paul@voder.UUCP (07/09/86)
Can MOV's really be protected with fuses? Some of the recent chatter in
this group seems to indicate that this is the case. Are there fuses which
are fast enough to protect (or at least indicate bad) MOV's? If this is
true, why isn't somebody making a mint selling a single package MOV/fuse?
--- phd {nsc!voder!paul}
If God had meant penguins to fly, he would have given them wings.hsu@eneevax.UUCP (Dave Hsu) (07/10/86)
In article <1380@voder.UUCP> paul@voder.UUCP (Paul Dietz) writes: >Can MOV's really be protected with fuses? >--- phd {nsc!voder!paul} Fuses operate thermally, and the metal alloys used take a while to heat up enough to melt (or at least become elastic). The duty cycle of the pulses that MOVs clamp are generally very low. Fuses will conduct large pulse currents without much heating. I suppose you could connect multiple varistors in parallel with small value current equalizing resistors in series with each varistor (one per MOV). But why bother? Varistor protects, wears out, shorts, fuse blows, equipment off. What more could anyone ask for? Varistors are insurance that's soooo inexpensive. -- --==---==---==-- [this is a borrowed account; please send correspondence to:] .. the vorpal blade went snicker-snack! .. ARPA: don@umd5.UMD.EDU BITNET: don%umd5@umd2 UUCP: ..!{ seismo!umcp-cs, ihnp4!rlgvax }!cvl!umd5!don (NOTE: Please mail to umcp-cs!cvl!umd5!don NOT umd5!cvl!umcp-cs!don) ( Please be SURE your mailer has ^ the correct address. Thanks. )
dennisg@sdcrdcf.UUCP (07/18/86)
>Varistor protects, wears out, shorts, fuse blows, equipment off. >What more could anyone ask for? >Varistors are insurance that's soooo inexpensive. But what about when they fail OPEN? Sometimes your varistor protection goes avay with no dramatic explosion or blown fuse to let you know. Yes, I use them anyway.