Not necessarily... the bathtub curve applies, it is much more likely for
brand new electronics to fail than those that have been run for years. If
the factory didn't give it a burn in period it could be a spontaneous part
failure. Or it could be miswiring internally that didn't show up in
whatever short test they may have given it. A diode failure in a bridge
could put AC on the regulator, or a capacitor that isn't soldered properly
could be passing half wave dc and over stressing it, connect the wrong wires
to or from the transformer to the board and you could blow lots of things
after a short time, etc.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://wiki.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://k1ttt.net
-----Original Message-----
From: David Jordan [mailto:wa3gin@comcast.net]
Sent: Friday, June 01, 2012 14:14
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Or2800DC smoking control box
Nat sent me a picture of the inside of the controller. It appears one of
the DC voltage components near the rear panel is fried, maybe a regulator.
Black soot on the board and melted plastic sprayed on the inside of the rear
panel. The question in my mind is what externally could be faulted such
that this device would self-distruct with such violence. Having just come
for the M2 factory one would conclude the fault was external to the
controller.
73,
Dave
wa3gin
----- Original Message -----
From: "Zivney, Terry" <00tlzivney@bsu.edu>
To: <towertalk@contesting.com>
Sent: Friday, June 01, 2012 9:36 AM
Subject: Re: [TowerTalk] Or2800DC smoking control box
> Les, W2LK said:
>
> The OR2800DC runs on 30-47VDC. Polarity determines rotation direction
> and voltage determines speed.
> If the control box is smoking, there is probably a stray wire strand
> shorted in the control cable somewhere.
> I would think that the likelihood of a short in the rotator itself is low.
> Pins 1 & 2 on the rear of the controller are the turning voltage.
> Pins 5 & 6 are around 10V, low current, used for the pulse counter and
> shouldn't be a problem.
> Recheck the controller cable connections for stray strands or cracks/cuts.
> Les W2LK
>
> **************
>
> A DC motor should turn (slowly) on well under the rated operating
> voltage.
>
> A short in the 'control wire' will not cause smoking. The reed switch
> in the rotor SHORTS terminals 5 & 6 in normal operation; shorting
> and opening those terminals is how the control box determines
> the location of the antenna (counting pulses).
>
> Terry N4TZ
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
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