Abra AK-330 User manual

Alcohol Vapor Detector D.I.Y Kit
for detecting alcohol vapor in household or workplace
environment using the MQ3 sensor
Part Number: AK-330
Level: Intermediate

2
Description:
This kit contains the required components to build yourself an alcohol vapor detector.
This module is based on an NE555 I.C. and an MQ3 sensor.
While being a simple soldering project for beginners, this kit can be used in a variety
of small personal, educational or enterprise applications.
This alcohol sensor is suitable for detecting alcohol concentration on your breath, just
like your common breathalyzer. It has a high sensitivity and fast response time. The
MQ3 sensor provides an analog resistive output based on alcohol concentration. The
drive circuit is also very simple.
This is a D.I.Y. kit that requires soldering through-hole components on the main
double-sided printed circuit board (PCB). Users with minimal soldering tools and
intermediate skills can easily assemble this module. The assembly process should
take anywhere between 10 to 20 minutes.
Specification:
Module
•Required Input Voltage: 5VDC
•Current: ≈ 150mA
•PCB Dimensions: 63 x 37 x 1.4mm (2.48”x 1.46" x 0.05”)
Sensor MQ3
•Environment Condition: -10°C~50°C
•Sensing Parameter: 0.05 - 10mg/L Alcohol
•Concentration slope rate: ≤ 0.6

3
Component
Label
Value / Type / Label
Quantity
Resistors
R1, R2
1KΩ / (Brown, Black, Black, Brown)
2
R3
120Ω / (Brown, Red, Black, Black)
1
R4
5.1Ω / (Green, Brown, Black, Silver)
1
RW
10KΩ Potentiometer
1
Light Emitting Diode
D1
5mm Red
1
D2
5mm Green
1
Zener Diode
D3
1N4148
1
Relay
JK
HK23F-DC5V-SHG Subminiature High Power Relay
1
IC Chips and Sockets
U1
NE555
1
----
DIP8 socket
1
Switches and
Connectors
S1
Single Row, Double Throw
1
J1
2.1mm DC Barrel Female Connector
1
PCB
----
Tin Plated, Green Soldermask, White Silkscreen
1
Modules
MQ-3
MQ3 Sensor
1
B1
Buzzer
1
Bill of Materials:
This package includes 16 pieces which are listed below along with their labels and quantity.

4
Assembly:
1) In order to assemble the module, you need the following tools:
*It is recommended to have some isopropyl alcohol and a fine soldering brush
handy to clean off the excess flux on the circuit board when the soldering is
done.
*ATTENTION* DO NOT USE RUBBING ALCOHOL, IT WILL DAMAGE THE COMPONENTS.
2) Open the package and verify the components. (refer to section 4. Bill of
Materials on page 3)
3) Lay down all the components on your workbench and proceed to the next step.
4) Prepare your soldering tools.
a) Use an appropriate tip for the application. Also, make sure the
soldering tip is clean. Gently use a brass wool or a brush to clean the
tip when needed. Another way of cleaning the soldering tip is to use a
wet sponge.

5
b) The soldering iron temperature depends on the type of solder used.
If you are using a typical 60/40 lead solder, depending on the thickness
the temperature should be set anywhere between 370 to 500 °F (187 to
260 °C). If you are using a lead-free solder, increase above temperatures
by 40 to 70 °F (5 to 20 °C).
*ATTENTION* HIGHER TEMPERATURES WILL DAMAGE THE COMPONENTS ALONG
WITH THE CIRCUIT BOARD.
*ATTENTION*DO NOT TOUCH THE SOLDERING IRON WHEN IT IS HOT.
c) It is recommended that you clean the board with a fine brush, isopropyl
alcohol and lint-free cloth to get rid of any pre-existing residue, glue or dirt.
This way the solder will create a better joint with the copper surface.
d) Have your flush cutter, needle nose plier or tweezers handy.
e) Having a roll of paper tape helps you to keep the components in place
when soldering on the bottom side of the board.
f) Have a rosin flux pen or paste handy. Adding flux to the pads before
soldering the components makes the wetting process easier by letting the
melted solder to flow better on the pad and create a better joint.
*ATTENTION* SOLDERING SHOULD BE DONE IN A VENTILATED AREA.
BREATHING SOLDER FUMES WILL HARM YOU.
g) Always cut the excess leads with a flush cutter once a component is
soldered on the PCB. At least 1mm of the lead should stick out from the
solder joints.

6
You may proceed to solder the
resistors in place by following
the labels on the board and
placing the correct color
resistor indicated in the “Bill of
Materials” section on page 3.
All soldering will be done on
the backside of the board.
Insert the 8 pin (DIP8) IC
socket as shown in the photo.
Once it’s soldered onto the
PCB, gently insert the NE555
chip onto the socket.
Ensure the notch of the
Integrated Circuit aligns with
the markings on the board,
also known as the silkscreen.
Solder the relay, the 10K
potentiometer and the buzzer.
Make sure the (+) of the
buzzer is facing the correct
way.
It is recommended to solder and cut of the excess lead with a flush cutter, one
component at a time.

7
Insert the switch, DC connector
and the MQ3 sensor as shown
in the picture and solder them.
Insert the 5mm LEDs as shown
in the image. Ensure that the
orientation of the LED is
correct.

8
Implementation:
This module should be powered up by connecting a 5V 1A DC power supply to
the J1 connector. This device has an onboard high power relay rated to 24VDC
2A; therefore, you can connect any peripheral device that you desire to the
output of the relay so it can be turned ON and OFF during the operation of the
sensor module.
The device is designed to work standalone where, when alcohol vapor or ethanol
is detected by the MQ3, the buzzer will be triggered to inform you that alcohol
has been detected. At the same time the relay will turn OFF. You may use the
potentiometer RW to adjust the sensitivity of the detector.

9
Related D.I.Y Kits:
AK-30 D.I.Y MINI Speaker Educational Kit
Acrylic Frame that requires assembly and a controller
board that requires some soldering work to get up and
running.
The provided audio boards come with LED Vu Meter to
see the sound level.
PI-ZEROWH-KIT Raspberry Pi Zero W
Basic Kit
A low-cost method of getting into Linux
environment and providing some pinouts to
interface with some sensors.
Excellent to learn programming using scratch,
OpenCV projects using python script language
or running a 3D printer server using Octo-print.
EK-1 Theremin Player Kit
A soldering based kit that works as a Theremin
when completed. The sounds coming out of the
speaker will vary depending on the closeness of
the fingers to the photocell sensor.
- Check out more awesome projects at www.abra-electronics.com -