FK1221 Solderless Flasher with 4 LEDs


The FK1221 is a solder-less kit which introduces a flashing light circuit of 4 LEDs which alternately turns 2 sets of 2 LEDs  ON and OFF. The flashing rate can be adjusted by trimmer potentiometer.

9 in stock (can be backordered)


This kit is an Astable Multi-vibrator.   It  demonstrates the principle of how an oscillator works, and how it’s frequency can controlled.

No Soldering is required as the kit comes with sockets already installed and just needs the correct components to be inserted.

The FK1221 uses  4 LEDs  which flash ON and OFF alternately as 2  separate sets of 2 LEDs each.

The kit allows the user to adjust the flashing rate with the included trimmer potentiometer.


It lends itself to simple experimentation and changing Resistor or Capacitor component values to change the oscillator frequency and hence the rate of the flashing.


Construction Notes come with each kit.  The Notes include step-by-step graphics of the assembly process.

The student notes are aimed at allowing students to work at their own pace, and achieve a high probability of success.


Technical Specifications

– Power Supply : 9VDC

– Current Consumption : 18mA

– PCB dimensions : 51 x 38 mm.  ( 2 x 1.5 in.)


Additional information

Weight .1 kg
Dimensions 12 × 10 × 3 cm