Learn to solder kit - Flashing LED

This learn to solder kit is a fun little project for someone wanting to work on their soldering skills.

Follow along with the video  and you will make a little board that the lights flash across and the speed of the flashing can be changed by turning the pot.

Feature:

The Kit does not include a power supply.  It needs an input of 3-5v.  We use the battery pack here

Power supply voltage: 3-5V
PCB Size: 88 x 25mm
This kit is not included instruction.

How it works:
This kit is made up main circuit and decimal counter circuit, from the core of the self-excited NE555 multivibrator power through R2, R3, R4 charge the capacitor C1, C1 started when charging , NE555 2 feet still in low, so the output pin 3 goes high when power through R2, R3, R4 to charge C1 to 2/3 of the supply voltage , the output pin 3 level from high to low , NE555 conducting internal discharge , capacitor C1 through R4, R3, NE555 7 feet discharge until the voltage across C1 is less than 1 /3 of the supply voltage , NE555 and 3 feet level from low to high . C1 and charge again this cycle oscillations formed . Charging time : 0.695 (R2 + R3 + R4) C1, discharge time : 0.695 (R4 + R3) C1, R4 can be adjusted to control the output frequency of the oscillator , the oscillation clock signal is applied continuously NE555 CD4017 14 feet , the output terminal 10 is connected with the CD4017 10 LED, when the output terminal 10 turns CD4017 generated clock signal is applied at a high level , the D1 - D10 are sequentially lit to form a water -light effect .
You can adjust the flow rate adjustment R4 LED lights .