Newbie Questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jtf-at-dejazzd-dot-com>

Struck my first spark last night. Yippe! Little 1/4 inch spark from a 555 
driving a HEI
coil. Similar to:
http://www.geocities-dot-com/CapeCanaveral/Lab/5322/coildrv.gif
Now for some questions:

1.) The current meter on the 12 Vdc power supply didn't move. Heat sink on 
the NPN
transistor didn't get warm. Curious to know the current draw in the primary 
circuit.
DMM gave a null reading across a 0.03 ohm sense resistor in the emitter 
leg. Using a
50mVolt analog meter movement, calculated the current to be 0.83 Amps. Why 
did the
DMM give a null reading? Too high a frequency, plus a square wave, for the 
meter? I
would have assumed that without a current limiting resistor, the primary of 
the HEI coil
would have drawn more current. The calculated 0.83 Amps was an "average", 
would
the inrush current be higher: in the order of several amps? The circuit 
diagram
indicates 6 Amp supply. Why the disparity?

2.) Next step is to double the supply voltage to 24 Vdc ( two gel cells in 
series). Does
the base biasing resistor, for the NPN transistor, need to change with a 
higher supply
voltage? The goal is to increase the supply voltage to the coil primary, 
and hopefully
get a higher secondary spark. Each time I increase the primary supply 
voltage, will the
base bias resistor need to change?

Thanks in advance. These are elementary questions for this list.

John