Tenma 72-7675 User manual

72-7675
Contents
1. SAFETY TERMS AND SYMBOLS ......................................1
2. INSTALLATION.....................................................................2
3. OPERATION...........................................................................5
4. PANEL DESCRIPTION .......................................................10
5. CIRCUIT PRINCIPLE.........................................................13
6. BLOCK DIAGRAM .............................................................14
7. SPECIFICATIONS ...............................................................15
8. MAINTENANCE ..................................................................17
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1. SAFETY TERMS AND SYMBOLS
These terms may appear in this manual or on the product ：
：：
：
WARNING ：
：：
： Warning statements identify condition or
practices that could result in injury or loss of life.
Caution ：
：：
： Caution statements identify conditions or
practices that could result in damage to this product or
other property.
The following symbol may appear in this manual or on the
product ：
：：
：
Attention refer to Manual.

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sel ect swi t ch
230V
2. INSTALLATION
1) Before installation, please make sure the AC input voltage is
correct.
The AC input voltage of 72-7675 is either 115V or 230V, which
can be selected. The select switch is located on the rear panel.
2) Before connecting the power cord to the suitable outlet, please
make sure all the 72-7675’s breakers are turned off. It will
avoid the unnecessary accident or damage to the unit.
3) Plug the input power cord to the suitable outlet.
4) Please make sure the input tolerance is within ± 10% of rated
voltage (see figure 1).
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Figure 1
Max
Output
Voltage
150/300
120/240
100/200
85
90 95 115
100
% of Rate
Input Voltage

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5) The size of input wire and output wire.
Input Wire Size
Model 115V 230V Output Wire Size
72-7675 AWG#14 0.75mm
2
AWG#18
6) An AC power cord is included with the unit.
7) The Selection of Output Test Lead:
For safety assurance, please select the adequate output test
lead according to the following list:
ConductorUL
(CSA)
Model
Wire
No.
AWG
Component
pc/mm
Cross
Section
Area
(mm)
2
Outer
Diameter
mm
Maximum
Conductive
Resistor
Ω /km
Permissible
Current
A(amp)
24 11/0.16 0.22 0.64 88.6 7.64
22 17/0.16 0.34 0.78 62.5 10.0
20 21/0.18 0.53 0.95 39.5 13.1
18 34/0.18 0.87 1.21 24.4 17.2
16 26/0.254 1.32 1.53 15.6 22.6
14 41/0.254 2.08 2.03 9.90 30.4
12 65/0.254 3.29 2.35 6.24 40.6
1015
TEW
(Twisted
Wire)
10 65/0.32 5.23 3.00 3.90 55.3
Remark:
a) The ambient temperature of “Permissible Current” is at
40 ℃ , the withstanding temperature of conductor is at
105 ℃ according to the condition of the distributed
single wire.
b) The permissible current listed as above is suggested to
be used under 70%.
c) When the current value exceeds above suggestive list,
can select more wires used in parallel according to
above list.
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3. OPERATION
Voltage Setting:
Voltage setting contents “110V”, “220V”, “ ▲ ” and “ ▼ ” four
keys.
a. When any one of the keys mentioned above is pressed, the
voltage display will flash one time, the unit will go to the
setting mode and show the voltage setting value.
b. If the “110V” Key is pressed, the output voltage will be
adjusted to 110V immediately. Meanwhile, the voltage
display will switch back to the reading mode automatically.
c. If the “220V” key is pressed for 0.2 seconds continuously
(for safety reason, must be), the output voltage will be
adjusted to 220V. Meanwhile, the voltage display will switch
back to the reading mode automatically.
Note: It will not work if the output voltage is setting on
low range (0~150V output)
d. If either “ ▲ ” or “ ▼ ” key is pressed for 0.5 seconds, the
output voltage will be adjusted. If either “ ▲ ” or “ ▼ ” is
pressed twice, the output voltage will be adjusted
immediately.
e. The adjusting rates are 0.1V/step on fine adjust mode and
1V/step on coarse adjust mode.
f. The first six steps of adjustment will be spent 0.25 seconds
per step. If the key “ ▲ ” or “ ▼ ” is pressed continuously, it
will spend 0.13 second per step for the rest steps. If the key
is released, the voltage adjustment would be stopped and go
back to the original adjustment speed (0.25 seconds per step)
automatically.
g. If the output mode is setting ON (the indicator “OUTPUT”
would light), the output voltage could follow the setting
voltage simultaneously.

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Caution: If there is no function test of voltage “ ▲
▲▲
▲ ” or
“ ▼
▼▼
▼ ”,the voltage output mode would be suggested to
switch to “OFF” status for avoiding unnecessary
mistakes occurring.
h. If any key mentioned above is not pressed for 2 seconds
continuously, the unit will go back to the normal operation
and the voltage display could show the reading value
automatically.
Frequency Setting:
Frequency setting contents “50Hz”, “60Hz”, “ ▲
▲▲
▲ ” and “ ▼
▼▼
▼ ” four
keys.
a. If the key “50Hz” or the key “60Hz” is pressed, the frequency
will be changed immediately to 50Hz, 60Hz respectively.
Meanwhile the output frequency will be changed
coincidentally.
b. The frequency ranges from 45Hz to 99.9Hz can be adjusted by
0.1 Hz per step in fine adjustment mode and 1 Hz per step in
coarse adjustment mode. The frequency ranges from 100Hz to
500Hz can be adjusted by 1 Hz per step in fine adjustment and
10Hz per second in coarse adjustment mode.
c. The other settings are the same as voltage setting.
High / Low Voltage range selection:
Press the key of “RANGE”, if the indicator lights, the output
voltage would be setting on the high voltage range, otherwise, the
system would be setting on low voltage range. The changed range
would not cause the setting voltage to change, however, there is a
20ms interruption during the voltage range changing. The
non-reasonable range changing (For example, the voltage sets
200V but the range is changed to the low range) is not acceptable
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this unit.
Note: High range voltage 0 ~ 300V
Low range voltage 0 ~ 150V
Instrumentation selection:
a. Pressing the “A” key will light the current indicator and the
LED display will show the value of current.
b. Pressing the “W” will light the power indicator and the LED
display will show the value of wattage.
c. Pressing the “PF” key will light the power factor indicator
and the LED display will show the value of power factor.
Output Enabled and Disabled Operation:
Press the key of “OUTPUT”. If the output indicator lights, the
output is enabled, and the LED display will show the output value
(reading value). Otherwise, the output function is disabled, and the
LED display will show the setting value. Press the “OUTPUT” key
again to change the mode.
Lock Function:
Press the key of “LOCK”, if the lock indicator lights, all the keys
are Locked (except the alarm reset). This function is good for
avoiding any mistakes of key pressed during operation. Press again
to change the mode.
Alarm Reset:
If an over current event occurs, the 72-7675 will shut down and
buzz immediately. You must press “ALARM RESET” to clear. In
addition, the “OUTPUT” key must be pressed to return to normal
output voltage.

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Memory Function:
The 72-7675 is equipped with EEPROM, the latest setting will be
memorized after the unit is turned off. When the unit is turned on
again, the latest setting will be displayed.
Save/Recall Function:
Press the key of “S/R”, if the indicator of SAVE/RECALL doesn’t
light. Press any one of “MEM1”, “MEM2”, “MEM3” and
“MEM4” keys for 0.2 seconds, the current output setting will be
saved. If the indicator of SAVE/RECALL lights, press any one of
“MEM1”, “MEM2”, “MEM3” and “MEM4” keys for 0.2 seconds,
the setting saved last time by the same key will be recalled as
current setting.
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4. PANEL DESCRIPTION
(1) “ALARM RESET” Key
Reset key to cease the buzz and reset the output.
(2) “S/R” Key
Save or Recall function selecting key.
(3) “SAVE/RECALL” Indicator
In the mode to save setting, the indicator doesn’t light. In the
mode to recall setting, the indicator lights.
(4), (5), (21), (22) “MEM1”, “MEM2”, “MEM3” and “MEM4” Keys
When the “SAVE/RECALL” indicator is off, the four keys are for
saving four different settings. When the indicator is on, the keys
are for recalling the saved settings.
(6), (23) “50Hz” and “60Hz” Keys
One touch key for 50Hz and 60Hz output respectively.
(7) Output Frequency LED Display:
If the ‘OUTPUT’ key isn’t pressed, the indicator doesn’t light,
and the setting frequency value will be displayed on the output
frequency LED display. If the ‘OUTPUT’ key is pressed, the
indicator light, and the output frequency value will be displayed
on the output frequency LED display.
(8), (24) “ ▲ ” and “ ▼ ” Keys
The two keys are for frequency setting, to increase or decrease the
frequency value respectively every time they are pressed. The
adjusting rate depends on the ‘COARSE’ key and the frequency
value itself.
(9) Coarse Indicator
If the coarse adjustment mode is selected, the coarse indicator will
light. If the fine adjustment mode is selected, the coarse indicator
does not light.
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(10) High/Low Range Indicator of Output Voltage
If this indicator lights, the output voltage is in the range 0~300V.
If this Indicator does not light, the output voltage is in the range
0~150V.
(11), (27) “110V” and “220V” Keys
One touch key for 220V and 110V output respectively.
(12) Output Voltage LED Display
If the “OUTPUT” Key is not pressed, the indicator doesn’t light,
and the setting value will be displayed on the Output Voltage LED
Display. If the “OUTPUT” key is pressed, the indicator lights, and
the output value will be displayed on the Output Voltage LED
Display.
(13), (28) “ ▲ ” and “ ▼ ” Keys
The two keys are for voltage setting, to increase or decrease the
voltage value respectively every time they are pressed. The
adjusting rate depends on the “COARSE” key.
(14) Function of Ammeter Indicator
If ammeter’s indicator lights, the value of output current will be
displayed on the multimeter LED display.
(15) Function of Wattage Meter Indicator
If wattage meter’s indicator lights, the value of output wattage will
be displayed on the multimeter LED display.
(16) Multimeter LED Display
The value of output current, wattage or power factor will be
displayed by respective key from “A”, “W”, to ‘PF’.
(17) Function of Power Factor Meter Indicator
If power factor meter’s indicator lights, the value of output power
factor will be displayed on the multimeter LED display.
(18) “OUTPUT” Key
Output function enabled/disabled selection key.

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(19) Output Indicator
When output is enabled, the output indicator will light.
(20) Power Switch
To turn on /off 72-7675.
(25) “COARSE” Key
Coarse/Fine adjustment selection key.
(26) “RANGE” Key
For the high/low output voltage’s range selection.
(29) “A” Key
Ammeter selection key of multimeter LED display
(30) “W” Key
Wattage meter selection key of multimeter LED display.
(31) “PF” Key
Power factor meter selection key of multimeter LED display.
(32) “LOCK” Key
Lock/Unlock keyboard selection key.
(33) Lock Indicator
The lock indicator lights to indicate the keyboard is locked. All
other keys except ‘RESET’ are disabled.
(34) Outlet
Output socket
Caution: The maximum AC voltage is up to 300V. Do
not touch the output sockets when the OUTPUT
indicator appears lit.
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5. CIRCUIT PRINCIPLE
This power supply is controlled by CPU and operated via
keyboard. The unit is fully digital controlled.
The input isolation transformer has been applied to isolate the city
power and step down the input voltage for appropriate applications.
The main AC power is rectified and filtered to become a very smooth
DC source for power amplifier. Sine wave form is generated by the
digital synthesizer and filtered by a very high impedance filter.
Therefore, the sine wave form will be very stable and the distortion
will be reduced.
The unit has two voltage feedback systems. One is analog
feedback system for quick response (within 100us), and the
regulation will be located in the range of ± 5%. The other is digital
feedback system. The system will read the output voltage and
compare with the settings. The accuracy of Output voltage will be
limited in the range of ± 0.1V.
The sine wave signal is amplified by power amplifier. The power
amplifier provides a very clean and low distortion sine wave to the
output of APS series through the output transformer. The offset and
calibration data of instrumentation are stored in the EEPROM. The
instrumentation will be calibrated automatically when the unit is
switched on. True RMS circuit is applied for the voltmeter and
ammeter. The value of LED display is true RMS value.
For easy operation, the power supply has a EEPROM memory.
The EEPROM will memorize the latest data settings automatically
after the unit has been switched off. When the unit is switched on
again, the CPU will read the data from the EEPROM and provide the
same output value as the previous setting. It is unnecessary to reset
the data after the unit has been turned off.

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6. BLOCK DIAGRAM
I/P
C
P
U
Keyboard
Display
Voltage
Control
Frequency
Control
Frequency
Sensor
Memory
A/D
Isolated
Transformer
Rect. /
Filter
Power
Amplifier
Sine wave
Synthesizer
Output
Transformer
Current &
Voltage
Feedback
Current &
Voltage
Sensor
O/P
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7. SPECIFICATIONS
Specification Description
Output
Frequency
(45.0~500Hz)
Digital setting via keys, Resolution: 0.1Hz
Accuracy: ±0.1Hz
Output Voltage
(AC0.0~300.0V)
Digital setting via keys, Resolution: 0.1Vrms
Accuracy: ±1%rdg+1digit AC40.1~ 300.0V)
Resolution: 0.1Vrms
Accuracy: ±1%rdg+5digitAC0.0~ 40.0V)
Output Capacity
Low voltage range: 0.0 ~ 150Vac
High voltage range: 0.0 ~ 300Vac
Output Power 500VA(72-7675);
Maximum
Current 72-7675: 4.2A(0~150V), 2.1A(0~300V)
Line Voltage
Regulation ±0.1%
Load Regulation ±(0.5%+0.1V)
Protection Key Lock, OCP, Short Circuit Protect OTP
Frequency
Stability
≦ 100ppm
Wave Distortion
0-150V 22V~125V
≤
0.5%THD.(Resistance Load)
0-300V 44V~280V
≤
0.5%THD.(Resistance Load)
Digital Display:
Frequency
Counter
Measuring Range ： 0.0~999Hz
Resolution ： 0.1Hz
Accuracy ： ±0.1Hz
RMS Voltmeter
Measuring Range ： AC0.0 ~ 380V
Resolution ： 0.1Vrms
Accuracy ： ±1% Rdg+1Digit
RMS Ammeter
Measuring Range: 0.000~2.000A 1.80~35.00A
Resolution: 1mA(<360w) 0.01A
Accuracy: ±1% rdg
+5 digits
±1% rdg
+2 digits

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Specification Description
Wattage Meter
Measuring Range: 0.0~360W(<2A) 320~3500W
Resolution: 0.1W 1W
Accuracy ： ±1.5% rdg+5digits
±1.5% rdg+20digits( ≤ 0.3A)
Line Input
Requirement
115/230Vac±10%, 47-63Hz, 1 phase
Calibration Front Panel Software Calibration
AC Power
consumption Maximum 2.8kW
Operation
Environment
Indoors
Rated Temperature ： +10
0
C ~+35
0
C
Operating Temperature: +0
0
C ~+40
0
C
Storing Temperature ： -10
0
C ~+70
0
C
Relative Humidity:<80%
Accessory Operation manual……………..
× 1
Line cord……………………… × 1
Dimensions 137mm(H) × 430(W) × 500mm(D)
Weight Approximate 25kgs
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8. MAINTENANCE
Cleaning
Use a soft cloth moistened with a small amount of water or mild
detergent, Do not spray cleaner directly onto the instrument as it may
leak into the cabinet and cause damage.
Do not use chemicals containing benzine, benzene, xylene, acetone,
toluene, or similar solvents.
Do not use abrasive cleaners on any portion of this equipment.
Troubleshooting
Troubleshooting is limited to checking the input power fuse. If you
have other difficulties, please contact your supplier or a competent
repair specialist.
Warning ：
：：
： To avoid electrical shock ，
，，
， the power cord
protective Grounding conductor must be connected to
ground.