CN2390353Y

CN2390353Y - Power supply for electric screwdriver

Info

Publication number: CN2390353Y
Application number: CN 99239106
Authority: CN
Inventors: 任国良
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-07-25
Filing date: 1999-07-25
Publication date: 2000-08-02
Anticipated expiration: 2009-07-25

Abstract

The utility model relates to a power supply for an electric screw driver, which comprises a transformer B with four tap secondary coils and a rectifying filter circuit RF; the output of the rectifying filter circuit RF is the output of the power supply. The utility model is characterized in that the utility model also comprises two single-pole double throwing type switches K1 and K2; the fixed ends of the switches K1 and K2 are respectively connected with two input ends of the rectifying filter circuit RF, wherein, the movable end of K1 is respectively switched to the tap I and the tab II. The movable end of K2 is respectively switched to the tab III and the tab IV. The utility model, through the arranging combination of the two respectively switching states of the two single-pore double throwing type switches, has four adjustable voltages; the utility model is more durable and is hard to damage corresponding to a shifting switch.

Description

A kind of power supply that is used for electric screwdriver

The utility model relates to a kind of power supply that is used for electric screwdriver.

Electric screwdriver will carry out speed change in use as required, and speed change is to realize by the output voltage that changes DC power supply, the general employing one of existing electric screwdriver power supply has the transformer B of four tap secondary coils, one of them tap is the benchmark utmost point, K switches one of other three taps as the work utmost point by triband machinery toggle switch, behind follow-up current rectifying and wave filtering circuit RF, export again as DC power supply, referring to Fig. 4, its shortcoming is that toggle switch relatively easily damages, and has only three kinds of voltages adjustable all the time.

The purpose of this utility model provides a kind of four kinds of electric screwdriver power supplys that voltage is adjustable that have with regard to being at above-mentioned prior art present situation.

The purpose of this utility model is achieved in that the power supply of electric screwdriver comprises that one has transformer B, the current rectifying and wave filtering circuit RF of four tap secondary coils, the output of current rectifying and wave filtering circuit RF is power supply output, it is characterized in that also comprising two single-pole double throw type K switch 1, K2, the stiff end of K switch 1, K2 connects two inputs of current rectifying and wave filtering circuit RF respectively, wherein the movable end of K1 switches tap I and tap II respectively, and the movable end of K2 switches tap III and tap IV respectively.

Compared with prior art, the utility model can have four kinds of voltages adjustable through two single-pole double throw type switches permutation and combination of two switching states separately altogether, and toggle switch is more durable, not fragile relatively.

Description of drawings:

Fig. 1 is circuit theory diagrams of the present utility model.

Fig. 2 is the front view of the utility model embodiment.

Fig. 3 is the right view of Fig. 2.

Fig. 4 is the circuit theory diagrams of existing electric screwdriver power supply.

Embodiment is described in further detail the utility model below in conjunction with accompanying drawing.

As Fig. 1～shown in Figure 3, the power supply of electric screwdriver comprises that one has transformer B, the current rectifying and wave filtering circuit RF of four tap secondary coils, the output of current rectifying and wave filtering circuit RF is power supply output, it is characterized in that also comprising two single-pole double throw type K switch 1, K2, the stiff end of K switch 1, K2 connects two inputs of current rectifying and wave filtering circuit RF respectively, wherein the movable end of K1 switches tap I and tap II respectively, and the movable end of K2 switches tap III and tap IV respectively.

Obviously, difference according to the movable end switching state of K switch 1, K2, common property is given birth to the combination of following four kinds of states: I-III, I-IV, II-III, II-IV, therefore current rectifying and wave filtering circuit RF will have four kinds of different input voltages, thereby also just have four kinds of different output voltages, the usefulness of the moving screwdriver control of power supply makes it to have four kinds of different rotating speeds.

Claims

1. power supply that is used for electric screwdriver, comprise that one has transformer B, the current rectifying and wave filtering circuit RF of four tap secondary coils, the output of current rectifying and wave filtering circuit RF is power supply output, it is characterized in that also comprising two single-pole double throw type K switch 1, K2, the stiff end of K switch 1, K2 connects two inputs of current rectifying and wave filtering circuit RF respectively, wherein the moved end of drawing together of K1 is switched tap I and tap II respectively, and the movable end of K2 switches tap III and tap IV respectively.