#809 Ring Counter SMD Practice Board

A full-featured soldering practice board with a wide range of components from 0402 to 1206 and SOP-8/16. It includes a classic 4017/555 ring counter test circuit.

Build

Here’s a quick demo..

Notes

NB: see LEAP#171 SMD Practice Boards for an overview of all the SMD practice boards I have tried.

This is an example of a pretty full-featured practice board with a wide range of components from 0402 to 1206 and SOP-8/16.

central feature is a classic 4017/555 ring counter test circuit - similar to the LEAP#107 Ring Counter project
all components are laid out in circuits with clear test points

Originally purchased “SMD components welding practice board / Welding practice light kit/ Skills Training welding competition kit” (seller listing on aliexpress) for US$12.70 for 5 boards (US$2.54/board) in May-2015. That seller is no longer offering the item, but an equivalent item is available (as of Dec-2025) for SGD$2.42: “DIY SMD SMT Welding Practice Soldering Skill Training Board 3-12V Water Flowing Led DIY Kit for School Learning Project” (seller listing on aliexpress)

Kit Details

kit-parts

See instructions (Chinese PDF).

In translation:

Product description

The Super SMT All-Surface Mount Soldering Practice Board Kit is a product specifically developed for spot checks on electronic assembly and debugging skills. Most current electronic products use surface mount components, and successfully assembling a product requires practice. This soldering kit consists of components for the NE555+CD4017 LED flashing circuit and surface mount practice components. The NE555+CD4017 LED flashing circuit design uses the widely used NE555 chip in digital circuits to form an oscillator, and controls the LED blinking through the CD4017’s counting output. It is a valuable product for learning and circuit analysis.

Introduction to simple principles

The NE555+CD4017 flowing light circuit consists of an oscillator formed by a monostable circuit based on the NE555 and a 14-stage binary serial counter. The oscillator frequency is determined by C27 and resistors R48 and R49, with a frequency of F = 1.44/(R48 + 2R49) × C27. The oscillation pulse is output from pin 3 of the NE555 as the counting pulse for the CD4017. Pin 14 (CLK) of the CD4017 is connected to the clock signal output from pin 3 of the NE555. Pins 15, 13, and 8 are grounded. Ten LEDs (D2-D11) are connected externally through ten current-limiting resistors to Y0~Y9, arranged in a circle. When the circuit is powered on, Y0~Y9 output high levels sequentially, causing the LEDs to light up sequentially, forming a flowing light ring.

Component list for NE555+CD4017 running light circuit

Item	Name	Specification	Ref	Package	Qty
1	capacitor	0.1µF	C27, C28	0805	2
2	LED	red	D1-D11	0805	11
3	LED	blue or green	D16-D19	0805	4
4	diode	1N4148	D12-D15	LL34	4
5	transistor	S8050	Q1-Q4	SOT-23	4
6	resistor	10kΩ	R48, R61-R64	0805	5
7	resistor	2MΩ	R49	0805	1
8	resistor	470Ω	R50-R60, R65-R68	0805	15
9	IC	NE555	U1	SO-8	1
10	IC	CD4017	U2	SO-16	1

Component list for surface mount practice section

Item	Name	Specification	Ref	Package	Qty
1	resistor	random	1206R	1206	10
2	capacitor	random	0805C	0805	12
3	resistor	random	0603R	0603	22
4	resistor array	random	0603P	0603*4	6
5	capacitor	random	0603C	0603	22
6	resistor	random	0805R	0805	12
7	resistor	random	0402R	0402	24

Circuit Design

schematic

Here’s a quick video of the test circuit in action:

Credits and References

LEAP#171 SMD Practice Boards
“SMD components welding practice board / Welding practice light kit/ Skills Training welding competition kit” (seller listing on aliexpress) - as originally purchased
“DIY SMD SMT Welding Practice Soldering Skill Training Board 3-12V Water Flowing Led DIY Kit for School Learning Project” (seller listing on aliexpress) - similar kit, another seller
LEAP#107 Ring Counter

Project Notes