Home |
Search |
Today's Posts |
#12
posted to rec.boats.electronics
|
|||
|
|||
Varistor to shield voltage spikes
Thanks Ken, useful info. Your remark about the isolation transformer (which I have installed) as well as your url. Regards, Len. On Sun, 15 Jan 2006 09:24:30 -0700, Keith Hughes wrote: Len, MOV's will help protect you from *large* spikes (like spikes from lighting hitting the grid nearby, large transformers arcing, etc.) but will not do anything for surges, sags, or common mode problems typically seen from poor generation. For that, you need something like a UPS, or a ferroresonant transformer backed by MOV's for major-spike protection. If you use a varistor with a sufficiently low clamping voltage to protect you from surges, you'll fry it pretty quick. Varistors protect by providing a short circuit at high voltages, and if that short lasts very long...poof. Using a ferro as an isolation transformer will isolate you from the generation plant, provide transient protection, carry you through voltage sags (depending on duration of course), and dampen surges. The biggest downside is that they are inefficient, especially under light loads, and that translates into heat. They are also fairly intolerant of frequency variation. The link below has all the info about varistors you could want: http://www.littelfuse.com/data/Appli...tes/an9767.pdf Keith Hughes |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
alternator, voltage regulator question | Cruising |