| 摘要 |
935,296. Charging and discharging capacitors. ROBOTRON CORPORATION. Aug. 4, 1960 [Sept. 25, 1959; April 18, 1960], No. 27089/60. Class 38 (4). An apparatus for supplying high amplitude pulses of electrical energy to a load L, particularly a resistance welder comprises a capacitor 5, reverse parallel connected phase-controlled thyratrons or e.g. nitrons 4, 6 and an inductance series connected across an A.C. supply 1, 2. During a first half cycle, when thyratron 6 is conducting, capacitor 6 charges until its voltage is equal to a point on the sign wave when thyratron 6 extinguishes. On the next half cycle, when thyratron 4 conducts, the capacitor 5 voltage aids the supply voltage causing a high amplitude pulse to traverse the inductance 9 which forms the primary winding of a transformer feeding the load L, which pulse continues until the capacitor is re-charged to the opposite polarity, when the thyratron 4 extinguishes. By varying the cycle point at which the thyratrons conduct, the pulse amplitude may be varied, thus being a maximum at the middle of each half cycle. By connecting a plurality of series-connected capacitors and pairs of thyratrons having different firing points in parallel, several pulses per half cycle may be formed. Arrangements, also having a plurality of capacitors and thyratrons fed from a 3-phase source are described in the Specification giving pulses of alternating polarity at 60 degrees spacing. |
