Patent US1804688A successfully refreshed from Google Patents.
Patent US3896376A successfully refreshed from Google Patents.
US3896376A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for testing insulation by partial discharge technique
Assignee: Micafil AG
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Filing: 1972-12-12
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Granted: 1975-07-22
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Expires: 1992-12-12
Abstract
Abstract Apparatus for testing the insulation of a commutator type armature winding and checking the resistance of the winding at points between pairs of commutator segments comprises an inductor-stator provided with a multiphase winding and within which the armature is mounted in a non-rotative manner for testing. A pulse-like rotating magnetic field produced in the stator winding by means of an oscillating circuit induces high test voltages in the winding which are taken out through contact pins connected to the commutator segments to an active filter unit which separates the high-frequency partial-discharge voltages from the test voltage, the filter unit being followed by a discriminator which determines whether the insulation on the armature winding is satisfactory or not. The ohmic resistance of the armature winding is measured by application of a test current which is sent through different parts of the winding in succession established by connection of a d.c. test voltage to successive pairs of the commutator segments, the magnitude of the test current in each instance being indicative of the resistance value of the part of the winding being tested.
Inventors
- 👤 Edgar Sinniger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:45
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/34
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
239 words
Apparatus for testing the insulation of a commutator type armature winding and for also separately checking the resistance of the winding which comprises, for insulation testing, an inductor-stator provided with a multi-coil winding and within which the armature is mounted in a non-rotative manner, means producing from test voltage pulses a rotary magnetic field within said inductor-stator including means for sequentially energizing said coils with corresponding test voltage pulses each of which has the configuration of a damped sinusoidal oscillation and which serve to induce corresponding voltage pulses in different portions of the armature winding, contact means engaged with the commutator segments and which connect the different portions of the armature winding with an active filter unit which serves to separate the high-frequency partial discharge components from the fundamental of the damped sinusoidal oscillation, and a discriminator connected to the output of said filter unit for determining whether or not the insulation on the armature winding is satisfactory; and which comprises for resistance testing, a test voltage source connected to successive pairs of the commutator segments through said contact means for effecting corresponding flows of test current through the corresponding parts of the armature winding, means for measuring the magnitude of the test currents which are indicative of the resistance of the winding parts, and a second discriminator connected to the output of said measuring means for determining whether or not the armature winding parts have satisfactory resistance values.
Claim 2
Dependent Claim
239 words
Apparatus for testing the insulation of a commutator type armature winding and for also separately checking the resistance of the winding which comprises, for insulation testing, an inductor-stator provided with a multi-coil winding and within which the armature is mounted in a non-rotative manner, means producing from test voltage pulses a rotary magnetic field within said inductor-stator including means for sequentially energizing said coils with corresponding test voltage pulses each of which has the configuration of a damped sinusoidal oscillation and which serve to induce corresponding voltage pulses in different portions of the armature winding, contact means engaged with the commutator segments and which connect the different portions of the armature winding with an active filter unit which serves to separate the high-frequency partial discharge components from the fundamental of the damped sinusoidal oscillation, and a discriminator connected to the output of said filter unit for determining whether or not the insulation on the armature winding is satisfactory; and which comprises for resistance testing, a test voltage source connected to successive pairs of the commutator segments through said contact means for effecting corresponding flows of test current through the corresponding parts of the armature winding, means for measuring the magnitude of the test currents which are indicative of the resistance of the winding parts, and a second discriminator connected to the output of said measuring means for determining whether or not the armature winding parts have satisfactory resistance values.
Claim 3
Dependent Claim
64 words
Test apparatus for wound commutator type armatures as defined in claim 1 wherein a capacitive multiple bridge circuit is included in said connection means from said contact means to said active filter unit, and said active filter unit is constituted by a high pass filter element, a cathode-follower amplifier connected to said high pass filter element and a rectifier connected to said cathode-follower amplifier.
Claim 4
Dependent Claim
49 words
Test apparatus for wound commutator type armatures as defined in claim 1 wherein said means for measuring the magnitudes of said test currents indicative of resistance characteristics of the commutator winding parts comprises a timing pulse generator, an amplifier with logic, a programmed counter, and a shift register control.
Claim 5
Dependent Claim
73 words
Test apparatus for wound commutator type armatures as defined in claim 1 wherein said means for producing said rotary magnetic field within said inductor-stator comprises a polyphase transformer, an oscillator circuit for each coil of said inductor-stator including a condenser connectible therewith, means for periodically charging each said condenser from a corresponding secondary winding of said transformer, and means for periodically connecting the charged condenser to its corresponding inductor-stator coil for discharge therethrough.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-21 | 1979-01-20 | 1979-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-21 | 1983-01-20 | 1983-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-21 | 1987-01-20 | 1987-07-22 | $7700.00 | Window Closed / Lapsed |