HP AC-4A User Manual

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AC-4A IN BASIC COUNTER CIRCUIT
Fig 2 is a schematic circuit of the counter in Fig. 1. The Amp-
litude Discriminator can be built following the circuit in Fig. 3
(Schematic Diagram Amplitude Discriminator Unit for Model
522A/B )_ This Amplitude Discriminator is available from Hewlett-
Packard Company as a plug-in unit -hp- Part No. 522B -58B. The
GATE is a manually operated switch but could be a pair of relay
contacts . Counters are RESET to zero with a manual pushbutton.
The power supply should be able to furnish +300 volts at 15 ma and
6. 3v ac at 1. 2 amps for each AC-4A used, in addition to +2 l0v
regulated at 10 ma, -10 5v regulated at 3 ma, and 6. 3v at . 6 amp
for the Amplitude Discriminator.
This counter will count at a maximum rate of 120 kc or more and
the total number of digits displayed is limited only by the number
of AC -4A
I
s used.
To adjust Rl2:
a. Connect a 1000 cps sine wave to the input of the
Amplitude Discriminator (Fig. 2).
b. Observe the output at Pin 1 with a scope or ob-
serve the AC-4A Counters for steady operation.
c. Decrease amplitude of 1000 cps input.
d. Adjust Rl2 for a symmetrical square wave or for
steady operation of the AC -4A Counters.
e. Repeat above steps until the minimum input voltage
is reached.
f. This is the correct setting of the sensitivity control
for best operation at all input voltages and frequen-
cies.
-4-

HP AC-4A Specifications

General

Brand	HP
Model	AC-4A
Category	Cash Counter
Language	English