Opto Isolators

[3guk]

Guys I have heard many people taking about using these in a DMX chain to stop kit from being ruined due to spikes.

 

 

rom what I understand they are some sort of LED and a reader the LED flashes and the reader converts this back into data and carries on down the line eliminating spikes.

 

Is this right ?

 

Where do I need to put the optoisolators after every light ??

 

Cheers

[Jivemaster]

On a mains powered install you shouldnt need one unless you need the Repeater aspect to cope with long leads or too many devices on a wire, or the Splitter aspect to send DMX two or more ways.

 

On a multi generator rig where there may be multiple earth potentials then there can be currents in the DMX shields and over potentials in common mode at the data pins causing failure. So a isolating repeater becomes a necessity.

[robloxley]

Generally these aren't stand-alone items but are found within bits of DMX kit - e.g. in splitters to isolate outputs from each other and the input, and in many desks to stop a fault damaging the desk.

[sam.henderson]

Martin make one (which knowing them is probably over-priced) along with loads of other compnaies. If you plan on using over 32 devices on a line, you want to split the line and send it two ways (Y-Spliters won't work) or you have a cable run of over aprox. 500m then you will need one.

 

As mentioned you will also need one "On a multi generator rig".

 

Sam