ORP12 etc Cd-S LDR and the RoHS directive.

I

Ian Field

Guest
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio Spares
catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs that
activate a sound effect when someone walks past - its not difficult to see
that the sensor is a LDR. It has a CE sticker on it, but no mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet) changing
hands at collectables prices.

Thanks for any help.
 
On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.
Click to expand...

Why do you care? Audio companders or something like that? I do a lot
of analogue stuff, but haven't used a CdS cell since probably 1978.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
 
"Phil Hobbs" wrote in message news:5410D819.2020802@electrooptical.net...

On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.

Why do you care? Audio companders or something like that? I do a lot of
analogue stuff, but haven't used a CdS cell since probably 1978.

Cheers
Click to expand...

They are still very widely used as daylight sensors in PIR sensors and
lighting photocells. I saw some recently in a CE marked, UK produced sensor
where the CdS LDRs had been 'trimmed' in production by scraping off some
black paint covering the active area. We use 'light to digital' sensors in
our higher end sensors.

JB
 
"JB" <nil@spam.net> wrote in message news:lusfa5$lii$1@dont-email.me...
"Phil Hobbs" wrote in message news:5410D819.2020802@electrooptical.net...

On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.

Why do you care? Audio companders or something like that? I do a lot of
analogue stuff, but haven't used a CdS cell since probably 1978.

Cheers

They are still very widely used as daylight sensors in PIR sensors and
lighting photocells. I saw some recently in a CE marked, UK produced
sensor where the CdS LDRs had been 'trimmed' in production by scraping off
some black paint covering the active area. We use 'light to digital'
sensors in our higher end sensors.
Click to expand...

When contractors installed fire alarms and emergency lighting in the flats,
I rescued a few light fittings from the outdoor utility lighting that had
daylight shut off.

A couple had mains voltage LDRs driving a hotwire/bimetal relay, a couple
more had silicon photodiodes - near as I could tell; similar to BPW34. The
photodiode drives an op-amp buffer/comparator - its a proven circuit for
sensing daylight with a silicon photodiode, but an LDR still wins hands down
for spot on daylight response.
 
"Phil Hobbs" <hobbs@electrooptical.net> wrote in message
news:5410D819.2020802@electrooptical.net...
On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.

Why do you care? Audio companders or something like that? I do a lot of
analogue stuff, but haven't used a CdS cell since probably 1978.
Click to expand...

You never know - I might want to submit a magazine project that uses them,
that might get a bit tricky if the supply dries up and they start changing
hands at collectibles prices.
 
On 9/11/2014 11:32 AM, JB wrote:
"Phil Hobbs" wrote in message news:5410D819.2020802@electrooptical.net...

On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.

Why do you care? Audio companders or something like that? I do a lot
of analogue stuff, but haven't used a CdS cell since probably 1978.

Cheers

They are still very widely used as daylight sensors in PIR sensors and
lighting photocells. I saw some recently in a CE marked, UK produced
sensor where the CdS LDRs had been 'trimmed' in production by scraping
off some black paint covering the active area. We use 'light to digital'
sensors in our higher end sensors.

JB
Click to expand...

They're complete crap if you actually want to measure anything,
though--their resistance can vary as much as 5:1 based only on previous
history.

A far better way to make a wide-range photometer is to measure the open
circuit voltage of a photodiode, and temperature-compensate the result.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
 
"Phil Hobbs" <pcdhSpamMeSenseless@electrooptical.net> wrote in message
news:5412509D.5050707@electrooptical.net...
On 9/11/2014 11:32 AM, JB wrote:


"Phil Hobbs" wrote in message
news:5410D819.2020802@electrooptical.net...

On 9/10/2014 3:39 PM, Ian Field wrote:
Seems like I can't get a definitive answer from Google as to whether
Cadmium-Sulphide light dependant resistors are RoHS exempt or not.

Someone on another forum thinks they may have seen a note on a Radio
Spares catalogue that LDRs aren't compliant.

Recently I saw on sale in one of the Ł1 stores; novelty plastic frogs
that activate a sound effect when someone walks past - its not difficult
to see that the sensor is a LDR. It has a CE sticker on it, but no
mention of RoHS.

For now, I've ordered a small stash from Ebay as they aren't (yet)
changing hands at collectables prices.

Thanks for any help.

Why do you care? Audio companders or something like that? I do a lot
of analogue stuff, but haven't used a CdS cell since probably 1978.

Cheers

They are still very widely used as daylight sensors in PIR sensors and
lighting photocells. I saw some recently in a CE marked, UK produced
sensor where the CdS LDRs had been 'trimmed' in production by scraping
off some black paint covering the active area. We use 'light to digital'
sensors in our higher end sensors.

JB


They're complete crap if you actually want to measure anything,
though--their resistance can vary as much as 5:1 based only on previous
history.
Click to expand...

They're perfect for those plastic frogs that emit a novelty sound effect
when anyone walks past and casts a shadow on the sensor.
 
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