Page 1
LED Adjustable Speed Flasher
Model GSK-109
This is an excellent kit for introducing basic electronic principles.
Two LED’s will alternatively blink and the blinking speed is
adjustable. Kit is easy to assemble with minimal components.
Technical Specifications
n Power Source: 9-12 VDC
n Consumption: 16-22 mA max.
n Adjust flashing speed with potentiometer
n PCB dimensions: 1.39 x 1.22 inches
Operating Principles
This is a two LED circuit that works alternatively through
transistor 1 and transistor 2 in the form of a multi-vibrator
frequency circuit. When TR1 is powered, LED1 will light and
LED2 is off. When TR2 is powered, LED2 will light and LED1
is off. Blinking speed is controlled by potentiometer VR1.
Circuit Assembly
Please refer to Figures 1, 2, and 3 for aid in component
placement. It is recommended to start with lower components
i.e. diodes, resisters, electrolyte capacitors, and transistors.
Be careful to check polarity with Figure 3 before soldering. If a
problem is detected it is best too use a desoldering pump or
desoldering braids to remove component. This will minimize
potential damage to the printed circuit board.
Figure 1 Installing components
Testing
Connect circuit to 9-12 VDC power source. LED1 and LED2
will work alternatively. Adjust blinking speed with VR1. If LED’s
do not light or blinking speed will not vary please review
Troubleshooting.
Troubleshooting
This circuit has only a few components. The main cause of
problems come from misplaced components or faulty soldering.
Utilize Figure 3 to ensure proper placement/polarity and
then check solder points for connectivity.
Accessories
Use GSB-17 (sold separately) to house the PCB and batteries.
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com
Page 2
Figure 2 LED flasher 2 dot circuit
Figure 3 Connecting circuits
GSK-109
Resistors
R1, R4 470 Ω yellow – violet – brown – gold
R2, R3 3 kΩ orange – orange – red – gold
Potentiometer
VR1 10 kΩ or 103
Electrolytic Capacitors
C1, C2 33 µF
Transistors
TR1, TR2 C458, C828, C945, C1815
Loading...