FET optocoupler as VR - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 23rd September 2006, 02:59 PM   #1
Leolabs is offline Leolabs  Malaysia
diyAudio Member
Leolabs's Avatar
Join Date: Dec 2004
Location: Bukit Mertajam
Send a message via MSN to Leolabs
Question FET optocoupler as VR

I already read the thread about the Silonex's Audiohm optocoupler "Lightspeed Attenuator",wondering how about Fairchilds's H11F1???Although the Ron is higher,about 200 ohms.
  Reply With Quote
Old 24th September 2006, 05:38 AM   #2
EUVL is offline EUVL  Europe
diyAudio Member
Join Date: Oct 2003
You get poor linearity for any input signal more than +/- 0.02V (see Figure 2 Output Characteristics of Datasheet).

  Reply With Quote
Old 24th September 2006, 07:48 AM   #3
diyAudio Member
Join Date: May 2004
Location: Hertfordshire
Poor linearity is another way of saying distortion
Thanks for the heads up on the lightspeed attenuator thread
Those devices are sometimes known as vactrols and used by record producers to get the sound they like using compression, an ugly word for hi-fi enthusiasts. In fact the compressor is also called a joemeek after the legendary record producer who first used the technique.
Until I discovered the Silonex parts (perkin-elmer stuff is difficult to get in the UK) I made my own devices using a yellow Led (to match the wavelength of the LDR) a LDR and some 5mm heatshrink sleeve.
In the Lightspeed attenuator the device is simply used as a volume control there is no compression.
Another way of doing it is here:
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Can I replace transformer drive with optocoupler in halfbridge smps? lakone Power Supplies 1 11th May 2009 02:20 PM
Analog amp with optocoupler lumanauw Solid State 2 12th August 2008 02:36 AM
HCPL3100 Optocoupler Gold_xyz Parts 1 18th November 2006 06:38 PM
optocoupler to eliminate ground loop ostie01 Solid State 26 27th March 2006 08:29 AM
high speed optocoupler djdamix Class D 5 21st April 2005 02:54 PM

New To Site? Need Help?

All times are GMT. The time now is 01:33 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2