DIY 4-Digit Red Digital Ammeter Kit ICL7107 DC 5V 35mA Ammeter DIY Soldering Kit

Product Introduction:

1.Model: AMM-TE
2.PCB Size: 70.6*39mm  
3.Display Window Size: 51*24mm
4.Operating Voltage: DC 5V
5.Operating Current: 35mA
6.Measurement Precision: +/-1mA
7.Measurement Range: 0-2A
8.Overrange Display: the first bit displays 1 or -1
9.Display Color: Red

Packing List:

Circuit Diagram:

Circuit Principle:

AMM-TE ammeter is mainly composed of ICL7107, power circuit, reference voltage source,
input circuit and display circuit.
▲1. ICL7107 is a BCD output integral type A/D conversion chip, its internal includes; linear amplification, analog switch, oscillation, display driving etc.
▲2. Power circuit is divided into positive power and negative power; positive power is input by J2,C8 filtering; negative is composed of R8,Q1,L1,C6,C7,D2,D3 and ZD1, and generate -5V voltage is input by chip 26th pin.
▲3. Reference voltage source is composed of R1,R2,VR1,R9 and U2; 36-pin is reference voltage input pin; adjust VR1 potentiometer to let 36-pin voltage be 100mV.
▲4. Input circuit is composed of J1,R5,R6 and C3. When the current of measured circuit passes through R5, it will generate a voltage on R5; this voltage will be input to chip 31-pin through R6 current limiting and be processed; C3 is input voltage filtering capacitor.
▲5. Display circuit is composed of DS1-DS4,D1,D4;4 digital tubes can be drived directly by the chip, R10 is current limiting resistance of DS1-DS3 digital tubes decimal points.

Finished Product Debugging:

1. After connecting with DC 5V (please notice the polarity), the digital tube will display -.000 or .000,this is normal.
2. Use multimeter to measure the voltage between chip 36-pin and 35-pin,and adjust VR1 potentiometer let it be 100mV

Key Points Voltage Reference Value:

1.Chip 1-pin and 21-pin voltage 5V
2.Chip 36-pin and 21-pin voltage 100mV
3.Chip 26-pin and 21-pin voltage -5V

I. Tested by ICStation's Outstanding Partner ELECTROJUANYU:

Learn More Details in the Video:
(The language in the video is Spanish)

II. Tested by ICStation's Outstanding Partner arduinoLab:

Learn More Details in the Video:
(The language in the video is Russian)

ICStation doesn't accept any form of pay on delivery. Items used to be shipped after payment. Below are the payment methods we can accept at the moment:

1) Paypal Payment

PayPal is a secure and trusted payment processing service that allows you to shop online. PayPal can be used at icstation.com to purchase items by Credit Card (Visa, MasterCard, Discover, and American Express), Debit Card , or E-check (i.e. using your regular Bank Account). 

We are PayPal Verified 

2)  Bank Transfer / Wire Transfer / T/T

Bank Transfer / Wire Transfer / T/T payment methods are accepted for orders which the total price is up to US$300. The bank will charge about US$50 for the transfer fee if we do the payment in these ways. Feel free to contact us for bank payment details if you need pay via bank.

For other payment method, please contact us at orders@icstation-team.com for more details.