Arduino替代程控电源专题方案.docx

POWER SUPPLY PROJECT
AGILENT 6612C (KEYSIGHT 6612C) POWER SUPPLY REPLACEMENT.

Feature 3
Key parts 4
OPA547T TO220 4
Arduino Mega-2560 5
Arduino Mega2560 extension board (shield) (mega2560 扩展板) 7
INA219 power monitor 8
LCD display i2C 10
to220散热片 10
Dc POWER SUPPLY 11
BOM 12
Schematic 13
OPAMP opa547 14
I_LIM Formula 14
Vout Formula: 15
Arduino Board connection 16
current limit calibration 17
wIRE sOLDERING 錯誤! 尚未定義書籤。
Calibration 23
Test equipment requirement: 23
Calibration procedure 23

FEATURE
SCPI command support
Interface: Com port (protocol: 9600N, 8,1 )
Voltage output: 0~9V
Current Output: 0~200mA ( max 500mA but need heat sinking solution)
Measurement capability:
Hight
+26V 1A
Low
16V, 400mA
Measure speed: <6mS, (AP command response time 65 mS )

KEY PARTS
OPA547T TO220
Shopping link ~= 28~38 RMB

High-voltage High-current OPAMP TO220

ARDUINO MEGA-2560
Shopping link ~=40 RMB

GPIO
Analog Measurement
DAC generate voltage to OPA548 ( 2KHz PWM n/1024 )
Voltage / Current control ( 2KHz PWM n/1024 )
RS-232 communication (9600, N, 8, 1 same as Keysight 6612c)
LCD display control. 16*2
MFG, Model name, version, information
Voltage / Current status
Dis / CV / CC information (disable output, control voltage, control current )

ARDUINO MEGA2560 EXTENSION BOARD (SHIELD) (MEGA2560 扩展板)
Shopping Link

INA219 POWER MONITOR
Measure current and voltage.

I2C interface.
Shopping Link ~=24 RMB

LCD DISPLAY I2C
I2C interface.

Shopping Link ~=12 RMB

TO220散热片
Shopping Link ~=0.5RMB

DC POWER SUPPLY
SPEC: 12V 2A

Shopping link ~= 30RMB

BOM
Arduino Mega2560 (40)………………………………………………………………………………..*1
Mega2560 extension board( shield) (10)………………………………………………..*1
OPA547T (30)………………………………………………………………………………..*1
INA219 (24) ………………………………………………………………………………..*1
Res 15K ohm …for low pass filter (1)……………………………………………………………………………..*2
Cap 10uF (15V) SMD ceramic for low pass filter (5)……………………………………….*5
1.5K 1% ( for gain control) (1)…………………….…………………………*2
to220散热片(1)………………………………………………………………….…………*1
LCD 顯示屏 (12) 1602 I2C 5V ……………………………..………………*1
12V / 2A DC power adaptor ………………………………………………………*1
USB 延長線 1m …………………………………………………………………………..*1
BOM total cost ~= 130
Label hour 2 pieces/1day ( soldering + calibration )

SCHEMATIC

Google DOC link to Chart

OPAMP OPA547

I_LIM FORMULA
Example:
I_LIM=0.500 (current limit 500mA )
ADC voltage will be à 4.75-31600*Ilim/5000 =1.59v
Command:
Curr:500mA
Curr:0.5

R1=R2=1K
Gain =1+R2/R1 =2
VOUT FORMULA:
Vout = Vin *2

ARDUINO BOARD CONNECTION
Arduino Mega 2560
Arduino Uno R3
DIGITAL PIN
0 Rx
1 Tx
2 PWM Output Vout Control, Connect to OPA 547 : V+
3 PWM Output Ilim control, Connect to OPA 547 : Ilim
4 INPUT PIN ( or force low to disable output )Connect to OPA 547 : E/S pin (Enable/ Status )
V_E/S HIGH (output enabled) E/S Pin Open or Forced HIGH (V–) >+2.4 V (working mode))
V_+E/S LOW (output disabled) E/S Pin Forced LOW (V–) <+0.8 V (Thermal Shutdown Status)
E/S pin Force low to disable output

CURRENT LIMIT CALIBRATION
I_lim=(Vbase-Vadc)*rate
X=Vbase
Y= rate
I_lim= (X- Vadc ) *Y
Set device:
Volt 2V
OUT 1
Debug:1
PWM:3: 714 ( expect around 200mA current limit.) record current by current meter. (I_200mA)
PWM:3 843 ( expect around 100mA current limit.) record current by current meter. (I_100mA)
Put equation in website
I_200mA=(x-714)*y , I_100mA=(x-843)*y
a= I200mA
Actual measurement current under 200mA setting
b= I100mA
Actual measurement current under 100mA setting
x=( 843*a-714*b)a-b
y=a-b( 843-714)
To get X and Y value.
Case 1:
I_200mA= 142mA
I_100mA=77.8mA
142=(x−714)y
77.8=(x−843)y
X=999.33, Y=0.4977
Put both value in FW code ADC_Base =X , Rate=Y

WIRE SOLDERING
PICTURES

USB EXTENSION CABLE

CALIBRATION
Calibration procedure implemented in GTS scrip file.
TEST EQUIPMENT REQUIREMENT:
1: voltage meter
2: current meter (range 0 ~200mA)
3 DUT (with external power plug 12V/ 2A)

CALIBRATION PROCEDURE
儀器準備:
電流表 0~200mA 電流表 ( 需要越精準越好)
步驟
l RUN scrip file. Maetay6612_calibration.xmz (需安裝 GTS )
l 先不掛上 電流表
l 程式會自動挑整電壓到 5V
l 按照批示 (Apply Current Meter) 掛上 電流表( 一端接地 一端接輸出 ) 使其輸出大電流進入電流保護 狀態
l 輸入電流表讀到旳電流值 (mA) 70~100 左右
l 輸入完 按 enter
l 再次 輸入電流表讀到旳電流值 (mA) 140~150 左右
l 輸入完 按 enter
l 再次 輸入電流表讀到旳電流值 (mA) 150 左右
l 輸入完 按 enter
l 拿開 電流表 (Remove Current Meter)
l 完毕校驗