GB2236216A

GB2236216A - Transformer and connector assembly

Info

Publication number: GB2236216A
Application number: GB8920573A
Authority: GB
Inventors: Robert Ernest Myson
Original assignee: Luminaire Developments Ltd
Current assignee: Luminaire Developments Ltd
Priority date: 1989-09-12
Filing date: 1989-09-12
Publication date: 1991-03-27
Anticipated expiration: 2009-09-12
Also published as: WO1991004565A1; AU6410490A; GB2236216B; GB8920573D0

Abstract

A transformer and connector assembly comprises a housing (1) in which a transformer, transforming a mains supply to low voltage (e.g. 12V) for lighting equipment, is encapsulated in a rigid resin. A water-tight connector box (2) is mounted on the housing, and the primary and secondary windings connector wires (4) pass through the encapsulating resin and into the connector box (2). The resin seals the wires (4) and provides an integral assembly.

Description

TRABSFORMER AND COKEECTOR ASSEELBLY This invention relates to a transformer and connector assembly, particularly but not exclusively for use in an outside environment.

Transformers are often used for low voltage (compared to standard mains supply) lighting systems, particularly for display and decorative purposes. The transformers and associated connector assemblies which are generally available lack integration and compactness, especially when used in adverse environmental conditions, where they need to be placed in enclosures which normally have to be ventilated or be of relatively high volumetric capacity to avoid overheating.

It is an object of the present invention to provide a transformer and connector assembly which ameliorates the aforementioned problems.

According to the present invention there is provided a transformer and connector assembly comprising a transformer having connecting wires for the primary and secondary of the transformer, with a water-tight connector box mounted on the transformer, such that the wires extend through apertures into the connector box and in which the transformer is encapsulated within its housing with a rigid resin which seals the apertures between the transformer and connector box to provide an integral assembly.

Preferably the primary and secondary wire connectors are separated by a partition within the connector block. Preferably cable glands made from a laminated rubber compression bush, provide a compressable seal between external cables and the connector box. The bush is adjustable for different sized cables by removal of one or more of the laminated bushes.

A bracket is provided on the transformer for mounting the assembly to a wall or any other convenient fixing. Preferably an adjustable band is attached to the bracket for fixing the assembly to a post or other similar vertical structure.

Preferably the assembly is mounted such that the external cables enter the connector box at the lower side of the box.

Preferably the transformer is of a toroidal winding type, for mains to 12 or 24 volt conversion.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 is a front view of an assembly; Figure 2 is another front view of the assembly of Figure 1 with a connector block insert; Figure 3 is a side view of the assembly of Figure 1; and Figure 4 is a view from beneath the assembly of Figure 1.

Referring to the Figures 1 to 4 there is shown a circular-shaped housing 1 containing a mains to 12 volt transformer which is attached to a connector or terminal box 2 by screws 3. In Figure 1 the transformer housing 1 is furthermore attached to the terminal box 2 by screwed nipples 4, allowing wires 6 for the primary and secondary of the transformer 1 to extend into the terminal box 2. The primary terminal has multiple terminals to allow different voltage selections as required, depending on the load conditions and input voltage. A screened breather hole 5 is provided in the terminal box 2 to allow air circulation to prevent condensation build up within the box 2, and pressure build up within the box 2 due to temperature changes within the box 2.

In Figure 2 a connector block 7 is shown in place, with the wires 6 screwed in place to the relevant terminals 8. Double protection is provided with a self resetting thermal fuse incorporated in the windings of the transformer 1 and a replaceable anti-surge fused 9 is provided within the primary connector block 7. A partition 11 is also provided on the connector block 7 to separate the primary 8a and secondary 8b terminals for safety.

in Figure 3 a gap Cexagerated in the Figures) is shown between the transformer housing 1 and terminal box 2, to provide a degree of thermal isolation between them both, due to the heat generated by the windings. A neoprene seal 12 is used between the transformer housing 1 and the terminal box 2. A top hat shaped bracket 13 is attached to the back of the transformer 1 on a screwed shaft 14, which extends through the transformer 1, by a self-locking nut. A worm drive stainless steel band (not shown) is used to clamp the assembly on a vertical pole.

In Figure 4 apertures 16 and 17 are provided for the mains cable and cable to the load respectively. Variable sized resilient seals, made up of a series of bushes are provided to make watertight seals with the cables.

The transformer housing 1 is filled with a self extinguishing grade rigid urethane resin with high electrical and mechanical properties with good resistance to thermal and mechanical shock.

The resin encapsulates the winding but also fills the nipples 4 to provide a water tight and integral seal for the cables 6.

The invention provides a transformer and integral connector assembly which is easily manufactured and yet out performs existing assemblies, due to its water-tightness and compactness, without the need for large and expensive enclosures. The assembly is ideal for use in adverse environmental conditions such as on a seashore or within a greenhouse. The assembly is also ideal for dusty environments such as in industrial or agricultural buildings.

Claims

1. A transformer and connector assembly, comprising a transformer having connector wires for the primary and secondary windings thereof, the transformer being encapsulated in a rigid resin within a housing, and a water-tight connector box mounted on said housing, the connector wires extending through apertures in the housing into the connector box, the resin serving to seal the apertures between the transformer housing and the connector box to provide an integral assembly.

2. A transformer and connector assembly according to Claim 1, wherein the primary and secondary connector wires are separated by a partition within the connector box.

3. A transformer and connector assembly according to Claim 1 or 2, wherein the connector box is provided with cable glands providing a compressible seal between external cables and the connector box, the glands comprising a laminated rubber compression bush.

4. A transformer and connector assembly according to any of Claims 1,2 or 3, wherein a bracket is attached to the transformer housing for mounting the assembly.

5. A transformer and connector assembly according to Claim 4, wherein the bracket carries an adjustable band for attachment around a post or the like.

6. A transformer and connector assembly according to any preceding claim, wherein the transformer is of a toroidal winding type.

7. A transformer and connector assembly, substantially as described with reference to or as shown in the drawings.