B: RE: Intermittent Tach & power outlet question

[BobsV35B at aol.com]

Good Morning Michael,
 
The correct answer is that It All Depends!
 
If you will provide your serial number, John Collins could probably tell  you 
what it was when it left the factory, but many have been modified so that is  
not a sure bet.
 
Some Barons were equipped with a standard twelve volt cigar lighter. Beech  
installed a resistor in series with that outlet that had about the same  
resistance as the cigar lighter.  If you check the no load voltage with a  volt 
meter, it will show the full twenty-eight (or twenty-four if the alternator  is 
not running) volts, but the resistor will drop the voltage appropriately  when 
it is loaded with the stock cigar lighter.
 
Unfortunately, many folks tried to use the cigar lighter outlet for other  
purposes and since the resistor was not likely to be sized to accommodate the  
new load, the voltages were not what was expected. The later airplanes use a  
special (read for a truck) cigar lighter and there is no resistor in the  
circuit. It is my understanding that many folks have removed the dropping  resistor 
and not made a notice to that effect in the ship's papers.
 
I think it would be pertinent to do a little sleuthing with Volt/Ohmmeter  to 
find out just how your individual outlet is wired.
 
Check the size of the wire and the circuit protection to see how much  
current can be safely carried by that circuit.
 
In any case, if the circuit is still wired as it came from the factory,  
there should be no potential for a fire!
 
Happy  Skies,

Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West  86th Street
Downers Grove, IL 60516
630 985-8502 
Stearman  N3977A
Brookeridge Air Park LL22



 
In a message dated 2/27/2008 9:49:57 A.M. Central Standard Time,  
mitchell at policetrust.com writes:

1979  Beech Baron B55 IO470

Intermittent Tach, we have experienced varying  degrees of Tach issues. The
mechanics have cleaned and secured the "cannon  plugs" which offered
temporary relief. At this point the left seems to  function at 99%, while the
right does not come alive until run  up.

Power outlet, does anyone know what the voltage is for the DC  outlets are in
the Baron? Additionally, what type of sustained load will  these outlets
take. I'm wanting to hook up a small inverter to run a laptop  on a 3-4 hour
flight. Any concerns about load (fire) ect.

Thanks in  advance for the responses.

Michael Mitchell
www.971v.com    






**************Ideas to please picky eaters. Watch video on AOL Living.      
(http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/
2050827?NCID=aolcmp00300000002598)