[ARC5] Vibrator Power Supplies

[J. Forster]

I have a Sencore PR570 which has a Variac(R) equivalent and V, I, and W
metering. I'll run up an unloaded Radio Shack transformer in the next day
or so and plot up the data. That'll measure the core loss and saturation
voltage at 60 Hz.

Best,

-John

==================



>
> On Dec 7, 2012, at 8:50 PM, Geoff wrote:...
>> A lot of the old gear transformers are already starting saturation
>> at 123 and are toast at 130. The use of bucking transformers to get
>> down to 110-113 is very popular and the heat reduction is dramatic.
>
> Geoff,
>
> Thanks for your experience in the power supplies.  I often suggest
> bucking transformers and sometimes note that you can run the primary
> of it from either the line, or the reduced, bucked, output voltage.  I
> had not realized that an older transformer from the junque boxe might
> not do well running on the higher voltage line.
>
> Experiment request to the group:
>
> Find a recent Radio Shack small filament transformer  Run it at modern
> line voltage and load it with a resistive load at or very near the
> rating of the thing.  Look at the load voltage with a scope and see
> how hot it gets in free air after an hour of running.  I've read that
> they operate well into saturation with squared off voltage peaks, and
> get quite hot.  This implies that the designers cut the iron used
> below a happy amount,  and are counting on modern materials and
> insulation to keep it running at least past the warrantee period. (IS
> there a warrantee?  Maybe not.)
>
> A search at http://www.radioshack.com
> returns NO hits for "filament transformer" but does list some
> candidates for "transformer".
> They don't believe in filaments any more!
> The 12 volt offerings are:
>
>   Model: 273-1352  |  Catalog #: 273-1352
>
> 12.6V CT 1.2A Standard Center Tap Transformer with leadsPrice:$10.49
>
> Model: 273-1511  |  Catalog #: 273-1511
>
> 12.6V CT 3.0A Chassis-Mount Transformer with Leads
>
>   Model: 273-1365  |  Catalog #: 273-1365
>
> RadioShack® 12V CT 450mA Std Chassis-Mount Xformer w/ LeadsPrice:$7.49
>
>
> Model: 273-1385  |  Catalog #: 273-1385
>
> 12.6V 300mA PCB-Mount Miniature TransformerPrice:$4.99
>
>
>
> By the way this item:
>
> RadioShack® Audio Output Transformer
> Model: EI-19  | Catalog #: 273-1380
>
> Claims 1000 ohms primary, 8 ohms secondary and 300 to 10 khz
> response.  Might do for command set use.  Price is $2.99  No power
> level given.
>
> Roy
>
> Roy Morgan
> k1lky at earthlink.net
> K1LKY Since 1958 - Keep 'em Glowing!
>
>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>