Growler transformer....

[mrcaptainbob]

I was looking at a manual a couple days ago where there was a picture describing how to check armature coils. Place the armature over an open core transformer (growler) and hold a hacksaw blade slightly above the top side of the armature. If it was good it would flutter or vibrate. So.....what is an open core transformer? What type of machine/appliance are they normally used in? And...what kind of word is 'growler'? Is that a brand name or a type of transformer?

[paul52446m]

I was looking at a manual a couple days ago where there was a picture describing how to check armature coils. Place the armature over an open core transformer (growler) and hold a hacksaw blade slightly above the top side of the armature. If it was good it would flutter or vibrate. So.....what is an open core transformer? What type of machine/appliance are they normally used in? And...what kind of word is 'growler'? Is that a brand name or a type of transformer?

As always DuneMe, you are not even close
Blue Point MT-326B Armature Growler Tester for sale

growler tester - Yahoo! Search Results
I haven't used one in 30 years, but here they are. Paul

[HayZee518]

DuneMe - go back to school.
A growler was used back in the days of automotive DC generators and auto starters. it is used to locate shorted armature slots and bars. the open armature of this transformer sets up a magnetic field in it. an armature set into the V shaped iron punchings completes the magnetic field and induces a voltage into the rotor. a hacksaw is normally used to verify that the coils of the rotor are not open. when passed over the copper armature a spark would mean the coil is good, no spark, the winding is open.

[Speedbump]

Man, you guys are taking me back to the days where as a kid, Hanging around the auto parts store.

[paul52446m]

Man, you guys are taking me back to the days where as a kid, Hanging around the auto parts store.

Makes you feel old? I can remember when i had a growler on my bench, when i was running a gas station in the 1960. That was a while ago. Paul

[mrcaptainbob]

Growler....

WOW! Well, I guess the book that was shown to me was pretty old! A friend had a difficult time finding what was wrong with his old truck starter, pulled out this book and asked me about it. I never heard of it, so thought it was technique that I somehow missed learning about. Hmmm, so now it's on to either finding a large, open pole transformer, old finding a different (more modern??) way of checking that armature. Can a vom do it?

[HayZee518]

you can use a vom but its tedious. each winding that is connected to each copper bar on the end of the armature is "rung out" with the meter. one probe goes to the iron, the other probe goes to each bar on the commutator. when you find the shorted bar [winding] the meter will go full scale.

[mrcaptainbob]

Growler motor....

Thanks guys for the help.....will experiment....