This is a tactile momentary switch with single-pole single-throw (SPST) contacts. The contacts are normally open until depressed. The wiring is very simple to deduce using a continuity meter. The height is 4.3 mm, which is just less than 5 mm, and the footprint is 6 mm × 6 mm. These switches are utilised in keyboards for general switch input and are PCB mounted.
|Product Name||Tactile Momentary Switch|
|Dimensions||6 mm × 6 mm × 4.3 mm|
|Button Size||1.3 mm × 3 mm|
|Pin Spacing||9 mm × 4 mm|
|Pin Size||2 mm × 1 mm|
|Colour||Black, Silver Tone|
|Net Weight||13 g|
Inside there are metal strips connecting one end of the terminals to the other end. Even though it is a 4-pin switch you only ever need to connect two terminals, but the extra pins are useful for PCB mounting.
For the replica Sinclair ZX80 project, I decided to use these switches, as the rubber membrane is difficult to find. However, there are firms providing custom membrane keypads, which are extremely cost-effective and can save you from soldering hundreds of these SMD switches.
It fits nicely on my replica ZX80 kit PCB.
This switch is in the SMD style and as a result the terminals are short and exactly the length required for PCB mounting
These switches are available from a wide range of places such as eBay, Amazon, and RS. I managed to buy 50 for £2.50 on eBay and it came all the way from China.