GB2154805A

GB2154805A - Dimmer switch with removable component sub- assembly

Info

Publication number: GB2154805A
Application number: GB08504278A
Authority: GB
Inventors: David Maurice Graff
Original assignee: LOGITRONICS Pty Ltd
Current assignee: LOGITRONICS Pty Ltd
Priority date: 1984-02-27
Filing date: 1985-02-19
Publication date: 1985-09-11
Also published as: GB8504278D0

Abstract

A dimmer switch has a sub- assembly containing a Triac (10), several capacitors, several resistors and a damping coil (26). The sub- assembly can be readily removed wholly or partially from a protective housing (40) for maintenance and repair without disconnection or partial dismantling of the components. When the sub- assembly is inserted into the housing (40) the Triac slides into contact with a metallic U-shaped part (38) forming a heat sink attached to a wall mounting frame (36). <IMAGE>

Description

SPECIFICATION Dimmer switch with removable component sub-assembly BACKGROUND OF THE INVENTION The invention relates to light dimmers.

Light dimmers are often provided for use with domestic lights enabling the brightness of the light to be controlled as required. The dimmers are conveniently mounted next to or incorporate a light switch. Light dimmers usually include a Triac which is adjustably controllable and via which the power is supplied to the light.

The Triac and associated components of the dimmer are conventionally mounted in a protective casing which is supported on a metallic wall mounting frame.

SUMMARY OF THE INVENTION According to the invention there is provided a dimmer switch including a Triac and electrical components in a protective housing mounted on a frame, in which the Triac and at least some of the components are provided as a sub-assembly arranged to be readily withdrawn at least partially from the housing to give easy access to the Triac and the components.

The frame is usually formed of metal and provides a heat-sink for the Triac in which case the Triac is preferably arranged to slide into and out of physical contact with the metal frame when the sub-assembly is respectively fitted into and withdrawn from the casing.

BRIEF DESCRIPTION OF THE DRAWINGS A dimmer switch according to the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 is an isometric exploded view of the switch; and Figure 2 is a sectional view of part of the switch.

DESCRIPTION OF PREFERRED EMBODI MENT Referring to the drawing, the dimmer switch includes various electrical components which form a sub-assembly comprising a Triac 10; capacitors 12, 14, 16 and 18; resistors 20,22 and 24; and a damping coil 26. A variable resistor 28 is also included which is adjusted by a dimmer control knob 30 (see Fig. 2) and connected to the other components by electrical leads 32.

An ON/OFF switch 34 is mounted on a wall mounting frame 36. The frame 36 is provided with a metallic U-shaped part 38 fixed thereto which has limbs which extend upwards and into a plastic protective housing 40. A lid 42 is provided for the top of the housing 40.

The Triac 10 and electrical components 12 and 26 formed as the sub-assembly mounted on a printed circuit board fit into the top of the housing 40. This means that for maintenance, servicing or replacement of the Triac 10 or the components 12 to 26 the subassembly can be totally or partially removed from the housing 40. In this manner easy and ready access to the Triac and the components is achieved after assembly and use of the dimmer switch without difficulty and without random or partial dismantling of components as is presently required in available dimmer switches.

The U-shaped part 38 forms part of a heatsink for the Triac 10 and the Triac 10 slides into and out of physical contact with one of the limbs of the part 38 as the sub-assembly is placed into or removed from the housing 40. It is customary in other dimmer switches to securely mount the Triac onto a heat-sink using a screw or bolt. In the described embodiment, the sliding contracting arrangement not only provides sufficiently good heat transferring properties but also enables ready removal of the sub-assembly from the housing 40.

The housing 40 is normally a sliding fit on the U-shaped part 38 which also facilitates assembly and dismantling of the overall dimmer switch components.

Claims

1. A dimmer switch including a Triac and electrical components in a protective housing mounted on a frame, in which the Triac and at least some of the components are provided as a sub-assembly arranged to be readily withdrawn at least partially from the housing to give easy access to the Triac and the components.

2. A dimmer switch according to Claim 1, in which the frame is formed of metal and forms a heat-sink for the Triac and the Triac is arranged to slide into and out of physical contact with the frame when the sub-assembly is respectively fitted into and withdrawn from the housing.

3. A dimmer switch according to Claim 2 in which the frame is U-shaped and the housing is supported by and slides onto the limbs of the frame.

4. A dimmer switch according to Claim 3 including a lid for the protective housing which fits over the top of the housing and covers the sub-assembly when in the housing.

5. A dimmer switch substantially as herein described with reference to Figs. 1 and 2 of the accompanying drawing.