Welding practice board includes PTH components and surface mount packages (SMD) of common basic components such as resistors, capacitors, transistors, mosfet, diodes and inductors. After welding the components that need to be welded (to start the circuit function), the board can achieve the effects of running lights and breathing lights. The board provides 0805/0603/0402/0201/01005 and other packages for advanced challenges, comprehensively assessing the welding skills of the welder.
After power on, slide the switch to the side near the Type-C end (ON). The DIP switch from left to right controls the on and off of the straight-through running lights. The rightmost switch controls the on and off of the 24 LEDs in the upper right corner for the breathing light effect. The effects of running lights and breathing lights are controlled by tapping the button. When the button is not pressed, the gate (G) of the Mosfet is pulled to a low level by a 100KΩ pull-down resistor, keeping the gate of the Mosfet in a stable low-level initial state to prevent external interference and ensure a stable state. The Mosfet is conducting, and the LED is controlled by the DIP switch. When the button is pressed, the gate of the Mosfet is at a high level, the Mosfet is cut off and not conducting, and the running light or breathing light effect of the LED starts. The priority of the button is higher than that of the DIP switch. The role of the Schottky diode is to prevent current backflow.
See also the SMD only version:
SMD soldering training PCB functional circuits
Schematic Welding practice board PTH and SMD
Running light circuit
The running light effect is achieved using an NE555 timer to construct a multivibrator driving a CD4017 decimal counter.
Breathing light circuit
The breathing light effect is achieved using an LM358 operational amplifier and peripheral circuitry to construct a triangle wave signal generator.
BOM Welding practice board PTH and SMD
| Parts | Value | Description | Quantity |
| Resistors | |||
| R1,R2,R3,R4,R5,R6,R7 | 1kΩ (102) | RES-TH 1/4W | 7 |
| R8,R14,R15 | 100kΩ (104) | R0805 – SMD resistor | 3 |
| R9,R10 | 10kΩ (103) | R0805 – SMD resistor | 2 |
| R11,R12,R13 | 47kΩ (473) | R0805 – SMD resistor | 3 |
| R16 | 100Ω (101) | R0805 – SMD resistor | 1 |
| R17 | 01005 | R01005 – SMD resistor | 1 |
| R18 | 0201 | R0201 – SMD resistor | 1 |
| R19 | 0402 | R0402 – SMD resistor | 1 |
| R20 | 0603 | R0603 – SMD resistor | 1 |
| R21 | 0805 | R0805 – SMD resistor | 1 |
| RP1,RP2 | 50kΩ (503) | 3362P trimpot | 2 |
| Capacitors | |||
| C1,C2 | 10uF | Aluminum Electrolytic capacitor | 2 |
| C3,C4 | 100nF | Ceramic capacitor | 2 |
| C5 | 1uF | SMD ceramic capacitor 0805 | 1 |
| C6,C8 | 10uF | SMD ceramic capacitor 0805 | 2 |
| C7,C9 | 100nF | SMD ceramic capacitor 0805 | 2 |
| C10 | 47uF | SMD ceramic capacitor 0805 | 1 |
| C11 | 10uF | SMD Aluminum Electrolytic Capacitor | 1 |
| C12,C13 | 10uF | CASE-A-3216-18 Tantalum Capacitor | 2 |
| Semiconductors | |||
| D1,D2,D3,D4,D5,D6,D7 | 1N5817 | DO-41 Schottky Diode | 7 |
| D8,D9,D10,D11,D12,D13,D14,D22 | SS34 | SMA(DO-214AC) Schottky Diode | 8 |
| LED1,LED2,LED3,LED4,LED5,LED6,LED7 | 204-10SURD/S530-A3-L | 3mm LED RED | 7 |
| LED8,LED9,LED10,LED11,LED12,LED13, LED14,LED15,LED16,LED17,LED18,LED19, LED20,LED21,LED22,LED23,LED24,LED25, LED26,LED27,LED28,LED29,LED30,LED31 |
KT-0805G | LED0805 RED LED | 24 |
| Q1,Q2 | SS8050-TA | NPN transistor TO-92-3 | 2 |
| Q3 | FSS2301M | P-Channel SOT-23 MOSFET | 1 |
| Q4 | SS8050 | NPN transistor SOT-23 | 1 |
| Q5 | FSS2301M A1SHB | SOT-23-3 P-Channel SOT-23 MOSFET | 1 |
| U1 | 100kHz | 100kHz SOP-8 Timer | 1 |
| U2 | CD4017 | SOP-16 Counter | 1 |
| U3 | AMS1117-3.3 | 1A Fixed 3.3V Positive SOT-223 Voltage Regulator Linear, Low Drop Out (LDO) |
1 |
| U4 | LM358 | SOP-8 Operational Amplifier | 1 |
| Miscellaneous | |||
| H1,H2,H3,H4 | M3 screw column | TH_BD4.7-D3.0 | 4 |
| L1,L2 | XR0410-102 | Color Ring Inductor | 2 |
| L3 | 10uH | SMD,5.2×5.4mm Power Inductor | 1 |
| L4,L5,L6,L7,L8 | 10uH | L0805 SMD inductor | 5 |
| SW1 | HX SS12D07VG4 | Slide Switch | 1 |
| SW2 | DSWB08LHGET | 8-bit SPST DIP Switch | 1 |
| SW3,SW4 | TS-1002S-06026C | 6x6mm Tactile Switch | 2 |
| USB1 | KH-TYPE-C-2P | 2P Type-C USB Connector | 1 |
| X1 | 32.768kHz | 32.768kHz SMD crystal oscillator SMD3215-2P | 1 |
| X2 | 12MHz | 12MHz SMD crystal oscillator SMD3225-4P Crystal | 1 |
Download files, links, and notes
- Download PCB in Gerber + BOM + Centroid file + PDF + PNG + SVG
- Mirror
- BUY Welding practice board
- PDF Datasheet NE555
- PDF Datasheet Cd4017
Source: https://oshwhub.com/course-examples/jia-li-chuang-eda-zong-he-han-jie-lian-xi-ban
