Hi

I have a Fellowes PS-62C shredder like this:
http://www.argos.co.uk/webapp/wcs/st...chTerms=ps+62c

Suddenly, without warning, the sensor which detects a sheet of paper
stopped working, so that the shredder is always on (unless I switch it
off manually). The sensor looks like some kind of IR thing. I've
cleaned it, but that hasn't helped.

Any ideas?

Cheers!

Martin

writes:

Hi

I have a Fellowes PS-62C shredder like this:
http://www.argos.co.uk/webapp/wcs/st...chTerms=ps+62c

Suddenly, without warning, the sensor which detects a sheet of paper
stopped working, so that the shredder is always on (unless I switch it
off manually). The sensor looks like some kind of IR thing. I've
cleaned it, but that hasn't helped.

These sorts of sensors typically have an IRLED and photodiode. If transmission,
they will be on opposite sides of the paper path. If by reflection, it will be
a single sensor assembly. If you can identify the photodiode pins and disconnect
one, that should stop the shredder if it's a sensor problem.

Can you take pics of the sensor?

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

On 20 Jun, 00:25, Sam Goldwasser wrote:

These sorts of sensors typically have an IRLED and photodiode. If transmission,
they will be on opposite sides of the paper path. If by reflection, it will be
a single sensor assembly. If you can identify the photodiode pins and disconnect
one, that should stop the shredder if it's a sensor problem.

Can you take pics of the sensor?

Hi Sam,

I can't get a good pic of it, but it would seem that on both sides of
the paper path there is something resembling an LED, although each one
looks slightly different. There is no reflector involved so far as I
can tell.

What I would like to do is get the sensor working again. The shredder
is designed with an "on/off" switch. When the switch is set to on (and
the sensor is working properly) it is in fact in standby until
triggered by a sheet of paper detected by the sensor. With *my*
shredder on that setting the motor runs continuously. However, I can
easily stop it just by manually flicking the switch to off. I just
like having the sensor working.

Cheers!

Martin

wrote in message
oups.com...
Hi

I have a Fellowes PS-62C shredder like this:
http://www.argos.co.uk/webapp/wcs/st...chTerms=ps+62c

Suddenly, without warning, the sensor which detects a sheet of paper
stopped working, so that the shredder is always on (unless I switch it
off manually). The sensor looks like some kind of IR thing. I've
cleaned it, but that hasn't helped.

Any ideas?

Cheers!

Martin


Instead of the sensor, I would look at the triac or relay that drives the
motor. It probably failed in the On state as those parts often do.

The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

C




wrote:
Hi

I have a Fellowes PS-62C shredder like this:
http://www.argos.co.uk/webapp/wcs/st...chTerms=ps+62c

Suddenly, without warning, the sensor which detects a sheet of paper
stopped working, so that the shredder is always on (unless I switch it
off manually). The sensor looks like some kind of IR thing. I've
cleaned it, but that hasn't helped.

Any ideas?

Cheers!

Martin

On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

On Wed, 20 Jun 2007 04:47:04 -0700, "
wrote:

On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!


--
- René

On Jun 20, 3:19 pm, René wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

MBQ

Martin Pentreath writes:

On 20 Jun, 00:25, Sam Goldwasser wrote:

These sorts of sensors typically have an IRLED and photodiode. If transmission,
they will be on opposite sides of the paper path. If by reflection, it will be
a single sensor assembly. If you can identify the photodiode pins and disconnect
one, that should stop the shredder if it's a sensor problem.

Can you take pics of the sensor?

Hi Sam,

I can't get a good pic of it, but it would seem that on both sides of
the paper path there is something resembling an LED, although each one
looks slightly different. There is no reflector involved so far as I
can tell.

What I would like to do is get the sensor working again. The shredder
is designed with an "on/off" switch. When the switch is set to on (and
the sensor is working properly) it is in fact in standby until
triggered by a sheet of paper detected by the sensor. With *my*
shredder on that setting the motor runs continuously. However, I can
easily stop it just by manually flicking the switch to off. I just
like having the sensor working.

First test: Try shining a bright light into the area of the sensor, or directly if
it's apart. Even with a filter to block visible, enough should get through and
the machine should turn off. A good flashlight might do it. I doubt it's any more
sophisticated than simply looking for light across the paper path.

If this works, then you should be able to identify the IR LED. Then, it's a matter
of determining if the IR LED isn't working or isn't being driven.

If the test doesn't work, the sensor may be bad.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

wrote:

On Jun 20, 3:19 pm, René wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

Well practically you would be ill advised to use a generator as an
electrical motor but there is in essence no functional difference
between the two. So with a LED a current leads to light being emitted,
there is no theoretical reason why if I shine a strong enough light of
the right wavelength on a LED I won't get a current out of it. In
practical terms if I want to use my LED in this way I will get more
efficent performance if I optimise it for this function. But this does
not change the underlying reversibility of the physics.

Peter

--
Add my middle initial to email me. It has become attached to a country
www.the-brights.net

" writes:

On Jun 20, 3:19 pm, Ren=E9 wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off =
it
is the sensor which can be sourced anywhere. If it doesn't shut off, =
it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

They do work but rarely used in anything like this. Photodiodes are used with
IR LEDs.

But a comment in another post that it may not be the sensor also needs to be
pursued. That sensor drives a triac (probably) and they do fail shorted.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Many thanks for all the advice. Mysteriously, the thing is now working
again as it should. I guess it will probably go again soon, but now I
know what to do.

Cheers!

Martin

Curiouser and curiouser - it was woking fine while the sun was shining
into my study, but it stopped working again as the light began to fade
indoors this evening. It works fine if I keep put my desklamp near it!
I guess this does mean that the IR LED is failing. Or maybe it's just
afraid of the dark, and likes to keep its motor going to scare off the
monsters.

Peter Ashby inscribed thus:

wrote:

On Jun 20, 3:19 pm, René wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is
the sensor
is to shine a bright flashlight onto the non-IR LED. If it
shuts off it
is the sensor which can be sourced anywhere. If it doesn't
shut off, it
isn't the sensor. Sensors are a major problem with Fellowes &
I always keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

Well practically you would be ill advised to use a generator as an
electrical motor but there is in essence no functional difference
between the two. So with a LED a current leads to light being
emitted, there is no theoretical reason why if I shine a strong
enough light of the right wavelength on a LED I won't get a current
out of it. In practical terms if I want to use my LED in this way I
will get more efficent performance if I optimise it for this
function. But this does not change the underlying reversibility of
the physics.

Peter

--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Actually I have practical experience of this phenomena !

I used an LED as a noise source, and it worked very well, but had real
problems suppressing the 50 Hz hum on the signal, until I realised
that the hum amplitude changed when I stood between it and the
fluorescent light !
--
Best Regards:
Baron.

Baron wrote:

Peter Ashby inscribed thus:

wrote:

On Jun 20, 3:19 pm, René wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is
the sensor
is to shine a bright flashlight onto the non-IR LED. If it
shuts off it
is the sensor which can be sourced anywhere. If it doesn't
shut off, it
isn't the sensor. Sensors are a major problem with Fellowes &
I always keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

Well practically you would be ill advised to use a generator as an
electrical motor but there is in essence no functional difference
between the two. So with a LED a current leads to light being
emitted, there is no theoretical reason why if I shine a strong
enough light of the right wavelength on a LED I won't get a current
out of it. In practical terms if I want to use my LED in this way I
will get more efficent performance if I optimise it for this
function. But this does not change the underlying reversibility of
the physics.

Peter

--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Actually I have practical experience of this phenomena !

I used an LED as a noise source, and it worked very well, but had real
problems suppressing the 50 Hz hum on the signal, until I realised
that the hum amplitude changed when I stood between it and the
fluorescent light !

Did you rule out that you were blocking a magnetic signal?

Peter
--
Add my middle initial to email me. It has become attached to a country
www.the-brights.net

Martin Pentreath wrote:

Curiouser and curiouser - it was woking fine while the sun was shining
into my study, but it stopped working again as the light began to fade
indoors this evening. It works fine if I keep put my desklamp near it!
I guess this does mean that the IR LED is failing. Or maybe it's just
afraid of the dark, and likes to keep its motor going to scare off the
monsters.

Or there is a dodgy connection, when the unit is warm the metal expands
and makes the connection, when it cools the connection is broken. I had
this with an incandescent bulb. It blew, but then it came back on then
went off, then back on, then off etc. The filament had broken, when it
cooled it contracted and reconnected, at which point it heated and broke
the connection etc.

Peter
--
Add my middle initial to email me. It has become attached to a country
www.the-brights.net

"Martin Pentreath" wrote in message
oups.com...
Curiouser and curiouser - it was woking fine while the sun was shining
into my study, but it stopped working again as the light began to fade
indoors this evening. It works fine if I keep put my desklamp near it!
I guess this does mean that the IR LED is failing. Or maybe it's just
afraid of the dark, and likes to keep its motor going to scare off the
monsters.


Yep, either the LED or the power source to it. Sounds like you're close.

You're right.... meant to say shine the light on the sensor. It's tough
getting old and having brain farts and finger farts at the same time.
Don't even have a dog to blame it on.

C




wrote:
On Jun 20, 6:00 am, C wrote:

The sensor is just an IR LED. An easy way to test if it is the sensor
is to shine a bright flashlight onto the non-IR LED. If it shuts off it
is the sensor which can be sourced anywhere. If it doesn't shut off, it
isn't the sensor. Sensors are a major problem with Fellowes & I always
keep at least 6 sets in stock.


LEDs are emitters of light, not sensors.

MBQ

On Wed, 20 Jun 2007 08:49:21 -0700, "
wrote:

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

Shining a moderate amount of focused light on e.g. a green led gets
you way over 1 volt - enough to switch a transistor. Try it on a scope
and be amazed.

If some Chinese manufacturer can save $0.01 by using a led rather than
a light sensor - he will happily do that. There might be buying
advantages to using the exact same led for illumination and detection.

--
- René

(Peter Ashby) wrote in news:1i012q3.1a0ekg314xrqxdN%
:

Baron wrote:

Peter Ashby inscribed thus:

.....
Well practically you would be ill advised to use a generator as an
electrical motor but there is in essence no functional difference
between the two. So with a LED a current leads to light being
emitted, there is no theoretical reason why if I shine a strong
enough light of the right wavelength on a LED I won't get a current
out of it. In practical terms if I want to use my LED in this way I
will get more efficent performance if I optimise it for this
function. But this does not change the underlying reversibility of
the physics.

Peter

--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Actually I have practical experience of this phenomena !

I used an LED as a noise source, and it worked very well, but had real
problems suppressing the 50 Hz hum on the signal, until I realised
that the hum amplitude changed when I stood between it and the
fluorescent light !


Cool!

Did you rule out that you were blocking a magnetic signal?

People are not very good at acting as a magnetic shield. You need a good
conductor for an AC field and Mu Metal to block DC magnetic fields.
[or a super conductor]

My ham tranciever was sensitive to AC magnetic fields. The VCO oscillator
coil, a toroid, picked up the AC magnetic field from the tranformer in the
power supply. This made a noticable hum modulation on received and
transmitted signals. The manufacturing company has a mod kit available that
replaces the toroid with a smaller toroid that is shielded.

While I was trouble shooting the problem, I found that my soldering station,
which has a tranformer in the base, would also modulate signals.
Moving my hand in between the radio and the transformer did NOT change the
signal significantly. Therefore I doubt that the source of the ac that he was
seeing was a magnetic field. Perhaps electrostatic, but I am betting that he
found that putting a piece of black paper around the led fixed his problem.

-bz-





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

"Sam Goldwasser" wrote in message
...
Martin Pentreath writes:

On 20 Jun, 00:25, Sam Goldwasser wrote:

These sorts of sensors typically have an IRLED and photodiode. If
transmission,
they will be on opposite sides of the paper path. If by reflection, it
will be
a single sensor assembly. If you can identify the photodiode pins and
disconnect
one, that should stop the shredder if it's a sensor problem.

Can you take pics of the sensor?

Hi Sam,

I can't get a good pic of it, but it would seem that on both sides of
the paper path there is something resembling an LED, although each one
looks slightly different. There is no reflector involved so far as I
can tell.

What I would like to do is get the sensor working again. The shredder
is designed with an "on/off" switch. When the switch is set to on (and
the sensor is working properly) it is in fact in standby until
triggered by a sheet of paper detected by the sensor. With *my*
shredder on that setting the motor runs continuously. However, I can
easily stop it just by manually flicking the switch to off. I just
like having the sensor working.

First test: Try shining a bright light into the area of the sensor, or
directly if
it's apart. Even with a filter to block visible, enough should get
through and
the machine should turn off. A good flashlight might do it. I doubt it's
any more
sophisticated than simply looking for light across the paper path.

If this works, then you should be able to identify the IR LED. Then, it's
a matter
of determining if the IR LED isn't working or isn't being driven.

If the test doesn't work, the sensor may be bad.

How about the possibility of a S/C triac/welded relay contacts?

Peter Ashby inscribed thus:

Baron wrote:

Peter Ashby inscribed thus:

wrote:

On Jun 20, 3:19 pm, René wrote:
On Wed, 20 Jun 2007 04:47:04 -0700, "

wrote:
On Jun 20, 6:00 am, C wrote:
The sensor is just an IR LED. An easy way to test if it is
the sensor
is to shine a bright flashlight onto the non-IR LED. If it
shuts off it
is the sensor which can be sourced anywhere. If it doesn't
shut off, it
isn't the sensor. Sensors are a major problem with
Fellowes & I always keep at least 6 sets in stock.

LEDs are emitters of light, not sensors.

MBQ

Poor sensors perhaps, but the *do* work as sensors!

They're not used as such in any sensible application.

Well practically you would be ill advised to use a generator as
an electrical motor but there is in essence no functional
difference between the two. So with a LED a current leads to
light being emitted, there is no theoretical reason why if I
shine a strong enough light of the right wavelength on a LED I
won't get a current out of it. In practical terms if I want to
use my LED in this way I will get more efficent performance if I
optimise it for this function. But this does not change the
underlying reversibility of the physics.

Peter

--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Actually I have practical experience of this phenomena !

I used an LED as a noise source, and it worked very well, but had
real problems suppressing the 50 Hz hum on the signal, until I
realised that the hum amplitude changed when I stood between it and
the fluorescent light !

Did you rule out that you were blocking a magnetic signal?

Peter
--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Hi Peter,

Yes it was very definitely light falling on the LED. I encased the
noise source and amplifier in a tin box and that cured it
permanently. The whole thing ran from a 9 volt battery, so there
couldn't be any PSU noise.

--
Best Regards:
Baron.

bz inscribed thus:

(Peter Ashby) wrote in
news:1i012q3.1a0ekg314xrqxdN% :

Baron wrote:

Peter Ashby inscribed thus:

....
Well practically you would be ill advised to use a generator as
an electrical motor but there is in essence no functional
difference between the two. So with a LED a current leads to
light being emitted, there is no theoretical reason why if I
shine a strong enough light of the right wavelength on a LED I
won't get a current out of it. In practical terms if I want to
use my LED in this way I will get more efficent performance if I
optimise it for this function. But this does not change the
underlying reversibility of the physics.

Peter

--
Add my middle initial to email me. It has become attached to a
country www.the-brights.net

Actually I have practical experience of this phenomena !

I used an LED as a noise source, and it worked very well, but had
real problems suppressing the 50 Hz hum on the signal, until I
realised that the hum amplitude changed when I stood between it
and the fluorescent light !


Cool!

Did you rule out that you were blocking a magnetic signal?

People are not very good at acting as a magnetic shield. You need a
good conductor for an AC field and Mu Metal to block DC magnetic
fields.
[or a super conductor]

My ham tranciever was sensitive to AC magnetic fields. The VCO
oscillator coil, a toroid, picked up the AC magnetic field from the
tranformer in the power supply. This made a noticable hum modulation
on received and transmitted signals. The manufacturing company has a
mod kit available that replaces the toroid with a smaller toroid
that is shielded.

While I was trouble shooting the problem, I found that my soldering
station, which has a tranformer in the base, would also modulate
signals. Moving my hand in between the radio and the transformer did
NOT change the signal significantly. Therefore I doubt that the
source of the ac that he was seeing was a magnetic field. Perhaps
electrostatic, but I am betting that he found that putting a piece
of black paper around the led fixed his problem.

-bz-





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know
is an infinite set.

remove ch100-5 to avoid spam trap

You are right ! Actually it was a tin box, but same result !

--
Best Regards:
Baron.

Martin Pentreath schrieb:
Curiouser and curiouser - it was woking fine while the sun was shining
into my study, but it stopped working again as the light began to fade
indoors this evening. It works fine if I keep put my desklamp near it!
I guess this does mean that the IR LED is failing. Or maybe it's just
afraid of the dark, and likes to keep its motor going to scare off the
monsters.


You could use any digital camera with a CCD sensor to look at the IR
LED. The cam CCD picks up IR light and shows it as white light on the
cam screen. Try it on your TV remote while pushing one of its buttons.

Then you can check if your shredder's IR LED is working.

Sam Goldwasser writes:


They do work but rarely used in anything like this. Photodiodes are used with
IR LEDs.

But a comment in another post that it may not be the sensor also needs to be
pursued. That sensor drives a triac (probably) and they do fail shorted.

Every time I've had the issue; it was the emitter/sensor that failed;
NOT the downstream triac/relay...
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433