Abra LED FLASHER KIT User manual

LED
FLASHER
BUILD YOUR OWN LED FLASHER
• Idealprojectfor
introducingbeginnerstoelectronics.
• Easytoassemblewithsilk-screened
componentlayoutonPCB.
• Providespracticeinsolderingtechnique.
• ImpressivedisplaywithtwoUltraBright
waterclearredLED’s.
• Adjustableashingrateforeffect.
• Batteryoperatedfor
safety.

Tools Required: •Soldering Iron •Solder •Diagonal Cutters •9V Battery
Kit Description:
e LED FLASHER KIT alternately ashes two red LEDs.
e ashing rate can be adjusted by varying the resistance of the P1 potentiom-
eter. Timing is provided by the popular 555 integrated circuit.
e 555 timer produces square wave pulses with a frequency that is determined
by the combination of the R1, R2, P1 and C1 values.
Circuit Description:
e circuit is composed of a 555 timer IC which creates square pulses, alternat-
ing between a HIGH and LOW state at pin3. e pulses ash LED1 and LED2.
e frequency of the square pulses are controlled by a time constant deter-
mined by the C1 capacitor, the R1, R2 resistors and the resistance of the P1
potentiometer.
General Assembly Guidelines:
Good soldering technique is the most important factor in successfully assem-
bling your kit.
A small pencil type soldering iron 25-40 Watts is recommended.
e tip of the iron should be kept clean at all times by wiping it oen on damp
sponge or cloth.
Touch the component leadandthesolderpad junctionwiththe solderingirontip.
Apply solder to the junction. It should not take more than 1-2 seconds for the
solder to melt.
A good solder joint will appear shiny and conform to the lead.
Refer to the ABRA website at www.abra-electronics.com using the part number
if you cannot identify a part in the part list.
Parts list:
Item ABRA Part# Description Quantity
IC1 LM555 Single Timer IC 1
SOCKET 8LP Dip Socket for LM555 Timer IC 1
LED1,LED2 LED-5CR Clear Red Diused LED 2
R1, R2 R1/4-10k 10k Ohm Resistor (Brown, Black, Orange) 2
R3, R4 R1/4-220 220 Ohm Resistor (Red, Red, Brown) 2
P1 3386P-1-104 100k Ohm Potentiometer 1
C1 10R16 10uF Polarized Capacitor 1
9V CLIP 29-130 9V Battery Clip 1
PCB LED-Blinky-B LED Flasher Kit PCB 1

Assembly step by step:
1. Install Resistors R1, R2, R3 and R4 as shown in the PCB Board Layout using
their color codes to identify them. e leads can go in either way.
Solder the resistors in place and trim the leads with the diagonal cutters.
2. Install Capacitor C1 as shown on the PCB Layout. C1 is a polarized capacitor
and must be placed with its shorter lead, indicating the negative side in the
hole marked with a minus sign. e white line on the side of the capacitor also
indicates the negative side. Solder C1 in place and trim the leads
3. Install the Potentiometer P1 as shown. Solder P1 in place and trim the leads.
4. Install LED1 and LED2 with their short lead in the hole with the minus sign.
e short lead is the cathode side. Solder the LEDs in place and trim the leads.
5. Install the socket for the LM555 timer IC with the small notch as shown in the
PCB Board Layout. Solder the socket pins in place.
Install the LM555 timer on the dip socket with the notches on the LM555 and
the socket on the same side.
6. To install the 9V battery clip, rst pass the wires from the bottom side through
the holes adjacent to the battery solder pads and then into the solder pads.
Connect thered wireto the + andthe black wire to the –connectiononthe board
Solder the wires in place.
7. Before connecting the battery to the circuit, review your work as per the As-
sembly Check out.
PCB Layout
Schematics

Assembly Check out:
• It is highly recommended to inspect the PCB carefully.
• Check for proper placement of components.
• Check that capacitor C1, IC1, & both LEDs are installed in the correct direction.
• Check that all connections are soldered with a shiny appearance.
• Redo any solder connection that is dull looking or in a ball.
• Check that there are no solder bridges touching adjacent connections together.
Solder Proles:
Operation:
Connect the 9 Volt battery to the battery clip.
With a small at screwdriver adjust the potentiometer until you can see both LED
lights ash alternatively.
You can vary both LED’s alternately ashing rate or have just one LED constantly on.
Troubleshooting:
• Turn the potentiometer w/ a small screwdriver to see both LED ash alternately.
• If one of the LEDs do not light up then probably its polarity was reversed.
• Unsolder the LED and solder it the other way around.
• Verify that the 555 timer IC was installed with its notch facing down as per the
PCB Board Layout.
• Verify if that the resistors values are correctly placed.
• e R1 and R2 resistors should be 10k.
• Verify that C1 capacitor polarity is correct.
• Replace the 9V battery if the circuit has been functioning and then stops.
www.abra-electronics.com U.STollFree:1-800-717-2272
[email protected] Can.TollFree:1-800-361-5237
MADE IN CANADA