Surge Protector - how they work?

Hi,

it is the thunder season here in Finland so I got interested how these surge protectors are built - which say they will save you hardware from spikes - yeah....

Are there avalanche diodes and coils?

I have a dim feeling I have asked this before...

Best Regards Kari

--
PIC - ARM - Microcontrollers - I2C - SPI
Keypads - USB-RS232 - USB-I2C - Accessories
http://www.byvac.com
I am just a happy customer
Reply to
Kari Laine
Loading thread data ...

A voltage-dependent resistor, usually.

Reply to
Nobody

Lo

High voltage causes a MOV (metal oxide varistor) to close. Both the input and output points become the same voltage, preventing current flow through the circuit.

--





















> 
> Are there avalanche diodes and coils? 
> 
> I have a dim feeling I have asked this before... 
> 
> 
> Best Regards Kari 
> 
>
Reply to
John Doe

You have a season? It's pretty much year round in Florida.

--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
Reply to
Michael A. Terrell

"John Dope Head "

** More absolute BOLLOCKS from this congenital moron.

Piss this TROLL off !!!!

.... Phil

Reply to
Phil Allison

A common surge protection device is a Voltage-Dependent Resistor (VDR), also called a Metal Oxide Varistor (MOV) or simply a varistor. It acts rather like two zener diodes back to back. It's placed across the power line and does nothing when the voltage is within normal limits, passing only a small leakage current. When the line voltage exceeds a certain limit, the varistor breaks down and acts as a shunt. It can absorb large amounts of energy from momentary spikes, but when the high voltage is sustained, the varistor breaks down permanently. It may burn up or even explode. Even then, it may have done a useful job by blowing a fuse.

However, it's a good idea to keep in mind that few, if any, protection schemes are 100% foolproof. For more details, you may want to read up on MOVs/VDRs on the net.

Reply to
pimpom

Regular, very active, nym-shifting

"Phil Allis> Path:

news.astraweb.com!border1.newsrouter.astraweb.com!nntp.club.cc.cmu.edu!feeder.erje.net!goblin2!goblin3!goblin.stu.neva.ru!exi-transit.telstra.net!pit-in1.telstra.net!news.telstra.net!news-south.connect.com.au!not-for-mail

2010 03:58:54 GMT)
Reply to
John Doe

"John Dope Head the Moron "

** More absolute BOLLOCKS from a blatant congenital moron.

Piss this DAMN TROLL right off !!!!

.... Phil

Reply to
Phil Allison

Kari Laine expressed precisely :

Adding to pimpom. You asked what was in those devices. You will have to open up one from your locale. Here in California, we have Radio Shack stores around the corner and my friend an I were trying to do something similar so we went to Radio Shack and opened one up. Inside we found the MOV and a toroid. The toroid may have been wound a a balun or simply as an inductor. We did not want to cut into it to see. This also helps reduces spikes coming in. In our case we were trying to stops spikes going out of an appliance so we added some 500V ceramic caps (essentially high frequency filters across the line) to further reduce that noise spectrum that might interfere with X10 devices we have plugged in around the house. We are in test phase now.

Reply to
BeeJ

balun?? probably as a common-mode choke (both windings in parallel)

You should use X capacitors for cross-line applications

--- news://freenews.netfront.net/ - complaints: snipped-for-privacy@netfront.net ---

Reply to
Jasen Betts

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.