| 摘要 |
956,153. Battery charging systems; electrically released switches. ACCUMULATORENFABRIK SONNENSCHEIN G.m.b.H. Dec. 22, 1960, No. 44136/60. Headings H2B and H2H. A rectifying semi-conductor element 2 such as a Zener diode having a non-linear voltage/ resistance characteristic has a heat-sensitive material 3 mounted in heat-exchange relationship with the element 2 which heats up at a predetermined voltage and causes the element 2 to initiate a switching and/or signalling step. A small permanent magnet 4 previously attracted to the material 3 through polepieces 5 against the pull of a spring 7, is released when the element 2 heats up and causes the material 3 to reach its Curie point so that the spring 7 pushes a knob 6 out of the casing 8 and parts a pair of switch contacts 10 by means of a non-conducting blade which may be also so shaped that a second pair of contacts can be additionally interrupted after a short time delay. The movement of the knob 6 serves as an indication that the switch has operated and it can be reset by depressing the knob 6 after the material 3 has again become magnetic. The switch may alternatively be actuated by a bi-metallic strip or by a heatdependent expandable fluid. In a battery-charging and loading circuit shown in Fig. 3, the heat evolved by a Zener diode 16 when a battery 12 is fully charged, opens contacts 14, 14a and limits the charging current from the source U by a resistor 23. When the battery is loaded, switch 15 is put into position B so that diode 16 may constitute an active component in the load circuit. A semi-conductor 27 such as a tunnel diode, is arranged to draw little current when the battery is charged, but when this has been discharged and its voltage drops, the diode 27 draws a current ensuring sufficient heat to open the contacts 29. A thermally-controlled switch 19 prevents the diode 16 energizing heat and hence interrupting the switch 14, when the battery 12 is in the discharged state. |
