Tenma 72-8795 User manual

User's Manual
72-8795
PROGRAMMABLE DC
POWER SUPPLY
405 S. Pioneer Blvd
Springboro, OH 45066
mcmelectronics.com

72-8795
PROGRAMMABLE DC
POWER SUPPLY
Programmable DC Power Supply Series
Thanks for using our products. Please read this
manual thoroughly before operation.

2
CONTENTS
Safety Symbols
Product Introduction
Product Overview
Additional Features
Specifications of Product
Precautions before operation
Unpacking
Checking the Voltage
Operating Environment
Panel Introduction
Layout of the Front Panel
Layout of the Rear Panel
Function Description
Operating Instructions
Output Voltage Setting
Output Current Setting
OCP Setting
Voltage / Current Step Setting
Data Storing and Recalling Setting
Automatic Sequence Mode
Series and Parallel Operation
Communication Settings
Maintenance
Fuse Replacement
Adjustment and Calibration
Cleaning
[Step 3]
After zeroing the voltage of the three channels, which are also saved, move
the cursor to [CURRENT] of [CH1]. Connect the ammeter and adjust the knob
to make the current reading equal 0MA. Then press [ENTER] to store the calibration
data of the corresponding channel. Move the cursor down to zero and calibrate the
current of channel 2 and channel 3 with the same procedure.
[Step 4]
After completing step 3, move the cursor to the left; press key 2(cursor down) until
the calibration interface reads “Output Calibration”. Move the cursor to a
corresponding channel and adjust the output voltage by using the rotary knob to
equal 32V reading on the voltmeter. Press [ENTER] and then the calibration data
of the corresponding channel is stored. Move the cursor down into the calibration of
the other channels with the same procedure, with channels 1 and 2 at 32 V, and
channel 3 at 6 V.
[Step 5]
After completing the maximum voltage calibration, connect the ammeter and adjust
the current of channel 1 to equal 3A. Press [ENTER] to save the current of the
channel. Then move the cursor to carry on with the current calibration and storage of
channel 2 and channel 3.
When the unit is unplugged, use a damp cloth or mild cleanser to wipe the housing.
Never use an abrasive cloth or harsh solvents, as these will damage the housing of
the instrument.
3. Cleaning
ZERO CALIBRATION
CH1Votage Current
CH2Votage Current
CH3Votage Current
H
CH1Votage Current
CH2Votage Current
CH3Votage Current
OUTPUT CALIBRATION H
CH1Votage Current
CH2Votage Current
CH3Votage Current
OUTPUT CALIBRATION H
15
3
4
4
4
5
6
6
6
7
7~9
7
8
8~9
10~12
10
10
11
11
11
11
12
12
13~15
13
14
15
GENERAL MAINTENANCE
CONTENTS

3
!
!
14
Safety Symbols
SAFETY SYMBOLS
WARNING: Warning statements identify conditions or practices to avoid
electric shock that could cause personal injury or death.
CAUTION: Caution statements identify conditions or practices that
could result in damage to this product or other property.
Ground; Ground terminal
Frame or chassis ground terminal
1. Pressure, shock, abuse, and vibration should be avoided.
2. Do not dismantle, alter, or repair this unit yourself. This could easily damage
the unit, and could cause further property damage, injury, or electrical shock.
3. This unit was designed to be used with 110 volt power. Note the maximum power
and amperage settings, and fuse specifications for use with this product.
4. This unit uses three linear power supplies, and has been designed to ensure that the
machine casing and power are properly grounded when used with a grounded outlet.
5. Never use around high moisture areas, never submerge in water, and never use
with wet hands.
6. Range of operating temperature is 0°C~40°C (32 ; do not use in
high temperature, high humidity, high radiation, and areas with magnetic interference.
°F ~ 104°F)
Safety Precautions
2. Adjustment And Calibration
2.1.1 Preparation
a. Power unit on and allow 30 minutes to warm up before calibration.
b. Ambient temperature: 23±5°C, Humidity: Less than RH80%.
c. Select a reliable six-and-a-half digital voltmeter with a current test
range more than 5A.
2.1.2 Output Calibration Steps:
[Step 1]
Press [SHIFT][4] to display Password input window, input Password
(293856) by using the number keys, and the Calibration window will
appear. If an incorrect password is entered, the unit returns to the
home screen.
[Step 2]
Control the cursor by using the arrows assigned to the 8, 2, 4, 6 keys.
Set the cursor to the calibrated item of the corresponding channel, and
using a connected voltmeter for correct readings, use the rotary knob
to adjust parameters and regulate the voltage of the corresponding
channel to a 0V reading on the voltmeter. Press [ENTER] to store the
calibration data of the corresponding channel. Move the cursor down
to calibrate the other channels with the same procedure.
Tip: Use the F/C feature to switch between broad and precise incremental
control.
Password
******
Zero Correct
CH1Votage Current
CH2Votage Current
CH3Votage Current
H
GENERAL MAINTENANCE

4
● Programmable power supply with a digital interface
● Three separately adjustable linear outputs
● The 192×64 LCD Display can display multiple settings and measurements simultaneously
● Windows-based interface for user-friendly operation
● High stability and low drift
● Over Voltage, Current, and Temperature protection
● Intelligent fan control adjusts with output power
● Built-in warning buzzer
● Accurate user calibration software
● Space-saving design
● Fine adjustment knob
● 90 setting memory
● Parallel, series, and independent operation modes
● 1-second timing resolution.
13
PRODUCT INTRODUCTION
Product Overview
72-8795 Programmable Power Supply is controlled by a Micro Processor
Unit (MPU) that is designed for a communication interface by RS-232 or USB to
computer to enable advanced testing and power delivery by programmable control.
The volt a ge an d cur r e nt a r e con t r oll e d by a 12 b it D / A Conv e r t e r
with high resolution and accuracy. Also, the digital interface provides
a speedy, precise and convenient input of information controlled by intuitive controls.
The adjustment of voltage/current is made by software calibration, eliminating
potential manual fault, that increases the precision of the instrument.
Over Voltage Protection (OVP) and Over Current Protection (OCP) can be set with the
software and utilized by the hardware to achieve precise, instant protection
t o p r e v e n t d a m a g e a n d i n c r e a s e t h e u s e r s ’ s a f e t y .
We warrant this unit to be free from manufacturer material and workmanship defects
for one year from the original date of purchase within North America. If the unit fails
during normal use withing the warranty period, please contact the authorized reseller
of this product for repair or replacement. This warranty does not apply to defects
and failure resulting from customer actions, such as mishandling, misapplication,
overloading power or current, unauthorized repair, or any modification. The reseller
and manufacturer hold the right to deny any warranty claims based on these reasons,
or to fulfill warranty with a similar product at a similar value.
Additional Features
CH1
OFF
CH1
OFF
32. 00V
32. 00V
32. 00V
32. 00V
0 6 . 00V
0 6 . 00V
3 . 0 0 0 A
3 . 0 0 0 A
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
S h i f t
PARA
SERI
OCP
OFF
OCP
OFF
3 . 0 0 0 A
3 . 0 0 0 A
CH3
OFF
CH3
OFF
CH2
OFF
CH2
OFF
OCP
OFF
OCP
OFF
OUT SET
INDEP OUT
PARA OUT
SERIES OUT
OUT SET
INDEP OUT
PARA OUT
SERIES OUT
8. Communication Setting
Press [SHIFT][COMM] to access the interface for the communication setting.
Use the key directions to move the cursor to the corresponding value place. You
can set the power address, communication speed and data bit by using the rotary
knob to change the values. Press [ENTER] to store and exit.
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
04. 1 0 V
2. 000A
2. 000A
S h i f t
INDEP
OCP
OFF
2. 000A
CH3
OFF
CH2
OFF
OCP
OFF
INTERFACE
ADDR: 001
BAUD: 19200
DATA: 9
GENERAL MAINTENANCE
General Maintenance
To avoid electrical shock, do no perform any service or repair other than those outlined in these
operating instructions. Any additional attempts at servicing or modifying this unit voids all
manufacturer warranty and liability.
1. Fuse Replacement
If the fuse blows, the display will not light and the power supply will not operate.
Replace the fuse with a compatible rated fuse. The unit was originally supplied with a 5 Amp
250V glass type fuse. The fuse compartment is located at the AC plug terminal
WARNING: Replace fuse only with 250V fuse of the specific type and
rating, and always disconnect power cord before replacing fuse.
Parallel Output Mode
Serial Output Mode

5
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 0 0 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
AUTO
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 0 0 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
OUT SET
INDEP OUT
PARA OUT
SERIES OUT
12
Programming Output Mode
Independent Output Mode
TECHNICAL SPECIFICATIONS
5.2 Sequence range activation
After setting all needed values and delays, move the cursor over the delay value
of the last step in the sequence to be used and press [AUTO], and a box
should appear after the value. After the automatic sequence reaches this step, it
will return to the first step and continuously repeat the sequence.
6. Automatic sequence execution
From the home screen, press [AUTO], which will set the unit to AUTO mode.
Press [OUTPUT] to activate the selected and stored settings; the unit then will
output the sequences of t voltage, current, and delay parameters. The unit will
continued to run through the sequences. Press [AUTO] to stop the automatic
sequence.
7. Series and parallel operation mode
Press [SHIFT][ PARA/SER] to select between operation modes. Use the rotary
knob to select the desired output mode. Press [ENTER] to confirm and return to
the main screen. When the unit operates in series or parallel output modes,
channel 2 operates as the master (CH1 and CH2 will output the settings for Ch2).
In independent mode, each channel will output it’s own individual settings.
72-8795
≤3mV(AC±5%)
≤3mA
10mV
Resolution
100ppm+3mV
100ppm+3mA
10%~90%≤ 100ms
90 10 10 ( 10 rated load)%~ %≤ ≥ % ms
Technical specifications
Specifications
Note: The following indexes are tested after unit being powered for 20 minutes.
Output
Voltage
Current
Load Effect Voltage
Current
≤3mV(≤8mV rated >3.0A)current
0~32V 2,
0-6V
x
0~3A 3 x
≤3m (≤m rated current>3.0A)A 5 A
Voltage
Current
Power Effect
Voltage
Current
≤0.05 +10 mV(+20 mV rated voltage>36V)%
≤0.1 +5ma(+10 mA rated current>3.0A)%
Voltage
Current
Voltage
Current
Set
Accuracy
(25 5 )±℃
Ripple
(20Hz-20MHz) ≤3mArms(≤5mArms rated current>3.0A)
Voltage
Current
Temperature
Coefficient
(0～40℃)
Voltage
Current
10 mV
1mA(2mA rated current>3.0A)
1mA（2mA rated current>3A）
Ripple≤1 mVrms
Read back
Resolution
Voltage rise
Current fall
Response Time
Voltage
Current
≤100ppm+10 mV
≤150ppm+10 mA
≤100ppm+10 mV
≤150ppm+10 mA
≤0.1 +20 mV%
20 mA
Series(Load)
Drift Voltage
Current
Readback
Temperature
Coefficient
OPERATION
Serial
synchronous
operation
Serial
synchronous
error

Auto Step running
6
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 0 0 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
STORE SET
CH1 STORE
CH2 STORE
CH3 STORE
CH1 STORE
1 : 32.00 V 2.000A 0001S
2 : 43.50 V 1.253A 0002S
3 : 55.19 V 1.376A 0002S
11
Voltage≤5mA
Current≤6mA
Voltage≤0.05%+20 mV
Current≤0.1%+20 mV
Set
Accuracy
Parallel
Simultaneous
Operation
Load regulation
Power
regulation
Voltage≤3 mV
Current≤6mA
Memory Store/Recall points 0~90
Timer
1s~9999s
1s
Resolution
Setting time
Function
Interface RS232,USB interface
230（W）×140（H）×380（L）mm
10Kg (22 lbs)
Indoor use, Altitude up to 2000 m
Dimensions
Weights
Physical
Specification
Operation Environment
Precautions before operation
1.Unpacking the Instrument
The product has been fully inspected and tested at our factory before shipping.
Please carefully unpack and inspect it to check if there is any damage that may have
occurred during transportation. If any signs of damage are found, please contact our
customer service team before operation.
2. Power requirements
The product has been designed to be used with 110V 60Hz power supplies. Make
certain that the power supply and outlet are properly grounded before use. Do not
modify the power plug or cord in any way. Use only the power cable that is included
in the packaging, or a direct replacement.
Example: Set current at 1.500A.
Press [I SET][1][.][0][0][0][ENTER]
If the load current through output terminals exceeds the setting value, the
instrument will operate in the C.C. mode; if load current does not exceed the
setting value, the instrument will operate in the C.V. mode.
3. Over Current Protection Setting
Press[OCP] to turn on the OCP mode. OCP mode is can be turned off by
pressing [SHIFT][OCP].
4. Voltage/Current Step Setting
While using the rotary knob for changing value, pressing F/C will switch between
macro and micro incremental values to either rapidly change or fine tune values.
5. The data storage and call setting
5.1 The data storage setting
Press [SHIFT][STORE] to access the data store menu screen. Use the rotary knob
to select the channel group, and then press ENTER. Move the cursor selection
by pressing the direction key (8,2,4,6) to select voltage, current and delay time;
press ENTER, then you can input data directly. Press ENTER again to store.
Example: To set output voltage, current and delay time of the CH1 memory of “ 01”
to be 15.00V, 3.00A, 20S. Press [SHIFT][STORE] to access menu screen,
and us rotary knob to select Ch1 STOREl. Then press ENTER to access CH1
storage interface; move the cursor to the voltage and press ENTER to input
voltage with number keys or rotary knob, and then press ENTER to store
data. Repeat for current and delay settings. Press [SHIFT][STORE] to store
all settings.
OPERATION
TECHNICAL SPECIFICATIONS

7
!
22
11
33
9988
72-8795
445566
77
10101111
1212
13131414 1515 1616
1717
1818
1919
2020
2121
2222
2424
2323
10
CH1
OFF
V
3 2 . 0 0 V
0 6 . 00 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 0 0 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
2525
CAUTION: To avoid personal injury and damage, disconnect the
power cord before removing the fuse holder.
3. Operation Environment
The working ambient temperature range of this instrument is from 0° to 40°C
(32° to 104°F). Do no operate the instrument outside of this range. Extreme
temperatures can cause damage to the unit.
WARNING: To avoid electrical shock, make sure the power cord has
been securely connected to a properly grounded outlet.
PANEL INTRODUCTION
Panel Introduction
Layout of Front Panel
OPERATION
Operation
1.Output Voltage Setting
Select the desired channel by pressing [SHIFT][CH#] to set the cursor
to toggle that channel.
Method 1: Set output voltage by pressing [V SET] and using the number and
decimal keys to key in [voltage value], then press [ENTER].
Method 2: Press [V SET], press the rotary knob once, and turn the rotary knob
to input [voltage value]. The output voltage setting is changed
immediately during selection. Press [ENTER] to save the voltage
setting.
Example: To set voltage at 18.50V.
Press [V SET][1][8][.][5][0][ENTER].
2. Output Current Setting:
to toggle that channel.
Method 1: Set output current by pressing [I SET] and using number keys to key in
[current value], then press [ENTER].
Method 2: Press [I SET], press the rotary knob once, and turn the rotary knob
to input [current value]. The output current setting is changed
immediately during selection. Press [ENTER] to save the current
setting.
Select the desired channel by pressing [SHIFT][CH#] to set the cursor
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 00 V
A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
CH1
OFF
3 2 . 0 0 V
3 2 . 0 0 V
0 6 . 0 0 V
3 . 0 0 0 A
3 . 0 0 0 A
S h i f t
INDEP
OCP
OFF
3 . 0 0 0 A
CH3
OFF
CH2
OFF
OCP
OFF
PROGRAMMABLE DC POWER SUPPLY

9
F/C (STEP)
RECALL(STORE)
AUTO(COMM)
INDEP
(PARA/SER)
OCP
(OVP RESET)
SHIFT
CONTRAST
OUTPUT
Data entry, Value outputENTER
AC Power Socket
Cooling Fan
Interface
8
POWER
DISPLAY
CH1 OUT
CH2 OUT
CH3 OUT
GND Terminal
Rotary Knob
V SET(CH1)
I SET(CH2)
OVP SET(CH3)
26262727
2828
2929
, “0”
Layout of Rear Panel
Function description as below:
Toggle main unit power on/off
Displays output voltage and current, power settings,
and volume, OVP, and OCP statuses
CH1 output terminals
CH2 output terminals
CH3 output terminals
Ground terminal connecting to CASE
Press and turn to incrementally adjust power settings;
turn to cycle through menus and setting
1
2
3
4
5
6
7
8
9
10
Set Output voltage;
[SHIFT] [CH1] to select Channel 1 settings
Set Output current:
[SHIFT] [CH2] to select Channel 2 settings
Set Over-voltage Protection value:
[SHIFT] [CH3] to select Channel 3 settings
FUNCTION LAYOUT FUNCTION LAYOUT
11
12
0~9
“.” , ENTER
Cooling Fan
USB communication interface
RS232C communication interface
AC power input terminal
Press to restore factory settings[SHIFT] [ ]
Turn on or off output; if a channel is selected,
you can turn on or off the corresponding channel;
when you select no channel, all channels on turned on or off.
Move the cursor upward by pressing [ ] in the storage settings
Move the cursor on the right by pressing [ ] in the storage settings
[SHIFT] [ ] to toggle the audible alert on or off.
to access the display contrast settings,
use the rotary knob to adjust; press [ENTER] to exit setting.
[SHIFT][CONTRAST]
Press first to access the second assigned function
of a button.
Turn OCP on or off;
[SHIFT][RESET] key to clear over-voltage protection
Switch to independent output mode;
[SHIFT][PARA/SER] to switch to Parallel or Serial output mode
Toggles automatic execute mode;
[SHIFT] [COMM] to access the interface
of the communication settings.
Recall the stored settings;
[SHIFT][STORE] to edit and save channel settings.
Change incremental tuning value of the rotary knob;
[SHIFT][Step] to change the incremental steps
of the rotary knob
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Move the cursor downward by pressing [ ] in the storage settings
Move the cursor on the left by pressing [ ] in the storage settings