Simpson 1000 - Push Buttons

THEORY OF OPERATION
Plate voltages used for diode tests are the same as the
grid bias voltages listed above for positions of toggle K,
and a 24,000 ohm resistor is placed in series with the tube
circuit as a current limiting resistor.
L SWITCH
Toggle switch.L is a single section switch which selects
a shunt value to place across the meter movement as a
course sensitivity adjustment. This switch uses all six
positions (0 through 5) marked on the panel. The positions
marked 0, 1, 2, 3 and 4 furnish a variety of sensitivities
such that high current tubes will use the zero position and
low current tubes will use the #4 position of this L switch.
The £5 position of the L switch connects the bias voltage
from the K switch through the 24,000 ohm resistor to be
used as plate voltage for light duty diode tests.
PUSH BUTTONS
There is a group of fourteen push-switches located in a
row above the toggle switches. The red push button at the
left hand side is labelled “RELEASE”, and is used to re-
store all the black push buttons to their up position at the
end of a tube test.
Buttons A through J transfer the connections of the tube
elements for short testing and for the value test. A me-
chanical catch system under the push button switches is
arranged so push switches A through J release when any
other switch in the same group (A through J) is pressed.
During the short tests, each element is checked separately
when one of this group of push buttons is pressed. When
the second element is tested, the push button for the first
32