Optical compression in the EU

[[silent:arts]]

Just looking at another thread reminded me that all the street lights in the UK use something similar to an ORP12 cadmium sulphide light sensor. What are they going to replace all those with?

Just call it public safety and you have the same exception the police or military have.
And trains and airplanes ...

 

[gyraf]

Yes, but for all measure-the-light applications, Si-based photodiode/transistor works just as well. In audio, we're really alone in having this problem...


Jakob E.

 

[Michael Tibes]

I'm preparing to file an application for exemption - I may very well need cross-EU support for the cause...

Jakob E.

If there's anything I can do t support things from Germany let me know.

Michael

 

[PRR]

Streetlights can use Silicon phototransistors. Linearity of light response or signal passthrough is not an issue. The large CdS cell does allow circuit simplicity, but these days that is not an issue. There is probably already a chip with the eye in one end and an SCR on the other, a 2-leg solution.

I was startled looking at (US market) oil-burning house furnaces. There's apparently just 3 models (in more brands) and the diagnostics talks of "Cad cell" for flame detection. Gas furnaces have switched to an ionization wire for flame check (also a full microcomputer instead of thermal relays). As a "Cad cell" is a replaceable item, how are they managing the wide values of cells sold in this uncertain market? (Or have they switched to a Silicon thingie which replaces a CAD and not bothered to change the documentation?)

 

[benb]

Just looking at another thread reminded me that all the street lights in the UK use something similar to an ORP12 cadmium sulphide light sensor. What are they going to replace all those with?

Cheers

Ian

Probably a photodiode or phototransistor that costs about 10 cents more. These cadmium-whatever sensors are real inconsistent from unit to unit, but there's a really big difference in light between daylight and night, which in this application only means some street lights will come on a few minutes before others.

The Magic Dust in these Vactrols/LDR devices isn't that they're optically sensitive (and selected for consistent sensitivity and response time), it's that they have this particular on-off response timing that just happens to work well and sound good in a compressor.

 

[ruffrecords]

Probably a photodiode or phototransistor that costs about 10 cents more. These cadmium-whatever sensors are real inconsistent from unit to unit, but there's a really big difference in light between daylight and night, which in this application only means some street lights will come on a few minutes before others.

I mentioned them because I know they use CdS cells. They all work the same way. LDR in series with a heating element that heats a bi-metallic strip and opens a contact to shut off the light during daylight. At night the LDR turns off the heater, the bi-metal bends and the light comes on/ They even try to arrange the heat from the light reaching the sensor at night to be the same as from the bi-metal heater during the day to counteract temperature sensitivity of the LDR. I went round the UK factory where they are made back in the 80s. LDRs are painted over and then calibrated by scraping off the paint. The same basic system is still in use all over the world.

Cheers

ian

 

[Gene Pink]

Just call it public safety and you have the same exception the police or military have.
And trains and airplanes ...

Hmmm.

Protecting human hearing from loud transients using comp/limiters, sounds like a public safety issue to me.
;D

Gene

 

[gyraf]

LDRs are painted over and then calibrated by scraping off the paint.

Note to self: Keep in mind when matching T4B's

 

[benb]

You could always inform your local standards body that Harman is possibly importing products that violate ROHS. Should be fun!

Cheers

Ian

Make that Samsung...

 

[ruffrecords]

Make that Samsung...

Have Harman been bought by Samsung?

Cheers

Ian

 

[[silent:arts]]

Have Harman been bought by Samsung?

yes

 

[emrr]

Yes, Fender vibrato opto's are out as well...

I see Fender replacements are still available here in the US, is that just residual stock?

I'm hearing these are being used:

http://www.digikey.com/en/product-highlight/a/advanced-photonix/cds-photocells

 

[gyraf]

Yes, some of the LDR cells are still manufactured and available (but sadly not the Exelitas/Vactec couplers).

But available does not mean that you are allowed to include them in anything that has a CE/WEEE-marking.

Rationale for still allowing sales of the part itself is repair of old units. Like the 60/40 lead solder you can still get everywhere.

Jakob E.

 

[Lukpio]

Jacob, what if... selling an "opto" compressor with no cell installed, but with a socket for it, and including a free CdS opto cell. The user could easily install it and voila. No rules are broken. Just a thought...

 

[PRR]

> what if... selling an "opto" compressor with no cell installed, but with a socket for it, and including a free CdS opto cell. ...No rules are broken.

What if... selling an opium pipe with no opium in it, and including a free hit of opium. The user could easily install it and voila. No rules are broken?

I do not know if CdS is subject to the same stringent laws as opium is in many countries. But it seems unlikely to pass muster with a judge.

 

[Lukpio]

> what if... selling an "opto" compressor with no cell installed, but with a socket for it, and including a free CdS opto cell. ...No rules are broken.

What if... selling an opium pipe with no opium in it, and including a free hit of opium. The user could easily install it and voila. No rules are broken?

I do not know if CdS is subject to the same stringent laws as opium is in many countries. But it seems unlikely to pass muster with a judge.

CdS cells, lead solder etc is still being sold legally in the EU. What is illegal is selling new gear that contains it inside the product.

 

[12afael]

I know it is an old topic, I just notice that ampeg released an opto compressor and it is at thomann ???

https://www.thomann.de/gb/ampeg_opto_comp.htm

 

[gyraf]

Same (European) place sells WA-2A/KT-2A/VT-737/ART/Comp3A/Voxbox/ ISA430/TwinQ/M103/ and so forth, as well as numerous guitar pedals based on same technology.

..as mentioned earlier - industry is desperately trying to ignore the problem away...  : 

Jakob E.

 

[warpie]

Anarchy in EU!  ;D

 

[pucho812]

does the EU really check for this, or is it an honor system? the EU assumes you are doing it?