Evening public ledger. [volume] (Philadelphia [Pa.]) 1914-1942, 1922-05-20
The Best Way to Handle a "B" Battery
by HENRY NJ NEI

Visit ten amateurs and "sit in at
their receiving sets and it is safe bet
that nine of them will have their "B"
batteries chuCked on the table any old
place. They will have loose wires lying
,bout them or will have one wire con-
nected to the set and the other with a
hose end with which they experiment
,llv touch the various posts of the bat
,sry while they listen in and will then
screw the wire to that post.
"It's good enough they will tell
,ou And it undoubtedly does work all
,vII ,,,obt but It is a lot of trouble. COM
nsred 10 the way they might have IL
arranged. and it looks Sloppy on a
table. -,
YOUR "B' battery in the unit sys-
fem of construction we have been ad-
vocating in these articles. It saves
heap of trouble in operating and it gives
that neat and workmanlikc appearance
10 the set that brings added JOY to its
Il is as we'll at the very start of your
career as n radio enthusiast to buy a
l5.yolt "B" battery. Then you are
ready to face any kind Of audion bulb
that you buy or tha, your friends bring
around for you to try on your set.
The handiest kind of battery of this
strength has a wire permanently fixed
20 the "plus' side. Half the block is
sold and the other half has binding
POSTS coming up through the insulating
substance, and these posts have millcd-
headed nuts on them to screw down over
ne wires and hold them tight.
There are fifteen Of these binding
POSTS on the minus side and another
permanent wire imbedded in the insu-
iatng substance. These two permanent
wires. the plus and the minus. give the
full 45.vot strength of the battery.
The fifteen binding posts give various
strengths, in steps OF IA volts each,
from 22Is volts to 45.
For this panel, as for the rest of this
unit system. you want a 6-by -G-inch
board for the base and G-by -8-inch
piece Of formica or bakelte or n GOOD
piece Of dogwood for the panel.
Two binding posts are set about an
Inch apart low down in the center
Of the panel. These are the plus and
minus posts and the strength of current
that comes from them to your bulb will
depend entirely upon where the switch
blade above them is set.
There are seventeen contact points in
the circle around which this switch
blade revolvcs. The battery has fifteen
minus binding posts and the last per-
manent wire on the minus side. which
makes sixteen ''taps" that you can
take off your battery. But you want
one more contact point in the circle to
cut out the current entirely. This con-
tact point, of course, is not connected to
anything. 1t "opens" the circuit and
stops the flow of electricity.
The "plus' wire or binding post on
the battery block is connected directly
70 the plus binding post OH the panel.
The minus binding post on the panel Is
connected directly to the shaft of the
switch blade
Then each binding post on the battery
block is wired to one Of the switch con-
net points on the panel. The point
against which the switch blade is rest
ing In the illustration is the 'out'
point; the battery is "open rircuitcd"
and no current can be taken from it.
The next point connects Mt once to
the 221a volt post OH the battery. 1t
INT necessary to have anything less
tnan 22!a volts because all tubes need
thls much at least. Then, in turn. each
succeeding post on the battery block
connected by wire to the next con.
uct point on the circle and the final
wire, embedded in the block on the
minus Side, goes to the last contact
point.
with this connected up. you have a
unit that is complete, readily adjusta.
ole, easily handled, and that looks neat
.na workmanlike. 1t is we'll worth the
uouoie to make because it saves a lot Of
tfouole in operating the set.
''9vn0hf. 1872. BY Public Ledger paav