| 摘要 |
1275709 Thermoelectric devices K LANDECKER 19 April 1971 [10 March 1970] 22859/71 Heading H1K In a thermoelectric device comprising a P- type limb and an N-type limb joined to form a junction, the limbs are also connected to one another by at least one shunting conductor to provide a leakage current path between the limbs. This leakage path is said to provide the advantages of a cascaded stage thermoelectric unit. As shown, Fig. 1, a pair of doped Bi 2 Te 3 limbs separated by an insulator 11 and joined by a bridge 12 are provided with a shunting conductor 14 comprising a strip of silver which may be applied as a suspension, or by spraying or soldering. The shunt may be divided into a plurality of sections to reduce the longitudinal heat flow. The insulator 11 may comprise a strip of paper secured to the elements with epoxy resin. In a modification a thick suspension of Ag is applied to the adjacent faces of the limbs which are then pressed together to squeeze out excess material, and then secured by binding with insulating tape or by encapsulating in insulator while the suspension dries. In a second embodiment, Figs. 2 and 3 (not shown) a wire is wound round a pair of spaced parallel limbs in a figure of eight pattern, adhered to the limbs and cut at the outer faces of the limbs to divide it into a plurality of separate shunting conductors. In a -third embodiment, Figs. 4 to 6 (not shown) four limbs (two P-type and two N-type) are arranged in a square array and joined by cruciform Ag films subdivided along the length of the limbs. The working junction is provided at one end of the assembly by bridging all four limbs and connections are made at the opposite end so that the limbs form two thermocouples connected in parallel. In another embodiment, Figs. 7 and 8 (not shown) the limbs are in the form of annuli soldered to a metal tube forming a bridge near its ends. Annular contacts are applied to the outer faces of-the limbs and the inner faces of the limbs are coated with Ag films which are connected together by wads of crumpled Al foil to form the shunting conductors. A plurality of such devices may be clamped together so that the tubes form a heat transfer duct. In further embodiments a pair of limbs are joined end to end and Ag patches spaced along their lengths are connected either in symmetrical pairs, Fig. 9 (not shown) or so that all the paths on the N- and P-type limbs are connected to the end contacts of the P- and N-type elements respectively, Fig. 10 (not shown). |
