W
Watson A.Name - Watt Sun
- Jan 1, 1970
- 0
I removed both of the 470 uF 200V 'lytics from an old SMPS, and I
found these two devices, one across each of the 'lytic caps. I
thought at first that they were ceramic caps, but each was covered
with a piece of heat shrink tubing, and that got me puzzled. So I cut
off the HST and I read the designation on it: TVR07221. So I did a
web search and came up with this.
http://www.millipex.com/cptj/xqymdz/psd/Varistor-12.pdf
You can see from the specs that each of these is only good for a
quarter watt. What puzzles me is why they would be across the caps
with 160VDC on them all the time. It seems to me that the more
sensible place to put these is upstream, before the bridge rectifier,
so that they can protect both that and the stuff downstream. Weird,
huh.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
found these two devices, one across each of the 'lytic caps. I
thought at first that they were ceramic caps, but each was covered
with a piece of heat shrink tubing, and that got me puzzled. So I cut
off the HST and I read the designation on it: TVR07221. So I did a
web search and came up with this.
http://www.millipex.com/cptj/xqymdz/psd/Varistor-12.pdf
You can see from the specs that each of these is only good for a
quarter watt. What puzzles me is why they would be across the caps
with 160VDC on them all the time. It seems to me that the more
sensible place to put these is upstream, before the bridge rectifier,
so that they can protect both that and the stuff downstream. Weird,
huh.
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
