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公开(公告)号：ZA786257B
公开(公告)日：1980-01-30
申请号：ZA786257
申请日：1978-11-07
Applicant: ETTER M
Inventor： ETTER M
IPC: B01D20060101 , B01D
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公开(公告)号：ZA7806257B
公开(公告)日：1980-01-30
申请号：ZA7806257
申请日：1978-11-07
Applicant: ETTER M
Inventor： ETTER M
IPC: B01D20060101 , B01D
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公开(公告)号：IT981633B
公开(公告)日：1974-10-10
申请号：IT2216573
申请日：1973-03-27
Applicant: ETTER M
Abstract: An inverter with a variable output voltage and frequency, intended to supply an a.c. motor or a similar load, in which the variation of amplitude of the output voltage is provided by a chopper supplying the inverter with pulses of variable width or by switching of the inverter itself, is controlled by an electronic circuit in which the voltage supplied by the chopper or the rectified output voltage of the inverter is integrated to give an image of the instantaneous variation of the flux induced in the motor. The output voltage of the inverter is cancelled or reduced each time that the integrated signal reaches a maximum value corresponding to a desired variation of said flux, and the integrated signal is then set to zero. The chopper or the inverter is periodically reset to the minimal switching frequency of the inverter to obtain the desired output frequency or to a whole number multiple of said minimal frequency, means being provided for automatically modifying said multiple when the frequency of the chopper or of the inverter is too small or too large and for making the maximum value of the integrated signal correspond to a variation of flux equal to that obtained at said minimal frequency divided by the said chosen multiple.
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Patent Agency Ranking
公开(公告)号：ZA727959B
公开(公告)日：1974-03-27
申请号：ZA727959
申请日：1972-11-10
Applicant: ETTER M LTD
Inventor： ETTER M
IPC: F16J20060101 , F16J
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公开(公告)号：ZA717115B
公开(公告)日：1973-01-31
申请号：ZA717115
申请日：1971-10-25
Applicant: ETTER M LTD
Inventor： ETTER M
Abstract: The invention concerns a commutator assembly comprising a commutator support in which a plurality of commutator segments having an outer working surface are mounted. A preformed insulating shield is positioned at least partly over the commutator support and is keyed into the commutator segments below the outer working surface thereof. The preformed insulating shield is of hollow cylindrical shape open at one end, and closed at the other end by a plate having an axial hole therein.
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公开(公告)号：NO122536B
公开(公告)日：1971-07-12
申请号：NO14972263
申请日：1963-08-13
Applicant: ETTER M
Inventor： ETTER M
IPC: H02M1/06 , H02M7/51 , H02M7/515 , H02M7/525 , H02M7/527 , H02P9/42 , H02P23/28 , H02P27/04 , H02P27/06 , H02P27/08
Abstract: 1,056,874. Inverting; control of A.C. motors. M. ETTER. Aug. 12, 1963 [Aug. 13, 1962], No. 31719/63. Headings H2F and H2J. In a polyphase inverter comprising a bridge of controlled rectifiers 5, 6 fed from a D.C. supply a, b, and feeding a motor M, control means are provided so that the current waveform attains a desired shape, preferably a sinusoid. With a rectifier 5 conducting a median point 8 is at the positive supply potential, and with a rectifier 6 conducting it is at earth; also diodes 3 and 4 carry provide for the continuance of current when a rectifier shuts off. It is therefore possible to have any desired mean potential for the point 8. Inductors and diodes 44-47 are provided to take up current surges on switching. The switching off of a rectifier is effected by firing two series rectifiers 5, 6, together so as to charge a resonant circuit 50, 51 or 52. The discharge of this circuit through the rectifiers shuts these off. Firing signals are derived from an oscillator 33 (at, say, 3000 c/s.) through a ring-counter 54 giving pulse signals Bi, Bj, Bk, at a signal frequency of 1000 c/s. These signals (Fig. 2d) pass to control units 55, 56, 47, which route each signal to either rectifier 5 (Fig. 2e) or rectifier 6 (Fig. 2f) in order to control the current so that this tends to follow a desired sinusoidal waveform. This routing is effected as follows:- The actual phase current I r (Fig. 2a) is compared with the current a of a sinusoidal source 61 of 1000 c/s. in saturable cores 58, 59, 60. Whenever these current waveforms cross a short pulse is produced (due to reversal of the magnetization) whose sign depends on whether I r is becoming larger ( + ve) or smaller ( - ve) than a (Fig 2b). These short pulses are applied to the units 55, 56, 57, wherein further pulses are produced which are started by a positive short pulse and terminated by the next negative short pulse (Fig. 2c). If the pulses Bi from the ring counter arrive during the presence of a long pulse it is routed to rectifier 6; if, however it arrives during an interval between pulses it goes to rectifier 5. The routing circuitry comprises a transistor arrangement (Fig. 3, not shown).
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公开(公告)号：GB1441811A
公开(公告)日：1976-07-07
申请号：GB3148673
申请日：1973-07-02
Applicant: ETTER M
Abstract: 1441811 Inverting M ETTER 2 July 1973 [14 July 1972] 31486/73 Heading H2F In an inverter in which each phase unit comprises a series chain of two main thyristors T1, T2, across D.C. input terminals ab and having inverse diodes D1, D2 connected as shown, a stepped wave output is obtained by use of two further thrystors T3, T4 connected as shown, between the series chain and at least one intermediate point 0 of the D.C. supply. A commutating source Ca, Cb in series with at least one commutating switch Ta, Tb and a commutating diode D 1 a, D 1 b is connected between each intermediate point 0 and the D.C. supply terminals ab. Auxiliary diodes La ... L 1 b and auxiliary diodes Da, Db are preferably included in the path to the D.C. supply terminals. The inverter is applicable to supply of power to a motor, e.g. at frequencies below 5 Hz. Initially T1 is turned on giving a positive voltage at R until T3 and transistors Ta are turned on so as to turn off T1 by reverse discharge of Ca. The output R is now connected to the intermediate tapping 0. T2 and transistors Tb are now turned on so as to turn off T3 and set the voltage at R to that of line b. The steps are smoothed by inductors LR ... L T . The effective output voltage may be adjusted by pulse width modulation. Diodes D1, D2 may be replaced by thyristors.
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