| 摘要 |
1,115,644. Current supply to electric heating films. P. EISLER. 26 May, 1965 [26 May, 1964; 11 Aug., 1964], Nos. 22377/65 and 32665/64. Heading H5H. Electric current connections, for a space heating system of a plurality of rooms by means of large area electric resistance heating films operating on a low voltage derived from the secondary of a mains transformer located outside of one of said rooms, are adapted firstly to permit instant connection and disconnection of any pre-arranged grouping of said heating films to said secondary voltage at will by at least one movable switch contact placed in a live link connecting to at least one group of heating films, and secondly to permit the easy adaptation of said pre-arrangement to different local conditions by provision of readily accessible fixed pressure contacts between thin conductive areas extending from the individual heating films, both the movable and the fixed contacts extending over such a large area with so many points of direct metal-to-metal contact that the heat generated by the large current passing through the contact resistance does not raise the contacts to a temperature above the maximum temperature attained by the heating film. Movable contacts.-In Fig. 1 two groups 15a and 15b of heating film in series are connected to the secondary winding of a transformer 14 through a fuse 17 and a switch 16 having a movable contact 16a and fixed contacts 16b and 16c of large area. Solenoid 135 is supplied by an auxiliary transformer 18 and is connected through a lamp 19 to fixed contact 16c. Movable contact 16a engages contact 16c during opening or closing of the switch, thus energizing the solenoid 13S and lamp 19 and disconnecting the mains supply from transformer 14. The solenoid 13S may be operated by D.C. by including a rectifier in the secondary circuit of transformer 18. The switch 16 may be operated by a solenoid (23) (Figs. 2 and 3, not shown), remotely controlled by a push-button switch (24), (Fig. 2), or by a thermostat (27) (Fig. 3). A more sophisticated switching circuit (Fig. 4, not shown) enables groups of heating films (HP1, HP2) to be connected initially in parallel and later in series by a four-position switch (SW) operated by a solenoid (S) under the control of thermostats (BM1, BM2) with overriding control by remote manual switches (PB1, PB2). Fixed contacts.-Each portion of heating film has a bus-bar extending along each side edge, and contact is effected in Fig. 5 by laying connecting strips 61, 62 on the floor boards and securing the bus-bar terminals 63, 64 thereto by nails or staples 65 over a length of at least two strip widths. Resilient staples may be used or spring washers placed under the nail heads or staples to ensure elastic pressure contact. In alternative arrangements (Figs. 6-9, not shown) the connecting strips are mounted behind a skirting board or behind a vertical angle member in a comer of the room. |
