Isolation problems in transmitting analog signal optically

[ho83]

for isolation purposes, i need to transmit an analog signal optically, i know that there's photodiodes and phototransistors that can be connected using a fibre optic but i cant find any ..can any one give me a link to the datasheet of sush a thing ..

 

[A.Anand Srinivasan]

Re: isolation problem

it can be done using an optocoupler.....
try this link
https://category.alldatasheet.com/index.jsp?sSearchword=OPTOCOUPLER

 

[ho83]

isolation problem

i need to plcae the transmitter away form the reciever, and to connect them using a fibreoptic

 

[A.Anand Srinivasan]

Re: isolation problem

those need equipment capable of transmitting in a particular direction precisely inside the fibre..... and the receiver is compensated for a lot of nonlinearity effects.... i think it is hard to find their datasheets..... try mailing some companies.....

 

[ho83]

isolation problem

i may modulate the signal and send a digital signal (pwm for example ), so the non-linearity is not a problem... actually what i need is simply an optocoupler, but the medium that carrys the light between the trnasmitter and the receiver is a fibreoptic ...

 

[A.Anand Srinivasan]

Re: isolation problem

can you please specify what is it that you actually want.... if you could post some schematics then it would be even better....

 

[ho83]

isolation problem

ok it's simply :
i want to transmit a digital signal from a circuit to a another far located circuit witout using electrical cables .. that means i need to use a fibreoptic

 

[A.Anand Srinivasan]

Re: isolation problem

the main idea is that fibreoptic communication has not become that cheap yet and since mostly major concerns are only involved in establishing them the datasheets are not that much available so you would have to mail some companies in order to get datasheet.... i think you would be knowing the idea of transmission and receiving in fibreoptics yourself....

 

[max0412]

Re: isolation problem

Why don't you just use IR or possibly RF. IR would be the cheapest and simplest.

What is the range and is it line of sight? Are you trying to transmit a simple control signal or data?

But if your determined I've used the MFOD73 Photo detector MF0D71 Photo diode and the MFOD75 a suitable LED could be the MFOE71.I'd have to go back through my lab notes but we did several labs using those detectors and emitters for parallel/serial port communications between workstations.

Google the part numbers above,you should be able to find data sheets.

 

[hakeen]

Re: isolation problem

Hi

If you will use a distance of meters, then fiber optic Transmitter and receiver are must. In this case, simple POF (plastic over fiber) can be a comparably cheap solution. Look to HFBR-1412 and HFBR-2412 series.

If the distance should not be big so much (around 1 millimeter) or you need big distance only to isolate input-output, then use a widebody optocoupler, like HCNW136.

A last solution can be to use a IR emitter and receiver (for several decade centimeters). Then refer to, for example, HSDL-4251.

Hope it helps.

 

[angelote]

Re: isolation problem

Take a look at HFBR-0400 and similar from Agilent Techonologies.