HP 5245L Service Manual

A.
TOTALIZING
START- STOP SIGTAL
0tAiltJAL coilTRoL)
B.
FREQUENCY
C. PERIOD
D.
MULTI-PERIOD
AVERAGE
E.
RATIO
Section II
Paragraphs 2-41
to
2-46
Figure
2-9.
Basic
Counter Functions
2-10
Model
5245L
period.
The
decimal
point
is
positioned
to
give
the
readout
in
seconds, milliseconds
or microseconds
for
a
single
period
of
the
input
signal.
2-41.
RATIO MEASUREMENT.
As
shown
in
Figure
2-98,
the
frequency
ratio
of
two
inputs
can
be meas-
ured
bya circuit
arrangement
similar tothat used for
period
measurement.
One input
signal is
applied to
the main
gate
while the
gating
signal
is
made
equal to
the
period (or
decade
multiple of
the
period)
of the
other
signal.
The
displayed countrepresents
the
num-
ber of
cycles
of
one
inputwhich
occur during
the
period
of one
cycle
(or
decade multiple of one
cycle)
of
the
other input.
2.42.
STANDARD
FREQUENCY
OUTPUTS. Multi-
plier
and decade
divider circuits connected
to the
internal
l
MHz
oscillator
provide
output frequencies
from 10
MHz
to 0.
I Hz
(in
decade
steps)
using
the
arrangement shown
in Figure
2-10.
2-43.
SCALER OPERATION. An
input
can be
scaled
by a factor from
10 to tg9
(in
decade
steps) using
the
arrangement
shown
inFigure
z-tL.
Note that
thefirst
two
divisions are
done by the high-speed
decimal
counters
which
in
this case function
as decade dividers.
2-44.
TtfilE SEQUENCE.
2'45.
GENERAL. Folloving
a counter measurement
there
are several
operations which
occur
in
a
partic'
ular
sequence.
The
pulses
which
control
these
oper-
ations and
their time
relation to
each
other are shovrn
in
Figure
2-L2.
The
trailing
edge
of
the
gating
pulse
(end
of
count
)
triggers the
one-shot multivibrators
(Paragraph
2-19)
which
generate
these
pulses.
2-46.
TRANSFER.
The
transfer multivibrator is
triggered at
the
end of the
gating
signal,
and it
pro-
duces
a
35-millisecond
pulse.
The
transfer
pulse
is
applied
to the decimal
counters
to transfer
the
new
count
to the
display.
During a measurement
function
the count is stored in
the
storage binaries until the
transfer
pulse
allorvs the new count
to
be displayed.
Figure
2-L0.
Standard
Frequency Outputs
02349-1
o5243-A-rI
O!ea
5-
3- lO

HP 5245L Specifications

General

Brand	HP
Model	5245L
Category	Cash Counter
Language	English