This invention relates to a dual-in-line package (DIP) switch, more particularly to a DIP switch having three states.
Referring to FIG. 1, a tri-state DIP switch comprises a base 1 with a plurality of transverse grooves 1a, a plurality of conducting pins 2, a plurality of conducting elements 3, a plurality of slide members 4, and a cover 5. Each of the conducting pins 2 has a conducting strip on the transverse grooves 1a and an extended pointed end folded at the side of the base for connection to an external circuit board. Two of the conducting pins serve as positive and negative input terminals, respectively, for the DIP switch. The plurality of conducting elements 3 are each attached to the bottom surface of one of the plurality of slide members 4. Each slide member 4 rests on one of the grooves 1a and has a length equal to that of the base 1. A plurality of thin shaped partitions 5b are transversely disposed on opposing sides of the plurality of openings 5a at the inner top surface of the cover 5, isolating the slide members 4 from each other. The width of the opening of the shaped partitions is equal to that of the base 1. Each conducting element 3 can be moved to electrically connect one conducting pin 2 to the positive terminal, the negative terminal, or to a space between the positive and negative terminals of the DIP switch. Each slide member 4 has a top protrusion 4a, which protrudes from one of the plurality of openings 5a formed on the cover 5.
A main drawback of this structure is that the cover 5 is joined to the base 1 only by structural means, i.e., the base 1 has a pair of elongated slots formed on its shorter sides and the cover 5 has its shorter sides formed with recessed ends for receiving the elongated slots of the base 1. Thus, the base 1 is not tightly sealed to the cover 5.