View Single Post
  #3   Report Post  
Posted to sci.electronics.repair
Steve[_15_] Steve[_15_] is offline
external usenet poster
 
Posts: 35
Default Hastings VT-4B Replacement Transformer

On 17 Dec 2007 19:03:11 -0500, Sam Goldwasser
wrote:

sck0006 writes:

We have a Hastings VT-4B made by Beede Electronic Instruments Co,
Inc. The line transformer in this unit has burned. It's a custom
transformer, made by Regional Mfg. Specialists, part number 528214-G.
From what I can tell, it just feeds into a bridge, center tap
grounded, which powers the LM78L12 & L79L12 regulators. Dimentions on
it are 1.635in x 1.325in x 1.325in. It has wire leads, no terminals,
and is mounted by two screws through the cores. Any suggestions for
replacement? Would a 12.6-0-12.6 transformer give enough headroom for
the regulators?


The electroncs draw very little power so it might be OK. 12.6 * 1.4 (peak) is
about 17.6 V, But, you need 1.4 V or so for the bridge, another 2? V for the
regulator, and something for ripple, so that's getting close to the required
12 VDC output, especially over the allowed line voltage range.

I'd probably go with 14 VRMS or so if there is a standard part you can fit
in there.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.


Thanks for the reply Sam, always apprecaited. The only thing I could
find with the right dimensions in a hurry was a Hammond 266C24. I
guess we'll just wait unitl it gets here and see. I believe I'm going
to have to rip off the chassis mount part and drill through the cores,
but maybe I'll get a little lucky.

Thanks again,
Steve