| 摘要 |
<p>1,045,292. Control systems for heating resistors; magnetic switches. TECHNE (CAMBRIDGE) Ltd. Jan. 21, 1965 [Feb. 17, 1964] No. 6533/64. Headings H2B and H2H. An electric heating system for laboratory apparatus such as a water bath comprises a main heating element controlled by a thermostat and a boost heating element controlled by an electromagnetic relay, the relay armature operating a micro-switch to energize the boost element when the main element is initially energized to ensure rapid initial heating of the apparatus, the boost element being de-energized when the thermostat first operates to deenergize the main element and thereafter to remain de-energized whilst the temperature of the apparatus is maintained by the main element and the thermostat. The relay may have a manually operated lever associated therewith to bring the armature into proximity with the relay core. If the lever is maintained in such a position the boost element will be cyclically energized with the main element. Alternatively the relay coil may be shunted by a resistor and a switch.</p> |
