| 摘要 |
<p>1,257,689. Automatic temperature control systems. HITACHI HEATING APPLIANCES CO. Ltd. Dec.9, 1969 [March 7, 1969], No.60131/69. Heading G3R. In an electric blanket of the type having a heating wire 4 surrounded by a signal wire 6 and separated therefrom by a dielectric material whose characteristics change with temperature, the capacity of the dielectric increases and the specific resistance decreases with temperature so that within a temperature rise to a determined value the electric charge in the dielectric retards the firing point of a thyristor 8 progressively, but beyond this point the capacitance changes sharply so that the gate/cathode voltage is insufficient to fire a neon indicator 5 and hence the thyristor 8 is not triggered into conduction. A variable resistor 10 sets the temperature range. The dielectric material is a heat sensitive polyamide composition containing a surface activator, suitable ingredients for which are given in the Specification.</p> |
