Transcript Step-by-step plan of PCB assembly

MOOD LIGHT PCB ASSEMBLY
V.2.2 - By Phil Townshend 2008
ASSEMBLING THE PCB
Hold up the PCB as shown below – try to locate the holes shown
RESISTORS
The first component is a resistor value 1Kohm, (brown, black, red).
It is not important which way round it goes.
RESISTORS
The next 2 resistors are 22 ohms, (red, red, black).
RESISTORS
The last 2 resistors are both 47 ohms, (yellow, violet, black).
IC HOLDER
Insert the IC holder with the notch at the top as shown below.
CAPACITOR
The first capacitor is 100nF in value (104 written on it). It
can be inserted either way round.
CAPACITOR
C2 must be inserted the correct way round. The longer lead is the positive
one. Insert into the top hole with the silver stripe downwards.
Positive
Longer
Leg
MULTICOLOUR LEDs
Flat side
D1 must be inserted with the flat section on the rim facing right.
This is normally the red/blue type. Insert them most of the way into the PCB.
MULTICOLOUR LEDs
D2 must be inserted the same way – this is the red/green type. You can put
either LED in either place, it just means the colours cycle in reverse.
FUNCTION SWITCH
Strip about 8-10mm of insulation from a 100mm of wire and twist the strands
together. Make another, then insert them into the PCB and solder.
Feed the wires
back through the
PCB as shown to
prevent them
breaking.
POWER LEADS
Connect a single red wire about 150mm long to the top hole and solder. Feed the black
wire from the battery clip, UP through the large hole first, then solder.
SWITCHES
There are 2 switches – the toggle switch for power and the push-to-make
switch for the function. Connect as shown below.
INTEGRATED CIRCUIT
Finally insert the IC making sure the notch is at the top.
Try not to bend the pins and ensure they are all inserted correctly.
ASSEMBLY NOTES
Both LEDs should light up red to start with. If they are green or blue, then the flat rim is
facing the wrong way and colours will not be displayed correctly. The LED should be
unsoldered using a de-solder pump, or by carefully heating up all 3 pads at once. Then
rotated 180º and re-soldered. Clear the holes before inserting them. Another way to
identify the orientation of the LEDs is that the shortest leg faces left.
Common faults are pads shorted with solder bridges. Carefully use an iron or de-solder
pump to clear them.
If only one LED comes on and stays on, the IC is the wrong way round. Disconnect power
immediately and insert the IC correctly.
The maximum voltage the circuit can handle is 5v. After this outputs on the IC start to
struggle and above 6v will destroy the IC completely.