Question about order changers

Started by Redvers, August 30, 2017, 07:35:29 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Redvers

Does anybody know how commercial switchers achieve this? I mean, I know how I'd do it, using dpdt relays, but for 4+ loops that would be a lot of relays. Is there a chip or something they use nowadays?

admin

#1
Relays are the most transparent and have the least distortion, but can suffer "pops" on transitions.

A CPU  managed zero crossing detector circuit manages switching the relays with the least DC offset.

Google "Analog Mux IC, then review the images reveals the IC circuits available today
There used to be several ICs available from NJR (JRC) that provided many switching options  - but most have gone  EOL ( End of Life) not recommended for new designs 
http://pdf1.alldatasheet.com/datasheet-pdf/view/7603/NJRC/NJU7313AL.html

or for government and Rad Hard ( = $$$)
http://html.alldatasheet.com/html-pdf/49684/AEROFLEX/ACT8505/647/2/ACT8505.html

http://www.njr.com/semicon/audio_video/index.html
http://www.njr.com/semicon/audio_video/audio_switch.php?cat=3400


Its appealing but be mindful  of the limited voltage swing of the signal being switched must within the range of the IC's power rails 

Today many units (MS-3) employ A/D on every input and D/A on every output , and perform the switching "swizzle" re- rerouting within a DSP or FPGA

Redvers

Thanks for the reply! So is this the kind of thing the boss loop switchers would employ?

admin

#3
The ES-5, ES-8 use relays

The MS-3 uses A/D and DSP and D/A

Read the manuals as those block diagrams provide incite