Electronic device, PCB and electric tool

An electronic device, wherein comprising:

• a main body, a first electric connecting part, a variable resistor, a speed regulating contact, a reversing electric connecting part, a reversing contact, a speed regulating handle and a reversing handle, wherein the resistance value of the variable resistor varies along the length direction;
• the first electric connecting part is connected with the main body in a melt adhesive curing mode, and one end of the first electric connecting part is exposed out of the main body;
• one of the speed regulating contact and the variable resistor is arranged on the main body and connected with the first electric connecting part, and the other is arranged on the speed regulating handle;
• the speed regulating handle is connected with one end of the main body in a sliding way and forms a first space with the main body;
• the speed regulating contact and the variable resistor are arranged in the first space and are in contact with the variable resistor, and the speed regulating contact is in contact with the variable resistor, under the drive of the reversing handle, the speed regulating contact and the variable resistor relatively slide in the length direction of the variable resistor for speed regulation;
• the reversing electric connecting part is connected with the main body in a melt adhesive curing mode, one end of the reversing electric connecting part is exposed out of the main body, and the reversing contact is arranged on the reversing handle;
• the reversing handle is slidably connected with the other end of the main body, the reversing contact is contacted with the reversing electric connecting part, and under the drive of the reversing handle, the reversing contact and the reversing electric connecting part relatively slide for reversing.