Light dimmer switch having remote load current switching

• US 4,334,171 A
• Filed: 07/07/1980
• Issued: 06/08/1982
• Est. Priority Date: 09/14/1978
• Status: Expired due to Term

• Current Assignee: Power Controls Corporation
• Original Assignee: Power Controls Corporation
• Inventors: Cummins, James P., Shaw, Fred M., Parman, Dan F., Wiebush, LeMoey M.
• Primary Examiner(s): Dixon, Harold A.
• Application Number:
  US06/166,057
• Time in Patent Office: 701 Days
• Field of Search: 315/291, 315/DIG. 4, 315/199, 315/194, 307/303, 307/310, 361/386, 361/388, 323/905
• US Class Current: 315/199
• CPC Class Codes: H02M 5/257 using semiconductor devices only
• CPC Class Codes: H05B 39/083 by the variation-rate of light intensity
• CPC Class Codes: Y10S 315/04 Dimming circuit for fluorescent lamps
• CPC Class Codes: Y10S 323/905 Lamp dimmer structure

Abstract

A light dimmer switch is shown that appears as an ordinary snap switch, but will handle high wattage loads. A controller unit is mounted in a switch box and a remote unit which includes a load switching triac is remotely mounted on a heat sink. Current flowing through the triac to the load is varied by the controller unit. Filtering networks and/or shielding reduce radiated noise along lead lines between the remote unit and the controller unit, plus the filtering prevents noise from being conducted internally along the lead lines. Heat conducted along the lead lines from the remote unit is reduced to more than acceptable levels by connecting the lead lines through a terminal to a thin electrically insulating, thermally conductive strip. In turn, the insulating strip is fixed to the heat sink to transmit heat received from the lead lines to the heat sink.

Claims

1. A switch for varying current received by a load from a source of AC power, said switch including a control unit and a remote unit;

said control unit in a first housing comprising means for connecting said load and said source of AC power to a control circuit contained in a control housing of said control unit, said control circuit including first switching means for providing a gate signal during each half cycle of said source of AC power, a vertically actuated lever pivotally mounted in said control housing operating full ON and full OFF contacts at opposite end of pivotal movement thereof, said lever simultaneously with movement to position intermediate positions between said full ON and full OFF changing variable resistance means in said control circuit connected in series with said source of AC power and said load and to said first switch means to vary a trigger point of said first switching means, wiper means of said variable resistance means being position by said vertically actuated lever mounted in said control housing;

said remote unit in a second housing comprising second switching means mounted on a heat sink inside a second housing, said second housing being remotely located from said first housing, said remote unit having at least three leads connecting to said control circuit of said control unit, a first of said leads connecting said gate signal to a gate terminal of said second switching means, a second of said leads connecting said source of AC power to a first side of said second switching means, and a third of said leads connecting said load to a second side of said second switching means, said second switching means receiving said gate signal during each half cycle of said source of AC power to allow conduction of load current therethrough when not disconnected or bypassed by said contacts, heat from said second switching means being dissipated in said heat sink;

electrical connecting means for said leads comprising a thin, electrically insulating thermally conductive strip having one side secured to said heat sink and terminals positioned on a second side of said strip, said strip and said terminals being attached to said heat sink by screws, said screws being electrically insulated from said heat sink and connecting to said first, second and third leads;

said switch having a maximum rating of between 600 watts to 3000 watts for delivering to said load, first filter means in said second and third leads between said control unit and said remote unit wherein said remote unit switches current being delivered up to said maximum rating, said first filter means preventing RFI noise from interfering with normal AM broadcast bands;

said control unit including said first housing and electrical connections thereto being adapted to fit inside a standard switch box without extra heat sinks attached thereto.

2. The switch as recited in claim 1 comprising second filter means in said control unit connected between said first switching means and said source of AC power, said first filter means being located in said remote unit.

3. The switch as recited in claim 2 comprising shielding means along said leads to prevent RFI noise radiation, said control housing and said second housing being mounted in electrically conductive switch boxes.

4. The switch as recited in claim 1 wherein said first filter means is constructed from an LC circuit having a capacitor and inductor, said capacit having a range of 0.1 to 0.3 microfarads and said inductor having a range of 1 to 200 microhenries.