Why an Optocoupler is needed in Offline Power Supplies?

[chanchg]

Optocoupler

What and why an Optocoupler is needed in Offline Power Supplies?

Thanks

 

[pvinbox@yahoo.com]

Re: Optocoupler

hai

for electrical isolation between two different voltages
optocouplers are used
famous optocouplers are MCT2E, 4N35

 

[chanchg]

Re: Optocoupler

hai

for electrical isolation between two different voltages
optocouplers are used
famous optocouplers are MCT2E, 4N35

What do you mean by Electrical isolation between two voltages? Can you please clarify?

 

[Kaleem]

Re: Optocoupler

It means there is no flow of electrical signal between the two rather the electrical signal is converted into light signal which travels between the two.

 

[truebs]

Re: Optocoupler

I'd like to elaborate.

Once i used optocouple when i coupled the input from my circuit as a output to parallel port of my computer.

As computer is a sensitive issue, just few milliampere current more or few volts more can lead to complete mother board failure or other failures.

Hence the need of electrical isolation.
In an optocoupler the maximum current is limited by the intensisty of light. Hence better and safer.

Refer to Optical Communication by John M Senoir for more details on optocouplers and their applications.

 

[masoudk_81]

Re: Optocoupler

Hi

in switching power supply, in one side you have 220 (or 110) volts and in the other side, you have another voltage that can be lower or higher, if you don't isolate one side from the other, you may get shocke whan you touch one of your output wires and it will be so dangerous. optocoupler makes an optic coupling between two sides and prevents this. in some applications, you need outputs that are isolated and have differnet grounds. it's another purpose.

masoud

 

[mark_nctu]

Re: Optocoupler

Yes, it just isolates high voltage and low voltage power system and
pretects low voltage device.