How to test a bridge rectifier?

[TSC]

I have a DMM, and thought I knew how to test a bridge rectifier. All game
actions point to it being bad, but my DMM testing shows it as good.

So, to put this item to rest, what is the CORRECT way to test the bridge
rectifier? What setting on the DMM, and which posts do I test with the
red/black probes? Test with machine on or off?

For the cost of a bridge rectifier I will likely just replace it, but I
would like to learn how to do it correctly!

[Lloyd Olson]

There are four diodes in there, end to end ( two banded ends tied together,
two non banded ends tied together ). Set your DMM on diode setting, check
all the legs around one direction, then reverse the leads and check them all
the way around again. Between any two legs if it's open or dead short, you
have a problem. Between any two if way different then the others you have a
problem. This may not show up a flaky BR, just a bad one. LTG :)

"TSC" <fakea...@dontspamme.com> wrote in message
news:LEGpf.41728$XC4....@twister.nyroc.rr.com...

[beaver]

- Put DVM on diode setting
- DVM red to bridge '-'.
- Verify conduction to both AC terminals.
- DVM black to bridge '+'
- Verify conduction to both AC terminals.
- DVM black to bridge '-'.
- Verify open to both AC terminals.
- DVM red to bridge '+'
- Verify open to both AC terminals.

Edward Cheung

[Pin Geek]

You are right about replacing them though. If these are the original bridge
recs, they are ready to go sooner or later anyway.

--
Josh
http://www.pingeek.com
Get your pinball show dvds here:
http://host300.ipowerweb.com/~pingeekc/dvd_sale.htm
See you at Allentown Pinball Wizards Convention 2006
Order last year's show here:
http://host300.ipowerweb.com/~pingeekc/atown2005_dvd.htm

"TSC" <fakea...@dontspamme.com> wrote in message
news:LEGpf.41728$XC4....@twister.nyroc.rr.com...

[Pint...@gmail.com]

Everything here is the correct shotgun test proceedure. Unfortunately,
the best way is to load test one. It's usually not done because one,
they are fairly inexpensive, and two, once it's out of the game your
halfway there, plus you need a load bank and a storage scope.

These bridges are rated at 35amps, (in most cases), so you need to load
test based on the manufacturers spec sheet. (We used 75% for one
hour).

A bridge can test fine on the bench, but under load one of the four
components may "leak", which in our test lab was called "clipping".
This lowers the output voltage to the regulator. Sometimes the
clipping is random, or intermittant. This can stress the regulator and
cause it to fail. It can be just load dependent.

In short, replace them.

Mario
Pinthetic

[chi...@charter.net]

On at least two occasions, I've had bridges test good via the methods
outlined here, that ended up being bad. They are cheap. Ditto Mario.
Replace them.

BTW...straight from one of Clays guides at:
http://www.marvin3m.com/sys80/index1.htm#power

Testing a Bridge Rectifier.
To test a bridge rectifier, do this:

Put the DMM on diode setting.
Put the black lead of the DMM on the "+" (positive) terminal of the
bridge.
Put the red lead of the DMM on either AC bridge terminal. Between .4
and .6 volts should be seen. Switch the red DMM lead to the other AC
bridge terminal, and again .4 to .6 volts should be seen.
Put the red lead of the DMM on the "-" (negative) terminal of the
bridge.
Put the black lead of the DMM on either AC bridge terminal. Between .4
and .6 volts should be seen. Switch the black DMM lead to the other AC
bridge terminal, and again .4 to .6 volts should be seen.
--
Chris Hibler

[Pin Geek]

years ago, like in the 80's, I heard bridge recs used to cost over $10 or
some ridiculous figure like that. This was pre.........historic.......I
mean eh, pre internet. I was in high school.

--
Josh
http://www.pingeek.com
Get your pinball show dvds here:
http://host300.ipowerweb.com/~pingeekc/dvd_sale.htm
See you at Allentown Pinball Wizards Convention 2006
Order last year's show here:
http://host300.ipowerweb.com/~pingeekc/atown2005_dvd.htm

<chi...@charter.net> wrote in message
news:1135050085.1...@g44g2000cwa.googlegroups.com...

[brightn...@gmail.com]

DVM is a multimeter?

[John Robertson]

On 2017/09/06 5:19 AM, brightn...@gmail.com wrote:
> DVM is a multimeter?
>

Yes.

John ;-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."