Abstract: The invention provides an electronic device, a PCB and an electric tool; the electronic device comprises 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, 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; the speed regulating handle and the main body form a first space, the speed regulating contact and the variable resistor are arranged in the first space, and under the drive of the speed regulating handle, the speed regulating contact and the variable resistor relatively slide; under the driving of the reversing handle, the reversing contact and the reversing electric connecting part relatively slide for reversing.

Abstract: A height self-adjustable walking aid includes two oppositely arranged U-shaped stands which are connected by a front stand. The two ends of each U-shaped stand are sleeved with two outer pipes respectively, and each outer pipe is mounted with a height adjusting apparatus and a control apparatus for height adjusting. The walking aid is adjustable in height according to the heights of users, so as to satisfy the requirement of allowing patients or elders with different heights to use a same equipment, thus providing great convenience for users. The heights of the two ends of each U-shaped stand could be adjustable respectively to generate a height difference between the front end and rear end of the walking end, thus enabling patients or elders to walk up and down the stairs with it.

Abstract: The present invention discloses a height self-adjustable walking aid, comprising two oppositely arranged U-shaped stands which are connected by a front stand, wherein the two ends of each U-shaped stand are sleeved with two outer pipes respectively, and each outer pipe is mounted with a height adjusting apparatus and a control apparatus for height adjusting; the walking aid of the present invention is adjustable in height according to the heights of users, so as to satisfy the requirement of allowing the patients or elders with different heights to use a same equipment, whereby providing great convenience for users; meanwhile, the heights of the two ends of each U-shaped stand could be adjustable respectively, to generate a height difference between the front end and rear end of the walking end, so as to enable the patients or elders to walk up and down the stairs with it.