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July 1962 Radio-Electronics
 [Table of Contents]
Wax nostalgic about and learn from the history of early electronics.
See articles from Radio-Electronics,
published 1930-1988. All copyrights hereby acknowledged.
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 Mercury batteries used to be fairly
common in commercial and household applications. Mallory published this
full-page promotion for their line of mercury batteries in a 1962 issue of
Radio-Electronics magazine. Mercury batteries exhibit a very flat voltage
vs. time discharge curve. Mercury became a popular "public enemy" in the 1970s
when medical research exposed significant negative biological and physiological
impacts on humans. I remember in elementary school in the 1960s having the
teacher pour mercury into our hands to allow us to observe its properties. It
"exploded" into hundreds of tiny pieces when dropped on the floor ;-) Wall
switches and thermostats in homes contained mercury for making electrical
contact. I still have a couple of them for nostalgic purposes. My current oral
thermometer has mercury in it (many today use colored alcohol or kerosene). In
2008, the
Mercury Export Ban Act was enacted to "reduce the availability of elemental
(metallic) mercury in domestic and international markets." As with lead, I
believe the regulators really went overboard in reaction to the potential
danger.
Mallory - Tips for Technicians
 New Power Supply Regulates with Pulses
Distributor Division, P. R. Mallory & Co. Inc.
P. O. Box 1558,. Indianapolis 6, Indiana
The new generation of batteries
... how to use them
You may not realize it, but dry batteries used in modern electronic circuits
are as different from old style dry cells as 1962 autos are from the Model T.
Of primary interest to you as a technician is the mercury battery. Instead of
the ordinary combination of zinc, carbon, and electrolytic compounds, Mercury batteries
use mercuric oxide and a zinc amalgam in combination with an alkaline electrolyte.
This chemical system produces a dry battery uniquely matched to solid-state electronic
circuits. For example, Mercury batteries have about four times the milliampere-hour
capacity of ordinary batteries of the same physical size.
Not only do mercury batteries contain more actual power, they hold this power
for long periods of time. Ordinary batteries start to lose power from the instant
they are assembled whether used or not. On the other hand the storage life of a
mercury battery is amazing. We've had some on storage test for more than nine years
... and they're still alive.
Perhaps the best thing about mercury batteries is their steady output voltage.
It stays nearly constant throughout the entire life of the battery (see chart).
Ordinary battery voltage drops steadily. Constant voltage is important in solid
state circuits ... it means constant gain and linearity.
Terminal voltage on a mercury cell is 1.35 volts ±1/2%! This is so accurate there's
a special multi-voltage reference battery (Pt. No. 303113) that's widely used as
a secondary voltage standard. It's excellent for setting scopes, meters, etc., and
all sorts of lab work. We'll be happy to send complete information. Just ask.
Mercury batteries are a Mallory development. We like to think we're experts on
them. But we know there are jobs a mercury battery shouldn't do. Jobs where very
high surge drains or continuous heavy drains are required ... flash cameras, flashlights,
movie cameras, etc. So we developed the Mallory Manganese Battery. It's the king
of heavy drain batteries ... with excellent storage life and moderate price.
There are literally dozens of other battery systems available from Mallory. We
simply don't have space to go into them here. But if you're interested in rechargeable
batteries, or ultra low temperature types, or extreme low or high voltage types,
or other exotic types, write to Dept. 762. We'll send the information.
Meanwhile, when you need a battery for a grid bias circuit, or a portable instrument,
or a transistor radio, use a Mallory Mercury Battery. For flashlights and similar
applications use Mallory Manganese Batteries. You can get them from your Mallory
Distributor. He's the man to see for Mallory capacitors, controls, switches, semiconductors,
and vibrators ... and for all your electronic requirements.
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