| 摘要 |
<p>1415634 Supply systems for induction furnaces AJAX MAGNETHERMIC CORP 10 April 1974 [24 Sept 1973] 16034/74 Heading H2H A single phase induction furnace 10 is provided with capacitors C 1 fixedly connected in parallel therewith and capacitors C 2 which are selectively connected in parallel therewith by means of baok-to-baok thyristors R 1 , and capacitors C 3 which are selectively connected in series therewith by means of back-to-back thyristors R 2 , the capacitors C 1 , C 2 serving to set the phase angle between the voltage V 1 across the furnace 10 and the voltage V 2 across the capacitors C 3 and thyristors R 2 thereby setting the permissible range of power within which the furnace may operate as the impedance of the furnace varies during a work cycle and the capacitors C 3 setting the furnace voltage and hence the power at which the furnace operates within the range. The necessary firing pulses for the thyristors R 1 , R 2 are developed by means of firing control units 13, 14 respectively and in a further embodiment the phase angle between the voltages V 1 , V 2 is held constant for varying load impedance by further devices which control the units 13, 14. If desired the thyristors may be replaced by triacs.</p> |
