Electronic Fuse; Connecting The Load; Fig. 4.1: Compensating The Voltage Drops In Diagram - Hameg HM8143 Benutzerhandbuch

mit selected I will be reached. At this moment the in-
max
strument will change from constant voltage regulation to
constant current regula-tion. Any further load increase will
cause the current to remain stable while the voltage U
decreases ultimately to zero.
3 .5

Electronic fuse

In order to provide a better protection than current limiting,
the HM8143 features an electronic fuse. As soon as Imax
is reached all outputs will immediately be disabled (Out-
put LED is off). They may be turned on again by depres-
sing OUPUT.
4 Connecting the
load
out
The load has to be connected to the middle safety termi-
Compensation of the voltage drop across the cables
nals. For the connection please use 4 mm banana plugs.
Power source
Sense error
amplifier
source
variable

Fig. 4.1: Compensating the voltage drops in diagram

The transparent terminals are the SENSE inputs. With
these SENSE terminals the voltage loss across the cables
can be compensated. The HM8143 balances this voltage
loss automatically and the load will see the voltage set.
Connect two separate measurement cables in parallel to
the connecting cables of the load.
Please note the polarity of the load terminals: the red terminal is
the positive, the black terminal is the negative connector.
Example:
If you want to connect low loads please notice that the
„not used" power is transformed into heat. If you set 4 V x
2 A = 8 W at the 32V channels, the rest of the instrument
power of 26 V x 2 A = 52 W (per channel) will be trans-
formed into heat (= 104 W). This is a typically behaviour
of a linear regulated power supply. In this case, the heat
can not be transported out of the HM8143 chassis con-
tinuously. Based on this the instrument shuts down the
channels to protect the internal circuitry. For connecting
low loads we recommend using a switching power sup-
ply (e.g. HMP series). A switching power supply is crea-
ting heat for the used power only, not for the „not used"
power.
For continuously usage of low loads a switching power supply is
recommended. The bigger the load, the more suitable a linear re-
gulated power supply.

Connecting the load

cable
+ Sense Pick-Up
+ Source
cable
– Source
– Sense Pick-Up
load
27