TM 11-6625-444-14-1
5-8. Display
b. The polarity signs + and - of tube V1 are
controlled by a flip-flop consisting of transistors
Q19, Q20, FET switches Q32, Q33, current source
a. The display (A14) circuits control the
transistors Q9, Q10, and associated components.
function/status indicators and the decimal in-
Inputs to this circuit are VDC, C POL INFO A
dicators associated with the readout tubes. The
and B and a. POL INFO A and B come from the
polarity detector in the A/D converter and
indicators are controlled by the respective func-
determine which of the two polarity characters are
tion control lines. They are illuminated when +5
illuminated. The range counter, through a,
volts dc is applied to the control line; however,
reverses the effects of POL INFO A and B as a
the control lines are interlocked in the associated
function of range to account for the fact that the
assembly so that the indicator remains ex -
polarity detector receives the input to the in-
tinguished unless the assembly is installed. The
strument in its true sense on the l-volt range, but
overrange indicator is operated by transistor Q5
in its inverted sense on all other ranges.
in the overrange driver circuit.
