Re: ASRG blowing diodes

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "James Zimmerschied" <zimtesla@xxxxxxx>

Mike,
the MOV's were obtained from Radio Shack and have a number 2130LA20A 
if that helps. I believe they were rated for 1000 V. I also have a 
line filter in the box to prevent transients from entering the house 
power lines. This did not prevent the blown diodes, the MOV's seemed 
to have helped. Also the box is connected to RF ground.
Jim
----- Original Message -----
From: <mailto:tesla@xxxxxxxxxx>Tesla list
To: <mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx
Sent: Saturday, July 08, 2006 3:21 PM
Subject: Re: ASRG blowing diodes

Original poster: "MIKE HARDY" <<mailto:MHARDY@xxxxxxxxxx>MHARDY@xxxxxxxxxx>

Mike,
I have had the same problem occur. My bridge rectifier block shorted a
couple times. It is in an aluminum box next to the rotary motor. I added a
MOV from each power lead to the box which I ground. This has been successful
for some time now.
I do not have streamers hitting the power line running between the rotary
motor and my variac. You may have to put directors on your top load to steer
the arcs away from your power leads or raise the top load to direct the
streamers out.
Jim Zimmerschied
James, what value MOV's are you using on what voltage ps?I presently don't
have the metal box grounded at all. The idea of the routing of the line
could playa big factor. I have a 50 FT extension cord powering the box.-----
Original Message -----
From: "Tesla list" <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
To: <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx>
Sent: Friday, July 07, 2006 6:43 AM
Subject: ASRG blowing diodes


 > Original poster: "MIKE HARDY" <<mailto:MHARDY@xxxxxxxxxx>MHARDY@xxxxxxxxxx>
 >
 > I recently put a AR propeller gap on my 6", 4 kVA coil. It performs
 > very well, Had some 9 foot ground strikes tonight. I run a 28V, 1.5A,
 > 3600 rpm dc motor. Powered by a 6A variac into a 120 to 24 V 5A step
 > down tranny into a full bridge rectifier (20 A, 200V). This should
 > easilly run this, and it did for many hours. Varying the speed really
 > does some interesting things to the character of the streamers! I
 > decided to run the 24 line to the motor thru some flexible conduit
 > that I grounded to RF ground (in case of streamer strikes). After a
 > short time on the 4th, it poped the 2 A slowblow fuse, then stopped
 > all together. I found that half the bridge shorted, overheating the
 > tranny some. Replaced the bridge, ran it for 3 hours (not hooked to
 > the coil) at nominal line voltage, and all was fine. Ran the coil
 > again tonight, and after a few minutes it blew again! Oh by the way,
 > I didn't ground the flex conduit this time. How do others deal with
 > this, is my problem unique?
 >
 >
 >
 >