GB2215529A - Automatic testing apparatus - Google Patents

Abstract

Automatic testing apparatus comprises a mounting member (1) in the form of a rotatable disc, providing a plurality of mounting positions (2) each formed by a plurality of electrical terminals (3) to which a component to be tested can be connected. A plurality of testing stations (A to E) are spaced around the disc (1), and by rotation of the disc (1) components mounted at the positions (2) are tested at each of the stations (A to E) in turn. A base (5) on which disc (1) is mounted comprises a set of terminals (10) which contact undersurfaces (4) of respective terminals (3) of a selected mounting position (2). <IMAGE>

Description

TESTING APPARATUS This invention relates to testing apparatus, and in particular to automatic testing apparatus for the testing of electrical components.

Apparatus for the testing of, for example, transformers and other wound electrical components requires some form of switching arrangemnet in crder to route the necessary drive and measurement signals to, for example, a specific winding or group of windings of a component under test.

The required tests for a supply transformer might be, for example: a) Insulation test at 2KV or more.

b) Measvrement of the excitation current at full primary drive level.

c) DC winding resistance measurement.

d) Leakage inductance measurement.

e) Turns ratio measurement.

Such tests place incompatible requirements on the switches of any switching arrangement that tight be used. For example test c) requires switches with low thermal e.m.f. across the contacts (for exzzple a semiconductor switch rather than a relay) in ormer to achieve good resolution when measuring very lo DC winding resistances, while test a) requires switches with only a ver high isolation capability. Tests b), d) and e) are AC tests where thermal e.m.f. is unimportant but where good switching performance, low contact resistance and possibly fast settling are important.

In general the above requirements cannot be met with a switchin arrangement in the form of a simple relay fixture to give the best all round performance.

If a single test station is used the tests have to be carried out consecutively on single components, and test a) can take between 3 and 60 seconds to complete, this severely limiting the throughput of the apparatus. Further, with a single test station apparatus a fault could result in lethal voltages appearing at the component connection terminals while an operator was connecttng or disconnecting a component under test, the apparatus thus being unsafe.

In order to overcome these difficulties either the different tests are carried out at different dedicated test stations, this involving much handling of the components under test and rendering the apparatus less automate~, or safety features such as interlocks have to be incorporated, this making the apparatus expensive and still not as safe as is desired.

According to this invention there is provided automatic testing apparatus for the testing of electrical components, comprising a mounting member providing a plurality of mounting positions at each of which a component to be tested can be mounted in electrical connection with terminals at the mounting position; means to move the mounting member with components mounted thereon such that each mounting position is moved to each of a plurality of testing stations in turn at each of which a test can be carried out on a component mounted in the mounting position at that testing station; and connection means at each of the testing stations arranged to automatically establish electrical connections between the terminals of a mounting position of the mounting member entering that testing station and external testing circuitry and to break such connections as the mounting position leaves that testing station.

An automatic testing apparatus for the testing of electrical transformers, according to this invention, will now be desired by way of example with reference to the drawings, in which: Figure 1 is a diagrammatic plan view of a mounting member of the apparatus; Figure 2 is a diagrammatic sectional side view of part of the apparatus; and Figure 3 is a sectional side view of a detail of the apparatus.

Referring to the drawings, the apparatus comprises a mounting member 1 providing five mounting positions 2 at each of which a component to be tested (not shown) can be mounted. The mounting member 1 is in the form of a circular disc and is mounted for rotation about its central axis. Each mounting position 2 is formed by an array of socket terminals 3 (best seen in Figure 3) to each of which a lead (not shown) carrying a crocodile clip at its free end can be connected, or a spring clip connector mounted therein. Leads with crocodile clips enable quick connection to components with solder tag or screw terminals while spring clips enable quick connection to components with flying leads.

As clearly shown in Fire 3, each socket terminal 3 extends through the mounting member 1 and has a contact portion 4 embedded in the underside of the mounting member 1.

The mounting member 1 is mounted for rotation relative to an underlying base 5 on wheels 6, driven by a capstan drive arrangement 7.

The mounting member 1 carries a depending peripheral shroud 8 the free eige of which is close to the base 5 (see Figure 3), the space between the mounting member 1 and the base 5 containing connection means 9 serving to automatically establish electrical connections between the terminals 3 on the mounting member 1 and circuitry at each of a plurality of testing stations A to E peripherally spaced about the mounting member 1.

The arrangement is such that as the mounting -member 1 is rotated about its axis relative to the base 5 each mounting position 2 on the mounting member 1 is moved to each of the testing stations A to E in turn, a particular test being carried out at each testing station on any component mounted in the mounting position 2 at that testing station, or the station being used for the loading andjor unloading of a component onto the mounting member 1.

As shown in Figure 3, the connection means 9 at each testing station A to E comprises a plurality of sliding electrical contacts 10 arranged to enagage the contact portions 4 of the terminals 3 carried by the mooting member 1 at each mounting position 2 as the mounting position 2 reaches that testing station and to break such connections as the mounting position leaves the testing station. The sliding contacts 10 are carried by individual posts 11 mounted on the base 5, the posts being connected by leads 12 to external testing circuitry (not shown).

As sho-Fm in Figure 2, the space between the mounting member 1 and the base 5 defined by the shroud 8 is supplied with filtered air under pressure, as indicated by arrow P, to provide a clean atmosphere for the connection means 9. The leads 12 of each testing station A to E are connected to an individual relay matrix which serves for the supply of testing signals to a component under test at that testing station and for the receipt of resultIng measurement signals from the component.

The whole apparatus is controlled by a computer having a display on which the results of testing are displayed.

As previously mentioned the apparatus being described is for testing transformers, and before testing each is given a bar code label which is read by the computer controling the system when the transformer is first mounted on the mounting member 1.

For operation of the apparatus an operator sits at station A and loads a transformer to be tested into the mounting position 2 at station A b connecting it to the terminals 3 of that position by means of leads, as described above. Previously loaded transformers may be at stations B to r being tested at that time.

At station A a safe low voltage level test is carried out, such as leakage reactance or DC winding resistance, where voltage levels less than lCV can be used.

When the set of tests being carried cat at stations A te E are complete and a new transformer has been loaded at station A the mounting member 1 is rotated by the capstan drive arrangement 7 and the mounting positions 2 moved to the next testing station when the set of tests are repeated, this being continued until each transformer has been tested at each testing station and moved to station E for unloading from the apparatus by the operator.

Tests requiring high voltages, for example a Slash or high potential test at EHT potential or a test requiring high AC drive, are carried out at stations B to D remote from the operator.

The mounting member 1 can be covered by a transparent cover member (not shown) providing access for the loading and unloading of transformers to be tested.

The apparatus described has a high throughput since a plurality of tests are carried out on different transformers simultaneously, while being safe due to the physical separation of the different test apparatus at the spaced testing stations.

Claims (14)

1. Automatic testing apparatus for the testing of electrical components, comprising a mounting member providing a plurality of mounting positions at each of which a component to be tested can be mounted in electrical connection with terminals at the mounting position; means to move the mounting member with components mounted thereon such that each mounting position is moved to each of a plurality of testing stations in turn at each of which a test can be carried out on a component mounted in the mounting position at that testing station; and connection means at each of the testing stations arranged to automatically establish electrical connections between the terminals of a mounting position of the mounting member entering that testing station and external testing circuitry and to break such connections as the mounting position leaves that testing station.

2. Apparatus as claimed in Claim 1, in which the mounting member is circular and is mounted for rotation about its central axis, the testing stations being peripherally spaced about the mounting member.

3. Apparatus as claimed In Claim 2, in which the mounting member rotates on wheels mounted at its periphery and running on an underlying base.

4. Apparatus as claimed In Claim 3, in which the mounting member carries a depending peripheral shroud the free edge of which is close to the underlying base, the space between the routing member and the underlying base containing t-e connection means of each testing station and being, in use, filled with a gas at above the surrounding ambient pressure.

5. Apparatus as claimed in Claim 2, Claim 3 or Claim 4, in which the mounting member is rotated by a capstan drive arrangement.

6. Apparatus as claimed in any preceding claim, in which the terminals at each mounting position are sockets.

7. Apparatus as claimed in Claim 6, in which the socket terminals at each mounting position are connected to a component to be tested by means of leads extending between the socket terminals and terminals of the component.

8. Apparatus as claimed in any preceding claim, in which the connection means at each testing station comprises sliding electrical contacts arranged to engage contact portions of the terminals carried by the mounting member at each mounting position.

9. Apparatus as claimed in Claim 8 as dependent upon Claim 3, in which the sliding electrical contacts are mounted on the underlying base and the contact portions of the terminals at each mounting position are embedded in the surface of the mounting member facing the underlying base.

10. Apparatus as claimed in any preceding claim, in which the connection means at each testing station includes an individual relay matrix to which a component under test is connected when at that testing station, which matrix serves for the supply of testing signals to the component under test and the receipt of resulting measurement signals from the component under test.

11. Apparatus-ås claimed in any preceding claim, including a cover-member covering components under test on the mounting member, the cover member providing access=to the mounting member at stations at which access is essential and/or safe.

12. Apparatus as claimed in any preceding claim, including a corputer serving to control the operation of the apparatus.

13. Apparatus as claimed in Claim 12, incling a display on which the results of testing are displayed.

14. Automatic testing apparatus substantially as hereinbefore described with reference to the drawings.