[silent:arts]

Re: Optical compression in the EU
« Reply #40 on: October 10, 2016, 04:04:01 AM »
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 ...
SSLtech: No bypass, I don't believe in it.
Gus: I think this build might have problems with DIY builders that don't know things like ohms law.


gyraf

Re: Optical compression in the EU
« Reply #41 on: October 10, 2016, 08:32:14 AM »
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.
..note to self: don't let Harman run your company..

Michael Tibes

Re: Optical compression in the EU
« Reply #42 on: October 10, 2016, 09:10:43 AM »
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

Re: Optical compression in the EU
« Reply #43 on: October 10, 2016, 12:52:13 PM »
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

Re: Optical compression in the EU
« Reply #44 on: October 10, 2016, 02:05:40 PM »
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

Re: Optical compression in the EU
« Reply #45 on: October 10, 2016, 05:51:50 PM »
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

Re: Optical compression in the EU
« Reply #46 on: October 10, 2016, 09:29:02 PM »
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

Re: Optical compression in the EU
« Reply #47 on: October 11, 2016, 02:53:19 AM »
LDRs are painted over and then calibrated by scraping off the paint.

Note to self: Keep in mind when matching T4B's
« Last Edit: October 11, 2016, 02:57:04 AM by gyraf »
..note to self: don't let Harman run your company..

benb

Re: Optical compression in the EU
« Reply #48 on: November 15, 2016, 12:33:01 AM »
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

Re: Optical compression in the EU
« Reply #49 on: November 15, 2016, 04:15:09 AM »
Make that Samsung...

Have Harman been bought by Samsung?

Cheers

Ian


[silent:arts]

Re: Optical compression in the EU
« Reply #50 on: November 15, 2016, 04:17:10 AM »
Have Harman been bought by Samsung?
yes
SSLtech: No bypass, I don't believe in it.
Gus: I think this build might have problems with DIY builders that don't know things like ohms law.

emrr

Re: Optical compression in the EU
« Reply #51 on: November 15, 2016, 09:57:46 AM »
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
« Last Edit: November 15, 2016, 11:09:38 AM by emrr »
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounded g

gyraf

Re: Optical compression in the EU
« Reply #52 on: November 16, 2016, 02:26:25 AM »
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.
..note to self: don't let Harman run your company..

Lukpio

Re: Optical compression in the EU
« Reply #53 on: March 20, 2017, 07:36:55 PM »
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...
Lukasz Piotrowski
www.amtecaudio.com

PRR

Re: Optical compression in the EU
« Reply #54 on: March 21, 2017, 12:04:46 AM »
> 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

Re: Optical compression in the EU
« Reply #55 on: March 21, 2017, 04:41:35 AM »
> 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.
Lukasz Piotrowski
www.amtecaudio.com