Hameg HM7042-5 User manual

HM7042-5
Triple Power Supply
User Manual

General remarks regarding the CE marking
HAMEG measuring instruments comply with the EMI
norms. Our tests for conformity are based upon the
relevant norms. Whenever different maximum limits are
optional HAMEG will select the most stringent ones. As
regards emissions class 1B limits for small business will be
applied. As regards susceptability the limits for industrial
environments will be applied. All connecting cables will
inuence emissions as well as susceptaility consideraly.
The cables used will differ substantially depending on
the application. During practical operation the following
guidelines should be absolutely observed in order to
minimize EMI:
1. Data connections
Measuring instruments may only be connected to external
associated equipment (printers, computers etc.) by using
well shielded cables. Unless shorter lengths are prescribed
a maximum length of 3 m must not be exceeded for all data
interconnections (input, output, signals, control). In case an
instrument interface would allow connecting several cables
only one may be connected. In general, data connections
should be made using double-shielded cables. For IEEE-bus
purposes the double screened cable HZ72 from is suitable.
2. Signal connections
In general, all connections between a measuring instrument
and the device under test should be made as short as
possible. Unless a shorter length is prescribed a maximum
length of 3 m must not be exceeded, also, such connections
must not leave the premises. All signal connections must be
shielded (e.g. coax such as RG58/U). With signal generators
double-shielded cables are mandatory. It is especially
important to establish good ground connections.
3. External inuences
In the vicinity of strong magnetic or/and electric elds
even a careful measuring set-up may not e sufcient
to guard against the intrusion of undesired signals. This
will not cause destruction or malfunction of HAMEG
instruments, however, small deviations from the guaranteed
specications may occur under such conditions.
General remarks regarding the CE marking
DECLARATION OF CONFORMITY
Manufacturer:
HAMEG Instruments GmbH
Industriestraße 6 · D-63533 Mainhausen
The HAMEG Instruments GmbH herewith declares conformity of the
product:
Product name: Triple Power Supply
Type: HM7042-5
complies with the provisions of the Directive of the Council of the
European Union on the approximation of the laws of the Member
States
relating to electrical equipment for use within dened voltage limits
(2006/95/EC) [LVD]
relating to electromagnetic compatibility (2004/108/EC) [EMCD]
relating to restriction of the use of hazardous substances in
electrical and electronic equipment (2011/65/EC) [RoHS].
Conformity with LVD and EMCD is proven by compliance with the
following standards:
EN 61010-1: 04/2015
EN 61326-1: 07/2013
EN 55011: 11/2014
EN 61000-3-2: 03/2015
EN 61000-3-3: 03/2014
EN 61000-4-2: 12/2009
EN 61000-4-3: 04/2011
EN 61000-4-4: 04/2013
EN 61000-4-5: 03/2015
EN 61000-4-6: 08/2014
EN 61000-4-11: 02/2005
EN 61000-6-3: 11/2012
For the assessment of electromagnetic compatibility, the limits of
radio interference for Class B equipment as well as the immunity to
interference for operation in industry have been used as a basis.
Date: 8.6.2015
Signature:
Holger Asmussen
General Manager
北京海洋兴业科技股份有限公司（证券代码：839145）
www.hyxyyq.com

General remarks regarding the CE marking
Content
Table of content
General remarks regarding the CE marking 16
Technical Data 18
1 Important hints 20
1.1 Symbols 20
1.2 Unpacking 20
1.3 Positioning 20
1.4 Transport / Storage 20
1.5 Safety instructions 20
1.6 Proper operating conditions 20
1.7 Warranty and Repair 21
1.8 Maintenance 21
1.9 Mains voltage and Changing the line fuse 21
2 Operating Controls 22
3 Basics of Power Supplies 23
3.1 Linear power supplies 23
3.2 Switched-mode Power Supplies (SMPS) 23
3.3 Parallel and Series Operation 23
3.4 Current Limit 24
3.5 Electronic Fuse 24
4 Concept of the HM7042-5 25
4.1 Output power of the HM7042-5 25
4.2 Switching the display on/off 25
5 Introduction to the operation 25
5.1 First time operation 25
5.2 Turning on the HM7042-5 25
6 Operating controls and displays 26
6.1 Kanal I + III 26
6.2 Kanal II 26
6.3 Current Limiting 27
6.4 Electronic Fuse 27
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HM7042-5
Technical Data
Key facts
2 x 0…32V/0…2A 1 x 0…5.5V/0…5A
High-performance and inexpensive laboratory power supply
Floating, overload and short-circuit proof outputs
Separate voltage and current displays for each output
4 digits at channel 1+3; 3 digits at channel 2
Display resolution:
10mV/1mA at channel 1+3; 10mV/10mA at channel 2
Protection of sensitive loads by current limit or electronic fuse
Pushbutton to activate /deactivate all outputs
Low residual ripple, high output power, excellent regulation
Parallel (up to 9A) and series (up to 69.5V) operation
Temperature-controlled fan
PD 5210.8608.32 - 02.01
HM7042-5
Triple Power Supply
Technical Data
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HM7042-5
Technical Data
Technical Data
Accessories supplied:
Operating manual, line cord
Recommended accessories:
HZ10S 5 x silicone test lead (black)
HZ10R 5 x silicone test lead (red)
HZ10B 5 x silicone test lead (blue)
HZ42 19" Rackmount Kit 2RU
Triple Power Supply
HM7042-5
All data valid at 23°C after 30 minutes warm-up.
Outputs
2 x 0…32V/2A and
0..5,5V/5A
ON/OFF pushbutton control, SMPS
followed by a linear regulator, floating
outputs for parallel/serial operation,
current limit and electronic fuse
Output 1+3 (32V)
Range: 2 x 0…32V, continuously adjustable 2
knobs (coarse/fine)
Ripple: ≤100µVEff (3Hz....300kHz) typ.,
≤1mV (10Hz...1MHz)
Current: max. 2A
Current limit/electronic fuse: 0…2A, continuously adjustable (knob)
Recovery time (10…90% load
variation):
80 µs within ±1 mV of nominal value
30 µs within ±10 mV of nominal value
0 µs within ±100 mV of nominal value
Max. transient deviation: typ. 75mV
Recovery time (50% basic load,
10% load variation):
30 µs within ±1 mV of nominal value
5 µs within ±10 mV of nominal value
0 µs within ±100 mV of nominal value
Max. transient deviation: typ. 17mV
Display:
7-Segment LED: 32,00V (4 Digit)/2,000A (4 Digit)
Resolution: 0,01V/1mA
Display accuracy: ±3 digit voltage / ±4 digit current
LED: indicates current limit
Output 2 (5,5V)
Range: 0…5.5V, continuously adjustable (knobs)
Ripple: ≤100µVEff (3Hz....300kHz) typ.,
≤1mV (10Hz...1MHz)
Current: max. 5A
Current limit/electronic fuse: 0…5A, continuously adjustable (knob)
Recovery time (10…90% load
variation):
80 µs within ±1 mV of nominal value
10 µs within ±100 mV of nominal value
Max. transient deviation: typ. 170mV
Recovery time (50% basic load,
10% load variation):
30 µs within ±1 mV of nominal value
15 µs within ±10 mV of nominal value
0 µs within ±100 mV of nominal valuee
Max. transient deviation: typ. 60mV
Display:
7-Segment LED 5,50V (3 Digit)/5,00A (3 Digit)
Resolution: 0,01V/10 mA
Display accuracy: ±3 digit voltage/±1 digit current
LED indicates current limit
Maximum ratings
Max. voltage applicable to output terminals:
CH 1 + CH 3 33V
CH 2 6V
Reverse voltage: max. 0,4V
Reverse current: max. 5A
Voltage to earth: max. 150 V
Miscellaneous
Safety class: Safety class I (EN61010-1)
Mains supply: 115 V/230 V ±10 %; 50…60 Hz, CAT II
Mains Fuse: 115V: 2 x 5A; slow blow 5 x 20mm
230V: 2 x 2,5A; slow blow 5 x 20mm
Power consumption: max. 330VA/250 W
Operating temperature: +5…+40°C
Storage temperature: -20…+70°C
Rel. humidity: 5…80% (non condensing)
Dimensions (W x H x D): 285 x 75 x 365mm
Weight: approx. 7,4 kg
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1 Important hints
(1) (2) (3)
1.1 Symbols
Symbol 1: Caution, general danger zone –
Refer to product documentation
Symbol 2: Risk of electric shock
Symbol 3: Ground
1.2 Unpacking
Please check for completeness of parts while unpacking.
Also check for any mechanical damage or loose parts. In
case of transport damage inform the supplier immediately
and do not operate the instrument.
1.3 Positioning
Two positions are possible: According to picture 1 the front
feet are used to lift the instrument so its front points slightly
upward (approx. 10 degrees). If the feet are not used (picture
2) the instrument can be combined with many other HAMEG
instruments. In case several instruments are stacked (picture
3) the feet rest in the recesses of the instrument below so
the instruments can not be inadvertently moved. Please do
not stack more than three instruments. A higher stack will
become unstable, also heat dissipation may be impaired.
1.4 Transport / Storage
Please keep the carton in case the instrument may require
later shipment for repair. Losses and damages during
transport as a result of improper packaging are excluded
from warranty!
picture 3
picture 2
picture 1
Dry indoors storage is required. After exposure to extreme
temperatures 2 h should held off on turning the instrument
on.
1.5 Safety instructions
The instrument conforms to VDE 0411/1 safety standards
applicable to measuring instruments and left the factory
in proper condition according to this standard. Hence it
conforms also to the European standard EN 61010-1 resp.
to the international standard IEC 61010-1. Please observe
all warnings in this manual in order to preserve safety and
guarantee operation without any danger to the operator.
According to safety class 1 requirements all parts of the
housing and the chassis are connected to the safety ground
terminal of the power connector. For safety reasons the
instrument must only be operated from 3 terminal power
connectors or via isolation transformers. In case of doubt
the power connector should be checked according to DIN
VDE 0100/610.
–The line voltage of the instrument must correspond to
the line voltage used.
pening of the instrument is allowed only to ualied
personnel
–Prior to opening the instrument must be disconnected
from the line and all other inputs/outputs.
In any of the following cases the instrument must be taken
out of service and locked away from unauthorized use:
–Visible damages
–Damage to the power cord
–Damage to the fuse holder
–Loose parts
–No operation
–After longterm storage in an inappropriate environment
, e.g. open air or high humidity.
–Excessive transport stress
1.6 Proper operating conditions
The instruments are destined for use in dry clean rooms.
Operation in an environment with high dust content, high
humidity, danger of explosion or chemical vapors is prohi-
bited. Operating temperature is +5°C ... +40 °C. Storage or
transport limits are –20°C ... +70 °C. In case of condensation
2 hours are to be allowed for drying prior to operation. For
safety reasons operation is only allowed from 3 terminal
It is prohibited to disconnect the earthed protective con-
nection inside or outside the instrument!
Exceeding the Low Voltage Protection!
For the series connection of all output voltages, it is pos-
sible to exceed the low voltage protection of 42 V. Please
note that in this case any contact with live components
is life-threatening. It is assumed that only qualied and
trained personnel service the power supplies and the
connected loads.
Important hints
Important hints
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Important hints
connectors with a safety ground connection or via isolation
transformers of class 2. The instrument may be used in any
position, however, sufcient ventilation must e assured as
convection cooling is used. For continuous operation prefer
a horizontal or slightly upward position using the feet.
Specications with tolerances are valid after a 30 minute
warm-up period and at 23 degrees C. Specications without
tolerances are typical values of an average instrument.
1.7 Warranty and Repair
Our instruments are subject to strict quality controls. Prior to
leaving the manufacturing site, each instrument undergoes
a 10-hour burn-in test. This is followed by extensive func-
tional quality testing to examine all operating modes and to
guarantee compliance with the specied technical data. The
testing is performed with testing equipment that is calibrat-
ed to national standards. The statutory warranty provisions
shall be governed by the laws of the country in which the
product was purchased. In case of any complaints, please
contact your supplier. Any adjustments, replacements of
parts, maintenance and repair may be carried out only by
authorized technical personnel. Only original parts may
be used for replacing parts relevant to safety (e.g. power
switches, power transformers, fuses). A safety test must
always be performed after parts relevant to safety have been
replaced (visual inspection, PE conductor test, insulation
resistance measurement, leakage current measurement,
functional test). This helps ensure the continued safety of
the product.
1.8 Maintenance
The instrument does not require any maintenance. Dirt may
be removed by a soft moist cloth, if necessary adding a mild
detergent. (Water and 1 %.) Grease may be removed with
benzine (petrol ether). Displays and windows may only be
cleaned with a moist cloth.
Do not obstruct the ventilation holes!
The product may only be opened by authorized and
qualied personnel. Prior to working on the product or
before the product is opened, it must be disconnected
from the AC supply network. Otherwise, personnel will
be exposed to the risk of an electric shock.
Before cleaning the measuring instrument, please make sure that
it has been switched off and disconnected from all power supplies
(e.g. AC supply network or battery).
No parts of the instruments may be cleaned with chemical clean-
ing agents (such as alcohol, acetone or cellulose thinner)!
1.9 Mains voltage and Changing the line fuse
A main voltage of 115 V and 230V can be chosen. Please
check whether the mains voltage used corresponds with
the voltage indicated by the mains voltage selector on the
rear panel. If not, the voltage has to be changed. In this case
the line fuse has to be changed, too.
The fuses are accessible from the outside and contained in
the line voltage connector housing. Before changing a fuse
disconnect the instrument from the line, the line cord must
be removed. Check fuse holder and line cord for any dama-
ges. Use a suitable screw driver of appr. 2 mm to depress
the plastic fuse holder releases on both sides, the housing
is marked where the screw driver should be applied. After
its release the fuse holder will come out by itself pushed for-
ward by springs. The fuses can then be exchanged, please
take care not to bend the contact springs. Reinsertion of the
fuse holder is only possible in one position and by pressing
against the springs until the locks engage. It is forbidden to
repair defective fuses or to bridge them by any means. Any
damage caused this way will void the warranty.
Types of fuses:
Size 5 x 20 mm; 250V~,
IEC 60127-2/5
EN 60127-2/5
Line voltage Correct fuse type
230 V 2 x 2,5 A slow blow
115 V 2 x 5 A slow blow
After changing the main voltage, the line fuse has to be changed.
Otherwise the instrument may be destroyed.
Important hints
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22
2 Operating Cont-
rols
Front panel
VOLT - Voltage display
AMP - Current display
LED - Current limit indicator
ELECTRONIC FUSE - Selector of functions electronic
fuse/current limit; LED will light if the electronic fuse
function is enabled
OUTPUT - Switching ON/OFF of all channels; LED
indicates status on
VOLTAGE /FINE - Fine/coarse adjustment of output
voltage 0...32 V
VOLTAGE - Adjustment of output voltage 0...5.5V
Operating controls
CURRENT - Adjustment of current limit Imax of
both current limit and electronic fuse threshold
0 – 32V / 2A - Safety terminals of the 32-V-out-
puts
0 – 5.5V / 5 A - Safety terminals of the 5-V-output
Power button
Rear panel
Voltage selector - Choice of mains voltage
(115 V/ 2 30 V )
Power receptacle with line fuse
Basics of power supplies
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Operating controls
3 Basics of Power
Supplies
3.1 Linear power supplies
Linear regulated power supplies excel by their highly con-
stant output voltage, low ripple and fast regulation, even
under high line and load transients. Good power supplies
feature a ripple of less than 1 mVrms which is mostly negle-
gible. Further they are free from EMI emission in contrast
to SMPS. A conventional mains transformer isolates the line
from the secondary which is rectied and supplies an un-
regulated voltage to a series pass transistor. Capacitors at
the input and output of the regulator serve as buffers and
decrease the ripple. A high precision reference voltage is
fed to one input of an amplier, the second input is connec-
ted mostly to a fraction of the output voltage, the output of
this amplier controls the series pass transistor. This analog
amplier is generally uite fast and is ale to keep the out-
put voltage within tight limits.
3.2 Switched-mode Power Supplies (SMPS)
SMS operate with very much higher efciencies than linear
regulated power supplies. The DC voltage to be converted
is chopped at a high frequency rate thus requiring only
comparatively tiny and light ferrite chokes or transformers
with low losses, also, the switching transistor is switched
fully on and off hence switching losses are low. In principle
regulation of the output voltage is achieved by changing the
duty cycle of the switch driving waveform.
1st Off-line SMPS
The line voltage is rectied, the uffer capacitor reuired is
of fairly small capacitance value because the energy stored
is proportional to the voltage squared (E = 1/2 x C x U2).
AC
voltage
mains transformer rectier actuator
analog control
output
reference voltage
REF
DC
voltage
GND
C1
OPVA
C2
B1
TR1
AC
voltage
mains
rectier rf-transformer rectier lter output
potential
seperation
DC
voltage
GND
switching
transistor
screening
OPVA
OC
B
control
GND
2nd Secondary SMPS
These still require a 50 or 60 Hz mains transformer, the
secondary output voltage is rectied, smoothed and then
chopped.
The capacitance values needed here for ltering the 100
resp. 120 Hz ripple are higher due to the lower voltage.
All SMS feature a very much higher efciency from appr.
70 up to over 95 % compared to any linear supply. They
are lighter, smaller. The capacitors on the output(s) of a
SMPS may be quite small due to the high frequency, but the
choice depends also on other factors like energy required
for buffering or ac ripple from the load (e.g. motors). In
principle the size of the major components decreases with
increasing operating freuency, however, the efciency
drops apppreciably above appr. 250 kHz as the losses in all
components rise sharply.
3.3 Parallel and Series Operation
It is mandatory that the power supplies used are denitely
specied for these operating modes. This is the case with
HM7043-5 power supplies. As a rule, the output voltages
to be combined are independent of each other, hence, it is
allowed to connect the outputs of one supply with those
of another or more.
Series Operation
The current limit of the outputs in series should be adjusted
to the same value. If one output reaches the current limit
the total voltage will break down.
AC
voltage
switching
transistor
rectier lter
output
DC
voltage
GND
transformer
OPVA
control
TR
DT
GND
mains
T
T
2
Q
2
Q
1
I
Basics of power supplies
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Parallel Operation
In order to increase the total available current the outputs
of supplies can be paralleled. The output voltages of the
supplies involved are adjusted as accurately as possible to
the same value. In this mode it is possible that one or more
supplies enter the current limit mode. The output voltage
remains in regulation as long as still at least one supply is
in the voltage control mode. It is recommended but not
asolutely necessary to ne adust the voltages such that
the individual current contributions remain nearly equal. Of
course, the maximum available output current is the sum
of the individual supplies‘ maximum currents.
Example:
A load requires 12 V at 2.7 A. Each 32 V output of the
HM7042-5 can deliver 2 A. First set both supplies to 12 V.
Then connect both black and both red safety connectors
respectively in parallel. The load is connected to one of the
supplies. With the pushbutton OUTPUT the voltage will
be turned on. It is normal that one output will current limit
at 2 A while the other will contribute the balance of 0.7 A
in voltage regulation.
3.4 Current Limit
Current limit means that a maximum current can be set.
This is e.g. useful in order to protect a sensitive test circuit.
In case of an inadvertent short in the test circuit the current
will be limited to the value set which will in most cases
prevent damage.
In case you should parallel power supplies of other manuf-
acturers with HM7042-5 power supplies make sure all are
specied for this mode of operation. If one supply of those
connected in parallel should have insufcient overload
protection it may be destroyed. HM7042-5 power supplies
are specied for series and parallel operation.
The picture shows that the output voltage Vout remains
stable, while the current I increases until the current limit
selected will be reached. At this moment the instrument
will change from constant voltage regulation to constant
current regulation. Any further load increase will cause
the current to remain stable while the voltage decreases
ultimately to zero.
3.5 Electronic Fuse
In order to provide a still better protection than current
limiting offers the HM7042-5 features an electronic fuse.
As soon as Imax is reached all outputs will be immediately
simultaneously disabled. They may be turned on again by
depressing OUPUT .
Basics of power supplies
In this mode the output voltages add, the output
current is the same for all supplies. As the sum of all
voltages may well surpass the 42 V limit touching
of live parts may be fatal! Only qualied and well
instructed personnel is allowed to operate such
installations.
I
out
Uout
Uconst
I
max
Iout
Uout
Uconst
Imax
Current limit
starts at 110% of I
max
short cut at
approx. 20% of I
max
Current limit
Adjustment of current
Adjustment of voltage
Concept of the HM7042-5
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Basics of power supplies
4 Concept of the
HM7042-5
In this instrument the advantages of a SMPS, especially
high efciency, and those of a linear regulator, e.g. high
quality regulation, are combined. A high power DC/DC
converter is used as a preregulator for the following linear
regulators, this reduces the high losses typical of purely
linear regulation. The HM 7042-5 has 3 independent and
isolated voltage sources. In addition to the standard mode
of operation as a triple output supply all outputs may be
series or parallel connected.
In series conncetion the maximum available current is
limited to 2 A. Paralleling the two 32 V outputs will yield 4
A at a maximum of 32 V. Please note that series as well as
parallel conncetion may inuence some specications valid
such as output impedance, noise, regulation.
4.1 Output power of the HM7042-5
The maximum combined output power is 155.5 W. The
HM7042-5 has a temperature-controlled fan the rpm of
which will increase with rising temperature. This will ensure
sufficient cooling under all normal operating conditions.
4.2 Switching the display on/off
All HM7042-5 power supplies feature a pushbutton which
turns the outputs ON/OFF while the supply remains func-
tioning. This allows to preset all voltages to their respective
desired values prior to turning the outputs on by depressing
OUTPUT .
Exceeding the Low Voltage Protection!
For the series connection of all output voltages, it is pos-
sible to exceed the low voltage protection of 42 V. Please
note that in this case any contact with live components
is life-threatening. It is assumed that only qualied and
trained personnel service the power supplies and the
connected loads.
5 Introduction to
the operation
5.1 First time operation
Please observe especially the following notes:
– The line voltage indicated on the rear panel corresponds
to the available line voltage, also, the correct fuses for
this line voltage are installed. The fuses are contained
in the line voltage connector housing.
–The connection to the mains is either by plugging into
a socket with safety ground terminal or via an isolation
transformer of protection class II.
–No visible damage to the instrument.
–No visible damage to the line cord.
No loose parts oating around in the instrument.
5.2 Turning on the HM7042-5
After turning on all outputs will remain disabled, protecting
the loads. Prior to pressing OUPUT all output voltages
should be set to their desired values. Also, after turn-on the
instrument will be in the operating mode “Current limit“. The
maximum current available can be set by CURRENT
. The mode “Electronic fuse“ may be selected after turn-on,
but after each turn-off-on cycle “Current limit“ will be set.
Concept of the HM7042-5
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26
6 Operating controls
and displays
6.1 Channel I + III
0 – 32 V / 2 A
Output voltage, adjustable 0 – 32 V. Safety terminals for
4 mm plugs. The outputs are short circuit-proof with no
time limit.
VOLT
4 digit displays (7 segment LEDs), of the actual values of
all voltages, the resolution is 10 mV. The display are always
operative, even when the outputs are disabled allowing pre-
setting of all output voltages before the loads are connected
to them. We recommend to follow always the procedure of
setting the output voltages rst and then turn the outputs on.
LED
These LEDs will light up if current limit is reached.
AMP
4 digit displays (7 segment LEDs) of the actual output cur-
rents, resolution 1 mA. We recommend to set the output
current (Imax) before setting the output voltage and then
turn on the outputs.
VOLTAGE /FINE
otary controls for the coarse/ne adustment of the 0  32
V outputs.
0 – 32 V / 2 A
Outputs, 4 mm safety connectors
CURRENT
Rotary controls for setting the maximum currents of the 0
– 32 V outputs. If a control is turned CCW to 0 A all outputs
will be turned off immediately if the function “electronic
fuse“ was activated. In case “Current limit“ was selected
the LEDs will light up, the voltage will drop to zero.
0 – 5.5 V / 5 A
This output voltage can be adjusted 0 – 5.5 V. 4 mm sa-
fety connectors. This output is short-circuit proof without
a time limit.
6.2 Channel II
VOLT
3 digit displays (7 segment LEDs) of the actual output
voltage, resolution 10 mV. This display will show the output
voltage even if the output was switched off. We recommend
to follow always the procedure of setting the output voltage
rst and then turn the output on.
LED
If the current limit Imax is reached this LED will light up.
AMP.
3 digit displays (7 segment LEDs) of actual output currents,
resolution 10 mA. We recommend to set the output current
Imax prior to turning on the output voltages.
VOLTAGE
Rotary control for setting the 0 – 5.5 V
0 – 5.5V / 5 A
Output, 4 mm safety connectors.
CURRENT
Rotary control for setting the maximum output current 0
–5A. If the control is turned CCW to 0 A all outpts will be
turned off immediately if the mode “electronic fuse“ was
selected. In “current limit“ mode the LED will light up,
the voltage will drop to zero.
Operating controls and displays
Operating controls and displays
北京海洋兴业科技股份有限公司（证券代码：839145）
www.hyxyyq.com

ELECTRONIC FUSE
This pushbutton will activate the electronic fuse mode,
indicated by LED [ON].
OUTPUT
Pushbutton for turning all 3 channels simultaneously ON/
OFF, indicated by the LED [ON]. The voltage displays will
remain unaffected.
6.3 Current Limiting
After turn-on of the power supply it will always start in the
CURRENT LIMIT mode. Using the CURRENT con-
trols the maximum output current Imax can be set for each
output separately. Onset of current limiting in one channel
will not inuence the others. In order to adust Imax the
appropriate output has to e short-circuited rst, then Imax
can be set, the associated LED or will light up and
indicate the current limit mode.
6.4 Electronic Fuse
Prior to selection of this mode the current limits have to be
set using the CURRENT controls. As outlined each
output has to e short-circuited rst efore adusting the
appropriate CURRENT control. After setting Imax, the short
has to be remov-ed. Then Electronic Fuse is depressed,
the LED [ON] will light up indicating that the HM7042-5 is
in the Electronic Fuse mode. In this mode all outputs will
be immediately deactivated if the Imax of one channel is
reached. In order to leave this mode press Electronic Fuse
again.
The current limits can be set using the controls CURRENT
0 – 2 A / 0 – 5 A. If a control is set CCW to 0 A indeed the
current will be zero, so the output capacitances will be dischar-
ged slowly to 0 V. In “Current Limit“ mode the CCW position of
a control will cause the associated LED to light up, the
output voltage will decrease slowly. In the Electronic Fuse mode
the CCW position of any CURRENT control will result in immedi-
ate switching off of all channels after depressing OUPUT .
Operating controls and displays
Operating controls and displays