<VV> Christmas Lights

[Arjay Morgan]

  I guess I didn't express the Christmas lights scheme clearly enough, so here's another try:
   
  The power source is a fully charged 12 volt battery separate from the Corvair electrical system. It's nestled in the well of the luggage compartment in its own battery box. No attachment to the car's alternator.
   
  Attached to it is a homebuilt inverter using a pair of TO-25 transistors on a huge heat sink. It puts out a square wave waveform @ 110 volts and will allow a current draw of about 500 watts. 
   
  The chaser lights don't give a fig about the square waves. only rotating armature devices care. 
   
  The inverter is inefficient....it draws about two amps to create about a half amp of AC. Yes, the battery will run down, but since it's a separate battery  the only downside is that I'll haul a dead battery home. There are no circuit breakers in this system, just brute force. I know better than to ask it to deliver more current than it's designed for and the best load tester is a hand on the heat sink
   
  I'm sure the 110 VAC output could be dangerous to an old man with a bad heart standing in a puddle of salt water with a wire in each hand, but I was taught practical electricity by Harry Thomas who always checked if a light socket was 'live' by sticking his finger into it. Yes, you get a shock, but the electricity only flows from the tip of your finger to about the second phalange, not across your chest.
   
  The system has been tested --- clip inverter to battery, plug in lights, flip switch, watch chaser lights --- chase.
   
  You could probably do the same thing with a store-bought inverter, but it would cost a lot more and be plagued with circuit breakers because the average bozo who buy 'em figures he can just plug in his sump pump and worry no more.
   
  hope that explains what is a decent, simple, kluge it is.
   
  Arjay
   
   
   
  Message: 6
Date: Thu, 30 Nov 2006 18:13:00 EST
From: JVHRoberts at aol.com
Subject: Re:  Christmas Lights
To: vairologist at verizon.net, virtualvairs at corvair.org
Message-ID: 
Content-Type: text/plain; charset="US-ASCII"

 
There's yet another problem with the transformeroffthealternator 
approach.  
Frequency. Automotive alternators are WAY higher than 60Hz, and most 
standard  
transformers have way too much impedance at those frequencies. 
There are some decent cheap inverters with close to sine wave output 
these  
days...
 
 
In a message dated 11/30/2006 1:07:30 P.M. Eastern Standard Time,  
vairologist at verizon.net writes:

Beginning Saturday and continuing for cruise nights up until Christmas  
we 
have a set of manic chaser christmas lights. There is a spare battery 
in  the 
trunk and humongously powerful inverter I built years ago when power  
transistors were the size of quarters. Those items will be in the 
trunk,  powering the 
chaser lights which will be strung all the way 'round the  beltline of 
the car. 
a fullsize, stuffed, santa claus will be in the driver's  seat. We 
figure it 
should annoy most everyone within 100 feet and there will  be joy all 
about.
Arjay Morgan
------------------------------------------------------------
Smitty  Says:  Arjay, for several years our club took part in the 
Parade of  
lights in Norfolk.  (before the greenies decided they didn't like  
cars).  
Anyway we were required to light our cars which we attempted to  do 
using 
commercial inverters.  Two problems with that.  One was  that it didn't 
take many 
lights to pop the Circuit breakers on even the larger  inverters and 
they would 
rapidly drag the battery down unless you could  maintain a pretty high 
rpm.  
Another problem was that the square wave  from the inverter doesn't 
allow the 
chase lights to work.  One of our  members hit on the idea of using the 
12 volts 
from one phase of the alternator  before it is rectified and boosting 
it 
backwards through a 110/12 volt  transformer to get the required 110 
volts AC.  
The cars regulator keeps  the voltage stable and the chase lights work 
fine.  
One time Walter  Carter from our club tapped into all three phases of 
the 
alternator and using  three transformers, put over a thousand lights on
his car.  A couple  of notes of caution here.  This voltage developed 
is like 
house  current.  Treat it with respect.  Another thing.  It takes a  
pretty 
hairy transformer to do the job.  Door bell  transformers  aren't even 
close to 
meeting requirements.




 
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