Clairex Photocell Application Handbook, Vactrols and Silonex

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Clairex Photocell Application Handbook, Vactrols and Silonex

Post by mediatechnology » Sun Sep 04, 2011 7:15 pm

"Photoconductive Cell Application Design Handbook," Clairex Electronics, 1978. ... lairex.pdf (Full Handbook, Color, 26.4 MB)

This file is huge and takes awhile to render once downloaded. I had to scan it in color since Clairex chose to print black on dark blue. The CL505 is not in this pdf but the CL5M5, which appears to be a CL505 in a different package, is.

I found a copy of an earlier 1971 catalog before Clairex discontinued the glass-cased CL500-series units.

CL500-series, CL505 datasheet: ... 5_1971.pdf

It's always amazed me why people use RED LEDs (think LA-4 Vactrol) with type 5 photocells to make compressor/limiters. Green/yellow (think LA-3 EL) hits the typical CdS cell closer to it's spectral peak; Red is off from 40-70%. If I were going to build an opto-compressor I might use a green/yellow LED.

Here's a handy LED chart:

Vactrols are now made by Excelitas:

The datasheets for the VTL-series require you to drill through about 30 pages of datasheet listings. These are the direct links:

Excelitas Vactrol VTCL5C1 and VTL5C2 Data:
Excelitas Vactrol VTCL5C3 and VTL5C4 Data:
Excelitas Vactrol VTCL5C4/2 Dual Data:

Silonex's website has an "under construction page" where there used to be datasheets. I found this link to some datasheets:

Silonex is still available from Allied.
The NSL-5910 is often used in LA-3 clones: ... KU=6990100

Silonex NSL-series data is here: ... ocells.pdf

Hopefully there are still enough Industrial, Scientific and Medical markets to justify photocell and Vactrol production despite RoHs restrictions. The consumer market for photocells is now officially dead. Epoxied into a Vactrol, how's that Cadmium going to get out? When photocells are outlawed, only outlaws are going to have photocells, opto compressors, opto-phasers, vibrato and other "criminal" devices.

Updated link to Vactrols: ... 767&p=8956

Covidland (The Movie) Part 1: Lockdown

A voice-over with Orson Welles: "What Is It That You Want?": ... u_Want.mp3
Americas Frontline Doctors Lawsuit Motion For Preliminary Injunction Of Covid-19 Vaccine Emergency Use Authorization: ... zation.pdf

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