LOAD CELL AMPLIFIER BOARD
MODEL

ＬＡ－１０４１

OPERATION MANUALTOYO SOKKI CO.,LTD.
Head office: 964-24 Nippa-chou, Kouhoku-ku, Y o k o h a m a , 22 3 - 0 05 7 Ja p a n
ＴＥＬ +81-45-540-8353
ＦＡＸ +81-45-544-8354

MA4-00296-R0 (2020/11)

－－ Table of contents －－Page§ １ ． Su m m a r y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3§ ２ ． A p pe a r a n c e a n d E a c h n a m e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3§ ３ ． O pe r a t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
３－１）
３－２）
３－３）
３－４）
３－５）
３－６）
３－７）

S OLDERING JUMPER FOR SETTING EXCITATION VOLTAGE TO L OAD C ELL , JP2,3 ................... 4
S OLDERING JUMPER FOR SETTING AMPLIFICATION RANGE , JP1 ...................................... 4
S OLDERING JUMPER FOR SETTING A CUT OFF FREQUENCY OF FILTER , JP4,5 ....................... 4
ZERO ADJUSTMENT TRIMMER ........................................................................... 5
SPAN ADJUSTMENT TRIMMER ........................................................................... 5
RT (A DDITIONAL RESISTOR FOR INITIAL T ARE SUBTRACTION ) ...................................... 5
RZ (A DDITIONAL RESISTOR TO OFFSET THE OUTPUT VOLTAGE ) ..................................... 5§ ４ ． Ca li br a t io n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
４－１） C ALIBRATION METHOD WITH ACTUAL LOAD ............................................................ 6§ ５ ． Tr o u b le sh o o t i n g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
５－１）
５－２）
５－３）
５－４）

B ASIC CHECK POINT ..................................................................................... 6
W HAT TO DO IF THE DESIRED CALIBRATION IS NOT ACHIEVED ....................................... 6
J UDGEMENT WHETHER THIS UNIT IS MALFUNCTION ................................................... 7
C HECK L OAD C ELL ....................................................................................... 7§ ６ ． I n st a ll a t i o n a n d c o n n e c t io n m e t h o d . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
６－１） I NSTALLATION ENVIRONMENT , ETC . .................................................................... 8６－２） T ERMINAL CONNECTION ................................................................................. 8６－３） H OW TO CONNECT WIRES OF CABLE DIRECTLY ......................................................... 9§ ７ ． S pe c if ic a t i o n s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0
７－１）
７－２）
７－３）
７－４）
７－５）

P OWER SUPPLY PART FOR L OAD C ELL ................................................................ 10
A MPLIFIRE PART ........................................................................................ 10
G ENERAL ................................................................................................ 10I NCLUDED A CCESSORIES .............................................................................. 10
W ARRANTY ............................................................................................. 10§ ８ ． D im e n si o n a l Dr a w in g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1This document is translated from MA4-00221-R4 (Japanese)

MA4-00296-R0-2-

§１．Summary
This unit is a built-in board which amplifies a signal from a strain gauge transducer and can
output voltage signal 0～±5V ( maximum ±10V at specified condition).
This unit is consisted of input signal part, amplification part and power supply part fortransducers.
The power supplied voltage is DC24V and isolated from voltage output signal.
Excitation voltage to Load Cell is selected from 5V or 2.5V at jumper setting.

§２．Appearance and Each nameAppearance of this unit

④

① ②

③
⑪

⑤
⑥
⑦
⑧

⑨

⑩

① SPAN TRIMMER

Span adjustment trimmer (14 rotation)② ZERO TRIMMER

Zero adjustment trimmer (14 rotation)③ JP 1-1 to 4

Soldering jumper for setting amplification range④ JP2, 3

Soldering jumper for setting excitation voltage to Load Cell

⑤ JP4, 5

Soldering jumper for setting a cut off frequency of filter⑥ RT

Land for soldering additional resistor (setting Tare subtraction)⑦ RZ

Land for soldering additional resistor (setting offset)⑧ C

Common land for soldering RT or RZ⑨ CN1

Connector of power line and voltage output line.
There are lands on backside for soldering cables directly.

⑩ CN2

Connector of Load Cell line.
There are lands on backside for soldering cables directly.

⑪ MOUNTING HOLES

Holes 2-Φ3.2 for fixing this board to the attached hexagonal
post with M3 screw

MA4-00296-R0-3-

§３．Operation
This unit outputs up to ±5V. (Max.±10V depending on intensity of input signal from a sensor)
Recommend to use lead-free (Pb-free) solder because this unit is lead-free.

３－１） Soldering jumper for setting excitation voltage to Load Cell, JP2,3
Excitation voltage is 5V as standard, but 2.5V is available when soldering jumpe r JP2,3.
When 2.5V is set, amplification range should not be changed, but output voltage becomes
unstable slightly.
Solder jumper JP2,3 according to the following table.
Excitation voltage to
Load Cell
EXC = 5V
EXC =2.5V

Setting Jumper
JP2,3: Not solder (Open)JP2,3: Solder (Short)３－２） Soldering jumper for setting amplification range, JP1
By soldering an appropriate jumper, a small signal from Load Cell 0.3～2.2mV/V can beamplified to output 0 to ±5V. JP1-2 is soldered at the time of shipment. When a input signal
is out of this range(0.7～1.2mV/V), solder jumper according to the following table.
JP 1-1, 1-2, 1-3 or 1-4 should be soldered single, not multiple.
Se t t in g Ju m p e r
JP 1 - 1 t o 1 - 4
1-1 1-2 1-3 1-4

EXC=5V

EXC=2.5V

Spa n a m o u n t
to output 5V( m V /V )Amplification

Spa n a m o u n t
t o o u t p u t 10 V
( m V /V )

○

×

×

×

439～1047

878～2094

2.27～0.96

―― ―

×

○

×

×

730～1742

1460～3484

1.36～0.58

2.74～1.15

×

×

○

×

1065～2544

2130～5088

0.93～0.40

1.87～0.79

×

×

×

○

1752～4184

3504～8368

0.57～0.24

1.14～0.48〇 ： S o l de r 、 ×： N o t so ld e r３－３） Soldering jumper for setting a cut off frequency of filter, JP4,5
When an input signal from Load Cell fluctuates due to external vibration, set a cut off
frequency of filter to be lower and make the output voltage becomes less affected from thatfluctuation.
Solder JP4,5 according to the following table
Cut off frequency
fc = 100 Hz
fc = 2 Hz

Setting Jumper
JP4,5: Not solder (Open)JP4,5: Solder (Short)Noise level originated from amplifier itself at fc=2Hz decreases half compared to the one at
fc=100Hz. The measured value should be more stable.

MA4-00296-R0-4-３－４） ZERO adjustment trimmer
Unbalanced voltage of Load Cell or an equivalent voltage of Tare amount can be canceled tozero by adjusting ZERO trimmer (14 rotation).
If the output voltage cannot be adjusted to be zero, additional resistor, RT or RZ is required
to mount.
３－５） SPAN adjustment trimmer
This is a span adjustment trimmer (14 rotation) to set the output voltage to the desired level.
If the output voltage cannot be adjusted to the desired level, change the amplification range
by soldering jumper, JP1. Refer to 3-2)
３－６） RT (Additional resistor for initial Tare subtraction)
When an equivalent voltage of Tare amount is so large that the output voltage cannot be
adjusted to be zero, mount an additional resist or RT to cancel it. Output voltage decreases
toward minus.
When a resistor value of RT is small, cancellation of Tare amount is larger. Select anappropriate resistor value according to the following table. Use a metal film resistor withtemperature coefficient 50ppm/℃ or less.
Cancellation of
Tare amount
0.2mV/V
0.4mV/V
0.6mV/V
0.8mV/V
1.0mV/V

Required resistor value, RT
Load Cell 350Ωtype
Load Cell 700Ωtype
about 430kΩ
about 910k Ω
about 220k Ω
about 430k Ω
about 150k Ω
about 300k Ω
about 110k Ω
about 220k Ω
about 91kΩabout 180k Ω３－７） RZ (Additional resistor to offset the output voltage )If there is an offset level of output voltage toward minus and output voltage cannot be
adjusted to be zero, mount an additional resistor RZ to increase the output voltage tocancel the offset level. This operates as an opposite role of RT. Select an appropriate
resistor value according to the above table 3 -6). Use a metal film resistor withtemperature coefficient 50ppm /℃ or less.

MA4-00296-R0-5-

§４．Calibration
Calibration is done by two steps. One is that set the output voltage to zero when no load
is applied. Two is that set the desired output voltage when an object is loaded , which isoperated by actual load calibration using a reference weight as an actual load.
When this unit and Load Cell are c ombined to ship from TOYO, c alibration has been done
at our factory.
４－１） Calibration method with actual load1). Put nothing on Load Cell (only the initial Tare load is applied).
2). Turn a ZERO trimmer to adjust the output voltage to 0V.
3). Place a weight such as a reference weight on Load Cell and turn a SPAN trimmer toadjust the output voltage to the relevant value of the weight.
4). Remove a weight such as a reference weight from Load Cell.
5). Confirm that the output voltage is 0V. If not, repeat from step 2) above.
If calibration cannot be done properly, refer to section §5 Troubleshooting and takemeasures to solve a problem.

§５．Troubleshooting
If this unit is malfunctioning, please contac t us if the problem cannot be solved by thefollowing measures. At this time, please inform us of the model name, product serial number,the malfunction symptoms and usage as much as possible. The model name of Load Cell or
sensor connected to this unit should be also informed.
５－１） Basic check point
1). Check whether the power supplied voltage DC24V is normal and stable2). Check whether the terminals are connected correctly and firmly５－２） What to do if the desired calibration is not achieved1). Zero adjustment cannot be done.
Zero adjustment range is ±15% against rated output voltage
If the output is more than 0V even if ZERO trimmer is turned fully counterclockwise(CCW), mount an additional resistor, RT, to de crease the output voltage.
If the output is less than 0V even if ZERO trimmer is tuned fully clockwise (CW), mountan additional resistor, RZ, to increase the output voltage .
2). When span adjustment, the desired output voltage cannot be set.
If the output goes below the desired value even if SPAN trimmer is turned fully clockwise(CW), solder JP-1 to increase the amplification by one step.
If the output exceeds the desired value even if SPAN trimmer is turned fully
counterclockwise (CCW), solder JP-1 to decrease the amplification by one step.
4 steps can be set according to JP-1 jumper setting. If the desired output is not obtainedeven if all the JP-1 jumper setting has been done, check whether Load Cell output satisfies
the sensitivity adjustment range of this unit.
The sensitivity adjustment range of this unit is -2.2mV/V to 2.2mV/V.
MA4-00296-R0-6-

Signal from Load Cell, 0.3 to 2.2mV/V is required to output 0 to 5V. Output 10V is possible
when a signal from Load Cell is more than 0.6mV/V
3). Output voltage is out of range of ±5V even though it is not overloaded.
① When a part of Load Cell cable is disconnected. (Refer: Section 5-4)
② Additional resistor RT, RZ is inappropriate. (Refer: Section 3-6)
③ When Load Cell becomes defective. (Refer: Section 5-4)５－３） Judgement whether this unit is malfunction1). Check the excitation voltage of Load Cell
Check whether the excitation voltage between #1 (+EXC) and #2 (−EXC) of CN2 is stable
at 5V±0.25V (2.5V±0.13V). If it is not stable, a power supply circuit inside this unit may
be defective.
2). Short the output voltage of Load Cell (making an electric short between terminal #3(+SIG) and #4 (−SIG)). In other words, the input voltage to this unit is made zero.
In this state, the voltage which adjusted by ZERO trimmer is output, so the output does
not become 0V, but it can be checked whether the output is stable.
If it is not stable, an amplification circuit in this unit may be defective. If it is stable, check
Load Cell side.
５－４） Check Load Cell
Since Load Cell is composed of a bridge circuit, it is possible to make a rough judgement
by measuring the input / output resistance and insula tion resistance.
＊ Please be sure to turn power OFF of this unit before checking Load Cell.
1). Failure judgement method by Load Cell resistance value.
① Remove all Load Cell cables.
② Measure the bridge resistance of Load Cell with a tester and check if there is any
abnormality in the input / output resistance.
2). Failure judgement method based on Load Cell insulation resistance① Remove all Load Cell cables.
② Measure the insulation resistance between shield and each cable of Load Cell at a
voltage within 50V.
In addition, the insulation resistance between a metal case of Load Cell and each cable
other than shield is also measured at a voltage within 50V .
③ If the insulation resistance is 1000MΩ or more, Load Cell is mostly good

MA4-00296-R0-7-

§６．Installation and connection method６－１） Installation environment, etc.
1)
2)
3)

The operating temperature range of this board is 0 ℃ to 40℃.
Consider installing in a place not exposed to the direct sunlight.
This board is operated with power supplied voltage DC24V±10%.
Note that connecting to a different voltage may cause failure or damage.
Fix this board with holes 2-Φ3.2 using attached hexagonal posts or M3 screw

６－２） Terminal connection
The shield line of each cable shall be grounded by either this unit or each connected
instrument, so that there is no ground loop.
1). Power line and output voltage cable connection (CN1)
Connector: B05B-XASK-1 (JST)No.
Connection signal
1

OUT+

Output voltage (+)

2

OUT－

Output voltage (－)

3

E

4

+24V

5

0V

Grounding (Earth)Power supplied voltage (DC+24V)
Power supplied voltage (DC0V)※#3(E) is connected to one of the fixing holes 2-Φ3.2 inside※Signal between #2(OUT-) and #5(0V) is isolated. Make them apart when wiring .
※When wiring a cable of output voltage, use a shield ed cable and terminate a shield at
the connected unit side.
2). Load Cell cable connection (CN2)
Connector: B5B-PH-K-S (JST)No.
Connection signal
1
Excitation
voltageto Load Cell (+)
EXC+
2

EXC－

Excitation voltage to Load Cell ( －)

3

SIG+

Input signal from Load Cell (+)

4

SIG－

Input signal from Load Cell (－)

5

SHL

Shield line of Load Cell cable※There are lands on backside of this board to solder each wires of cable directly, instead ofuse of connector CN1 and CN2

MA4-00296-R0-8-

６－３） How to connect wires of cable directly

Load Cell

Solder here

Ｖ

Backside of a board

DC24
V

Wiring as short
as possible

Shield of this cable should begrounded at connected unit side

MA4-00296-R0-9-

§７．Specifications

７－１） Power supply part for Load Cell
1). Excitation Voltage

DC5V±5％ as standard
DC2.5V±5％ is available when soldering jumper, JP2,3

2). Output current

22mA maximum
able to connect one Load Cell 350Ω type when EXC=5V,
one Load Cell 350Ω/120Ω type when EXC=2.5V.

７－２） Amplifire part1). Zero adjustment

Range ±15% against rated output voltage, Max. 5V
Multi-turn trimmer adjustment, 14 rotations

2). Sensitivity
adjustment

Span of input voltage 0.3 to 2.2mV/V can output 0 to 5V
by 14 rotations trimmer and soldering jumper of range , JP1
RANGE-1: 1.1 to 2.2mV/V
RANGE-2: 0.7 to 1.2mV/V (at the time of shipment )RANGE-3: 0.45 to 0.8mV/V
RANGE-4: 0.3 to 0.5mV/V
Standard sensitivity : Output 0 to 5V when EXC=5V,
0 to 1mV/V input, Gain=1000

3). Output signal

0 to 5V voltage signal, (Load resistance 2k Ω or more)
For span of 0.6mV/V or more, output of 0 to +10V is possible.

4). Non linearity±0.1％FS

5). Cut-off frequency

approx. 100Hz (-3dB)
2Hz (-3dB) is available when soldering jumper, JP4,5

6). Temperature coefficientZero±0.01％ FS/℃ typ. (standard sensitivity )(twice the above at EXC=2.5V)

Sensitivity±0.01％ FS/℃ typ.

７－３） General1)． Power stability±0.05％ FS (Power supplied voltage fluctuation within ±10％)2)． Power supplied voltage
DC24V±10％3)． Current consumption
100mA typ.
4)． Operating Temp./Humidity
0～＋40℃、20～85％ R.H. (without condensation)5)． Mass
approx. 30g
6)． Mounting method
Fix by using holes 2-Φ3.2 of this board
７－４） Included Accessories
1). Cable with connector for connecting power line and ou tput line2). Cable with connector for connecting Load Cell
3). Operation Manual

1 pc
1 pc
1 copy７－５） WarrantyThis board is covered by one year warranty against TOYO’s manufacturing or design fault.
(The board is taken over and repaired)MA4-00296-R0- 10 -

§８．Dimensional Drawing
Span adjustment trimmer
Zero adjustment trimmer

Connector of power line
and voltage output line

Connector of
Load Cell line

Parts mounting area

PH connector(2mm pitch)

XA connector(2.5mm pitch)

Recommend to use a shielded cablewhen extending

Cable with connector
Solder pad

Connector of Load Cell

Board of converting
cable

Connector of power line and output

Hole of binding band

Load Cell cable
Shield of cable (solder)(Option)

MA4-00296-R0- 11 -