
Light current typically 75uA at 1000 lux.
Matching transmitter LIR151.
The cathode is the short lead.
ecifications

Peak wavelength: 900nm
Open circuit voltage: 0.35V
Acceptance angle: 120°

The receiving part of my circuit seems to work (led flashes when
remote
is
used) I can't seem to get the emitting part to work. The units
(tv,hi-fi,
ect) simply does nothing even when the diode is placed right in front
of
its
IR.

I can's seem to find the datasheet for the SFH2030 used in the circuit

Please help



I assume LED0 is the IR transmitting IR LED. I suspected it may have
flashed at least the once bearing in mind that you have a 27R series
resistor and a power supply of 12V. This would give a current of
3-400mA,
3
to 4 times rated current.


Infrared LEDs are often rated for a maximum of 100mA continuous forward DC
current. If the circuit is working properly like it should, then the
signal
detected from the remote will be a roughly 38kHz 50% duty cycle squarewave
carrier frequency light signal that is further modulated by the data at
likely less than 50% duty cycle (of the 38kHz carrier) at some frequency
well below the carrier. Usually IR remotes will AM modulate the 38kHz
carrier at some frequency so slow as to be very easily human detectable as
flickering.

So the effective duty cycle the LED should see is likely less than 25%,
but
certainly well less than 50%. So even though the 27 ohm resistor limits
the
current to something like 3-400mA, when multiplied by the effective duty
cycle the average current through the LED will likely be somewhat less
than
100mA. If the circuit is operating properly, the LED will not be
significantly abused...

Unfortunately this circuit is very poorly designed in many respects. The
circuit has novel simplicity, but pays for it in functionality/reliability
and performance.

If the ambient lighting conditions are too high, the circuit will
constantly
detect that and turn the output stage on full blast at 100% duty cycle
(plain DC). Thus there certainly exists a real possibility the IR LED
could
be damaged by excessive current.

The other really serious problem is the circuit doesn't really try very
hard
to keep the incomming and outgoing duty cycles the same. This is probably
why the OP's implementation isn't working. While some IR receiver
circuits
might have lax input filters that will respond acceptably to a distorted
IR
signal, the OP's IR receiver probably doesn't like the distortion that
likely will be added by the circuit. As a result is balks and doesn't
work.

A better designed IR repeater would do something more like this:

An infrared 38kHz receiver IC (such as the Panansonic PNA4602M from
Digikey)
should first detect the remote control signal. Since the output of the
receiver IC will be demodulated data, we will need to remodulate the data
onto a new 38kHz carrier. Since the output of the Panasonic is an open
collector output with internal pull up resistor, the output is inverted
from
the sent signal. We will need to invert the output signal to get it
looking
right again.

A 38kHz 50% duty cycle (fairly high precision, +/-1kHz will likely start
reducing functionality) oscillator will be needed. The oscillator output
should be ANDed with the output of the inverted IR receiver IC output.
The
final output should be buffered by a fast switching small MOSFET such as
the
BSS138 to drive the LED at pulse currents of up to around 400mA (or
perhaps
more if you can insure the average current is less than 100mA). Using
bipolar junction transistors isn't necessarily a good idea for this stage
since they can have fairly long storage times which will distort the
signal.
At 38kHz and reasonable drive currents the effect may be minimal, but to
be
safe it is easier to just use a MOSFET. Make sure the range extender LED
is
not pointed such that any significant amount of IR light will fall on the
detector, otherwise signal feedback will occur and the system will
probably
self oscillate.

Even when going to all this trouble the range extender may still not work
since the Panasonic PNA4602M or similar IR receiver IC may distort the
signal enough to cause problems in some cases. In these instances
probably
the easiest solution to increasing range is to modify the remote control
itself. Replace the IR LED with one that is more efficient (such as the
Vishay TSAL6100 from Mouser), or use multiple LEDs in parallel (make sure
to
pump up the driver power to drive them properly).

To give an idea of what is possible, using six paralleled TSAL6400 LEDs
pulsed at 1A peak currents and a Vishay TSOP1256 receiver IC I was able to
achieve outdoors (at night) data transmission at distances of up to an
estimated 70 meters. Even more range is surely possible with shorter beam
angle LEDs (or more LEDs) and perhaps some other circuit tweaks/improved
optics.
Click to expand...
 
"jibaro" <jibaro@boriquen.com> wrote in message
news:nSLeb.50218$Ci5.1642353@twister.tampabay.rr.com...
would this work?
http://www.epanorama.net/documents/ir/irremote.html
Click to expand...

Well I haven't analyzed the circuit in depth, but yeah it does look like it
definitely has the right idea. As the text indicates it would probably work
better if it were configured for 50% duty cycle.

Also, AFAIK IR remote controls more often operate with a carrier frequency
of 38kHz rather than 40kHz. Certainly both frequencies along with a few
others are used in IR remote applications, but I think the 38kHz is more
popular. I could be wrong.

Nevertheless since the 555 is a poor tolerance RC type oscillator it would
probably be a good idea to use a small frequency trimming pot to allow
yourself to tweak the frequency over the full range including 38kHz and
40kHz to find the frequency of best performance (and perhaps much wider
range still just in case your IR remote runs at something like 56kHz for
instance).

Also the IR LED driver is pretty wimpy in the schematics. I would replace
the output stage 2N2222 with a small MOSFET and reduce the LED series
resistor substantially. The range will certainly be reduced using it as is.
 
Also, AFAIK IR remote controls more often operate with a carrier frequency
of 38kHz rather than 40kHz. Certainly both frequencies along with a few
others are used in IR remote applications, but I think the 38kHz is more
popular. I could be wrong.
Click to expand...
Philips is 36, Sony and a few others 38. I don't know who uses 40. But
the bandfilters are not *that* narrow, a 38 will work reasonably well
with a 36 or a 40.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
PICmicro chips, programmers, consulting
 
"Wouter van Ooijen (www.voti.nl)" <wouter@voti.nl> wrote in message
news:3f7bfeba.223740632@news.xs4all.nl...
Also, AFAIK IR remote controls more often operate with a carrier
frequency
of 38kHz rather than 40kHz. Certainly both frequencies along with a few
others are used in IR remote applications, but I think the 38kHz is more
popular. I could be wrong.

Philips is 36, Sony and a few others 38. I don't know who uses 40. But
the bandfilters are not *that* narrow, a 38 will work reasonably well
with a 36 or a 40.


Wouter van Ooijen

-- ------------------------------------
http://www.voti.nl
PICmicro chips, programmers, consulting
Click to expand...
That circuit, with minor mods for the components I had around, worked with a
Panasonic DVD and a Sony TV. It refused to work with a Scientific Atlanta
cable box and a Harman Kardon AVR110 system. BTW, the DVD and the AVR110 are
the two components (located behind a wood door) that I want to control with
this IR repeater. You could say I'm 50% there.

HarmanKardon has been known to go out of its way on their designs.
Could they be using a strange frenquency to carry the bitstream?
Has anybody measured this?

I do not have the equipment to measure, perhaps someday I will....

Thanks.
 
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