GB1290655A - - Google Patents

Abstract

1290655 Thermoelectric devices BAUMGARTNER FRERES SA 20 Jan 1970 [31 Jan 1969 7 May 1969] 2679/70 Heading H1K In a thermoelectric generator comprising a radioactive heat source and thermoelectric units, the thermoelements are in the form of thin film layers applied to a carrier strip of electrically insulating and thermally conductive material compacted in a coil or meander form. In a first embodiment, Fig. 11 (not shown), a radioactive heat source (1) of Pu238 enclosed in a sealed casing (2) of Ta or Pt is surrounded by thermoelectric units (4) and enclosed in an outer casing (6). Thermally conductive electrically insulating layers (3, 5) may be provided on either side of the units but these layers may be omitted if the thermoelements stop short of the edges of the carrier on which they are formed. The carrier may be wound to form a spiral, Fig. 3 (not shown), or folded in meander form with interposed insulation where required, Fig. 4 (not shown). In a second embodiment, Fig. 2 (not shown), a short cylindrical nuclear heat source (1, 2) is placed between two thermoelectric units (4) and surrounded by a cylinder (7) of insulating material which is enclosed in a metal case (6, 6<SP>1</SP>) which is itself enclosed in a sealed and evacuated glass bulb. An annular evacuated gap between the insulating cylinder and the metal case reduces lateral heat losses. The thermoelements may be of Bi 2 Se 3 , PbTe or SbBi or of suitable metals and may be vapour deposited on the carrier.