Ac - Led Button; Dc - Led Button; Lf - Led Button; Tv - Led Button - Hameg HM400 Handbuch

POWER
F u n c t i o n o f t h e c o n t r o l s
18 19
VOLTS / DIV VOLTS / DIV
.2 .2
.1
.5 50 .5
3
VAR
20
1 1
10
2 2
5 5 5
10 2 10
5
1
20 20
V mV V
6
DC
DC
AC GND AC
CH 1
X-INP INPUTS
1 MΩ II 15 pF
max.
400 V
p
!
CAT I
29 36 30 31
32
„External trigger source" means that the trigger signal is
not taken from the measuring signals but from an exter-
nal source.
25 STOP AC – LED button
In all operating modes of the vertical amplifi er except XY pressing this
button shortly will select AC trigger coupling which will be indicated
by the LED lighting up.
26 DC – LED button
In all operating modes of the vertical amplifi er except XY pressing this
button shortly will select DC trigger coupling which will be indicated by
the LED lighting up. The peak-to-peak detection will be disabled.
27
LF – LED button
In all operating modes of the vertical amplifi er except XY pressing this
button will insert a low pass fi lter (see the specifi cations) into the trigger
path which will be indicated by the LED lighting up. The low pass will
suppress high frequency interference which could disturb triggering.
28 TV – LED button
In all operating modes of the vertical amplifi er except XY pressing
this button shortly will activate the TV trigger separator which will be
indicated by the LED lighting up. The following remarks apply to the
PAL TV standard.
For frame synchronization the TIME/DIV (20) knob should be set between
0.2 s/DIV and 1 ms/DIV, at 2 ms/DIV a full frame will be displayed.
For line sycnhronization the TIME/DIV (20) knob should be set between
0.5 ms/DIV and 0,1 us/DIV. At 10 μs/DIV single lines can be displayed,
about 1 ½ lines will be visible.
29 DC/AC – LED button for CH 1
By pressing this button shortly, the coupling of channel 1 can be alter-
nated between DC and AC, the LED will light up if AC is selected.
30 GND – LED button for CH 1
By pressing this button shortly, the input of the channel 1 preamplifi er
will be connected to ground which will be indicated by the LED lighting
up, the signal present at the input BNC connector can not infl uence
the trace. If automatic triggering was selected, there will be a bright
baseline, the position of which depends only on the CH 1 position
control. If normal triggering was selected, the trace will only be
visible if there is a suffi cient trigger signal available from the trigger
source selected and the TRIGGER LEVEL
that start pulses for the time base generator are produced – this will
be apparent by the TRIG'd LED
position of the input is used for setting the trace to a desired position
before the signal is applied.
42 Subject to change without notice
23 21 25 27
22
24 26 28
TIME / DIV
.2 .1
.1
TRIGGER
ms .5
50
1
20 CH 1 AC
2
10
5
CH 2 DC
10
5
20
2
LINE LF
50
1
.1s
mV
.2s .1
EXT TV
HOLD
OFF
GND INV ON
CH 2 EXT. TRIG / Z-INP
PROBE ADJUST
1 kHz / 1 MHz
ca. 0.2 Vpp
39
37 38 40
33 34
14 control was adjusted so
15 lighting up. In practice, the GND
20
31 DC/AC – LED button for CH 2
By pressing this button shortly, the coupling of channel 2 can be alter-
nated between DC and AC, the LED will light up if AC is selected.
50
VAR
20
10
30 GND – LED button for CH 2
5
By pressing this button shortly, the input of the channel 2 preamplifi er
2
will be connected to ground which will be indicated by the LED lighting
1
up, the signal present at the input BNC connector can not infl uence the
.5
µs
.2
trace. If automatic triggering was selected, there will be a bright base-
line, the position of which depends only on the CH 1 position control. If
Z-INP
normal triggering was selected, the trace will only be visible if there is a
suffi cient trigger signal available from the trigger source selected and
the TRIGGER LEVEL
1 MΩ II
15 pF
max.
time base generator are produced – this will be apparent by the TRIG'd
100 V
p
LED 15 lighting up. In practice, the GND position of the input is used for
setting the trace to a desired position before the signal is applied.
33 INV – LED button for CH 2
35
By pressing this button shortly, the display of the channel 2 signal can
be alternated between normal and inverted. The LED will light up if
inversion is selected.
34 HOLD-OFF/ON – LED button
By shortly pressing this button, adjustment of the hold-off time by
turning the knob /TIME/DIV
by the LED lighting up. See also under
triple function of this knob. The knob allows an increase of the hold-off
time from its minimum value by turning it CW, if the end of the range
is reached, an acoustic signal will be heard. Also, when the knob is
turned CCW, the acoustic signal will sound when the minimum value is
reached. As soon as the hold-off time adjustment is disabled by again
pressing 34 , the hold-toff ime will be automatically reset to its minimum
value. By shortly pressing the TIME/DIV knob while
is possible to alternate between setting the time/div. and hold-off time
adjustment. See also under „Hold-off time adjustment".
35 Z-INP – LED button
By shortly pressing this button, the function of the input EXT.TRIG/Z-
40
INP is changed from external trigger input to external intensity
modulation input which will be indicated by the LED lighting up. If ex-
ternal triggering or the „Component Tester" are selected, no intensity
modulation will be possible resp. it will be disabled. 0 V at the input will
not change the trace intensity, with 5 V TTL level the trace will be fully
suppressed, higher voltages are not allowed.
36 INPUT CH 1 – BNC connector
This is the CH 1 input in YT mode and the X input in XY mode. The ground
of this connector is connected to the chassis and thus to the mains safety
earth. The buttons DC/AC
37
INPUT CH 2 – BNC connector
This is the CH 2 input in Yt mode and the Y input in XY mode. The
ground of this connector is connected to the chassis and thus to the
mains safety earth. The buttons DC/AC
to this input.
38 PROBE ADJUST – Contact
At this contact a square wave signal of 1 kHz or 1 MHz with a rise time
<
of 5 ns and an output impedance of 50 ohms is available for the ad-
justment of probes other than 1:1, the amplitude is appr. 0.2 Vpp. For
probe adjustment purposes neither the frequency, nor the duty cycle
nor the exact amplitude are of concern.
The frequency of the square wave depends on the setting of the TIME/
DIV 14 selector: between 0.2 s/DIV and 100 μs/DIV the frequency will
be 1 kHz and between 50 μs/DIV to 100 ns/DIV it will be 1 MHz. See the
chapter „First time operation and initial settings and „Probe adjustment
and application."
39 PROBE ADJUST – Contact
This is the ground connection for the probe.
14 control was adjusted so that start pulses for the
14 will be activated which will be indicated
14 for information about the
34
29 and GND 30 belong to this input.
31 , GND 32 and INV
is activated, it
33 belong