专利快速检索-快速检索全球专利，免费商用专利数据库-IPRDB

1. 发明专利

DE1817259A1 未知
公开(公告)号：DE1817259A1
公开(公告)日：1969-07-24
申请号：DE1817259
申请日：1968-12-27
申请人： GEN ELECTRIC
发明人： LEE WALKER RICHARD
IPC分类号： G11B27/26 , H01J39/12
摘要： 1,252,599. Transistor switching circuit. GENERAL ELECTRIC CO. 17 Dec., 1968 [26 Dec., 1967], No. 59937/68. Heading H3T. [Also in Division G5] In a record/playback apparatus (see Division G5) the presence of a metal marker on a record is sensed by a light source and two photo-cells 28, 29 connected in a circuit to provide output signals of respective terminals 56, 60. With no marker present, equal currents I 5 , I 6 in the cells are set by potentiometer 44 and transistors 36. 37 conduct to provide zero output on terminals 56, 60. With a marker sensed by cell 28 say, transistor 37 is biased off to provide a + 3V signal at terminal 56. In a modification (Fig. 7, not shown) quiescent current through photocells (28, 29) causes transistors (82, 83) and (88 92) to conduct and provide a low positive voltage on terminals (91, 95) which are each connected to the base of one and the emitter of another transistor (89, 93) to bias these off and allow transistors (90, 94) to conduct and provide zero output on terminals (60, 56). When a marker is sensed by cell (28), the voltage at terminal (91) increases while that at terminal (95) remains unaltered thereby causing transistor (89) to conduct, bias transistor (90) off and switch + 3À6V to output terminal 60.

IPRDB

热门服务

关于我们

友情链接

联系方式