I’m very much interested in
the 2N176 and related devices. Please provide as much info as you can. Also,
the “Motorola Power Transistor Handbook” is a real classic, and I’d like to
capture more information about this book.
As you have noted in your
discussions of Motorola power transistors the Motorola Auto Radio group had
a vested interest to have a useful power device. By 1954 the auto industry
announced it was going to switch from 6-volt batteries to a 12 volt system.
I believe all American vehicles made the switch for model year 1956. The
Motorola Two-way radio group also was interested. Both groups wanted to
eliminate the Vibrator power pack that was used to convert low voltage dc
by chopping it to low voltage ac then transforming to about 300 volts and
rectifying back to dc. Not only was this costly but the vibrator had a high
failure rate. The auto group really wanted an all transistor 12 volt radio
but this was not possible until the late 50”s. Therefore a hybrid approach
was conceived. Tungsol and other vacuum tube producers had developed a set
of low voltage tubes suitable for AM radio receivers. These tubes coupled
to a transistor power output would make a practical interim solution.
The hybrid approach would not
work for the two-way receivers since transistors were not available at the
very high frequencies that these used. The hope here was to eliminate the
vibrator with an inverter circuit using a pair of power transistors.