ESSENTIAL INFORMATION
BUILD INSTRUCTIONS
CHECKING YOUR PCB & FAULT-FINDING
MECHANICAL DETAILS
HOW THE KIT WORKS
GENERATE A PLEASING AROMA WITH THIS
AIR FRESHENER KIT
Version 2.0
Air Freshener Essentials
www.kitronik.co.uk/2123
Build Instructions
Before you start, take a look at the Printed Circuit Board (PCB). The components go in the side with the writing on
and the solder goes on the side with the tracks and silver pads.
PLACE RESISTORS
1
Start with the two resistors:
The text on the PCB shows where R1 and R2 go.
Ensure that you put the resistors in the right place.
PCB Ref
R1
R2
Value
1M
1K
Colour Bands
Brown, black, green
Brown, black, red
2
SOLDER THE VARIABLE POTENTIOMETER
Solder the variable potentiometer into the PCB where it is labelled R3.
PLACE THE TRANSISTORS
3
Place the two transistors into the board where it is labelled Q1 and Q2. Make sure that the device
is the correct way around. The shape of the device should match the outline on the PCB.
PLACE THE CAPACITOR
4
Place the capacitor into the board where it is labelled C1. Make sure that the device is the correct
way around. The capacitor has a ‘-’ sign marked on it, which should match the same sign on the
PCB.
Using an electrolytic capacitor backwards could result in it being destroyed.
ATTACH THE BATTERY HOLDER
5
Attach the battery holder. Start by feeding the leads through the strain relief hole next to the power
connection. The wire should be fed in from the rear of the board.
The red lead should be soldered to the ‘+’ terminal (also marked with the text ‘red’) and the black lead
should be soldered to the ‘-’ terminal (also marked with the text ‘black’).
Air Freshener Essentials
www.kitronik.co.uk/2123
SOLDER THE MOTOR
6
Solder the motor to the board where it is marked ‘motor’. Again, use the strain relief and
make sure that the red and black wires go to the right place.
ATTACH THE RESET SWITCH
7
Attach the reset switch. First cut and strip two short lengths of the wire supplied. Solder one to
each of the two terminals on the switch. Then solder the other end to the PCB where it is marked
‘switch’. It does not matter which way around the two wires go.
Checking Your Air Freshener PCB
Check the following before you insert the batteries:
Check the bottom of the board to ensure that:
All holes (except the 4 large (3mm) holes in the corners) are filled with the lead of a component.
All these leads are soldered.
Pins next to each other are not soldered together.
Check the top of the board to ensure that:
The shape of the transistors match the outline on the PCB.
The ‘-’ on the capacitors match the same marks on the PCB.
The colour bands on R1 are brown, black & green.
The battery cage is connected to ‘POWER’ and that the red and black wires match the red and black
text on the PCB.
The motor is connected to ‘MOTOR’ and that the red and black wires match the red and black text on
the PCB.
Instructions
Insert the batteries.
When the start switch is pressed, the motor will spin.
The duration that the motor spins for can be adjusted with R3.
Air Freshener Essentials
www.kitronik.co.uk/2123
Fault finding flow chart
Start
Set the delay just off minimum
Power the board up
Check
The base & collector
on both transistors
Q1 & Q2 for shorts
Yes
Does
the motor
spin?
No
Press the switch
Yes - but only whilst
the switch is pressed
Does the
motor spin?
Yes
No
There is a dry
joint on C1
Yes
Is the
delay for the right
length?
No
Check
For dry joints on the motor, power
and both ends of the switch
connections.
For dry joints on Q1 & Q2
For shorts on Q1, Q2 & C1
Stop
Check
R2 / R3 for dry joints.
That R1 / R2 are in the right place
(R1 is brown, black, green)
Fault Finding
Air Freshener Essentials
www.kitronik.co.uk/2123
Designing the Enclosure
When you design the enclosure, you will need to consider:
The size of the PCB (below left).
Where the fan unit is mounted (right).
Where the start switch is mounted (bottom right).
Where the batteries will be housed (bottom left).
60 (Clearance)
Ø18
24 (Clearance)
Ø25
20
These technical drawings of the parts should help you to plan this.
All dimensions in mm.
Ø5
16
57
26
12
Ø8
Mounting the PCB to the
enclosure
The drawing to the left
shows how a hex spacer
can be used with two bolts
to fix the PCB to the
enclosure.
Your PCB has four
mounting holes designed to
take M3 bolts.
25