Patent GB-886660-A (GB)
Title: Improvements in arrangements for automatically performing tests on electrical components
Inventor: CLARK THOMAS HAROLD
IPC: G01R31/01
Filed: 1958-03-06
Abstract: 886,660. Automatic testing-machines; bridge measuring circuits. BRITISH TELECOMMUNICATIONS RESEARCH Ltd. June 8, 1959 [March 6, 1958; July 7, 1958], Nos. 7280/58 and 21708/58. Class 37. [Also in Group XXXVIII] Electrical parameters of components are automatically tested under the control of information presented from a control store in which the information is temporarily transferred to storage devices which then control the setting of a test bridge to which a component is automatically connected and, in accordance with the result of a comparison operation, an indication is given of whether or not the component comes within the allowable tolerance. In the particular embodiment, the control store is punched tape on which the required characteristics of a component are stored, although magnetic drum stores may alternatively be used. The storage devices are electronic toggles, and the bridge is set up in accordance with the required value which is stored on the tape. The components of various values are stored in a number of magazines from which the required component is automatically selected. A detector device causes the components to be either accepted or rejected and provision is made for the immediate selection and testing of a further component in the former case and for disposal and selection of a further component in the latter, provision being made for stopping the machine in the ease of more than a certain number of rejections. Setting up bridge for testing.-The bridge is indicated at B (Fig. 1) and comprises resistance and capacitance testing sections. The three switches range RS, units RU, CU, tenths RT, CT (to give the value) on the bridge are set in accordance with the information set in on the temporary stores TB1-TB5, TB6-TB10, TB11-TB15 respectively controlled through gates GR, GU, GT in accordance with three positions on the punched control tape and with strobes controlled by respective resistance and capacitance bridge selection toggles (Fig. 2, not shown), operated in accordance with punchings on the tape. The required values of resistance or capacitance to which the component is to conform are thus set into the bridge, a tolerance value being set into detector DE through gate GL and stores TB16-TB20 operated in accordance with a punching on the tape corresponding to the tolerance allowed for that particular valve component. An optical detector shows that the component is in position for testing, and a test prod toggle is operated after a delay, and energizes a magnet to cause test prods to engage the component terminals (Fig. 2, not shown). Testing of components.-The detector DE will give an output over lead 21 if the component is accepted and over lead 22 if it is rejected. Considering the latter case first, potential over lead 22 will operate a reject toggle which then energizes a magnet which in turn separates the. sides of a V-shaped support on which the component rests, causing the component to fall down a reject shoot (Fig. 2, not shown). This operates a detector OD3, which causes the resetting of the reject toggle and starts the selection of another component from the magazine. If component is accepted another toggle will be operated to energize a further magnet to remove a stop against which the component rests, and allow it to pass forward to the next operation, for example, to a machine for inserting the component automatically on a board. On the component clearing the testing station, all the toggles are reset due to a blank space in the tape. The component may be tested for length in response to a punching in the tape in an arrangement similar to that for magazine testing, and in which the test is made by seeing how many photo-sensitive devices are obscured by the component. A teleprinter may be used to make a record of the test instead of a record tape, and may also be used to print the results of the tests. The toggles and pulse generators of the arrangement include transistors. One of the Provisional Specifications refers briefly to a complete component circuit board production unit including the testing machine described and component selecting, belting, insertion and transport systems and also a printed circuit board production machine, data handling equipment and a soldering machine. Specification 886,651 is referred to.