Insulation-displacement connector

From Wikipedia, the free encyclopedia

An insulation displacement connector or Insulation piercing connector is a connector that pierces the insulation on a wire to make the connection, removing the need to strip the wire before connecting. Such connections are usually seen in low current applications such as telecoms, networking and signal connections between parts of an electronic or computer system. When properly made, the connector blade cold-welds to the wire, making a gas-tight connection.^[1]^[2]

The 'V' mark (ringed) shows the position of pin 1

1 Ribbon cable
2 Telephone and network plugs
3 Punchdown blocks
4 Common layouts
- 4.1 Computing
5 References

[edit] Ribbon cable

Ribbon cable (a.k.a. multi-wire planar cable) is designed to be used with multi-way IDC connectors in such a way that many IDC connections can be made at once, saving time in applications where many connections are needed. These connectors are not designed to be reusable, but can often be re-used if care is taken when removing the cable.

Pin 1 is typically indicated on the body of the connector by a red or raised 'V' mark

Connectors are categorized by pin spacing in mm (pitch), number of pins, and number of rows. Common connectors are:

IDE 3.5" - 2.54mm pitch, 40 pins, 2x20 (2 rows of 20 pins)

IDE 2.5" - 2.00mm pitch, 40 pins, 2x20 (2 rows of 20 pins)

Serial DB9 on Motherboards - 2.54mm pitch, 10 pins, 2x5 (2 rows of 5 pins) - AKA "everex"

[edit] Telephone and network plugs

In some types of telephone and network plug including the BS 6312 and the registered jack family, generally separate wires in a sheath are used. In these applications, the outer sheath is stripped then the wires are inserted into the connector and a special crimp tool is used to force the contacts into the wires. Traditionally these connectors have been used with flat cable which makes it easy to ensure the right wires go into the right slots. However RJ45 connectors are generally used with Category 5 twisted pair cable which requires carefully arranging the wires by hand before inserting them into the connector.

[edit] Punchdown blocks

Main article: Punch block

Punchdown blocks are intended to take individual wires punched down into each position in the block with a special tool. The exact size of the tool varies by brand which can cause problems for those working on existing installations. It is usually possible to insert wiring without the proper tools though this requires care to avoid damaging the connectors (e.g. just pushing a screwdriver down the middle of the block is a bad idea as it forces the two blades of the connector apart leading to bad contacts). They are generally seen in telephone and network wall sockets, in patch panels and distribution frames, and in telephone equipment like PBXs. It is usually possible to put multiple wires in one way of a punchdown block though if they are of different thicknessess this can cause contact problems for the thinner wire.