GB1313793A - Teaching apparatus - Google Patents

Abstract

1313793 Teaching device RANK XEROX Ltd 19 April 1971 [16 April 1970] 18135/70 Heading G5G A teaching device for teaching the logic of fault analysis in electronic, electro-mechanical or pneumatic systems includes a multiplicity of electrical circuit-points whereby circuits may be completed to operate an indicator device providing at least three indications. As shown (Fig. 1), a teaching apparatus includes a housing 1 with a multi-apertured front panel 2 under which is fixed a printed circuit board 15 (Fig. 2, not shown) having a plurality of conductive studs 16 (Fig. 4) each of which is connected in a random non-repetitive manner to one of twelve sources of different potential. Typically there would be over 1000 studs. In operation, a preprinted sheet or card 10 (Fig. 7) is placed on the panel 2 with apertures 11 engaged by locating pegs 9. The student is presented with a circuit diagram of a machine and the symptoms of a fault. The sheet 10 bears identifications of components which might be faulty. Having selected a component to be tested and using a probe 19 the student pierces the sheet 10 in the marked area to contact one of the studs 16 whereby the potential of the stud is connected to a voltmeter 6 the scale of which is arranged to give an indication of the correctness or otherwise of the response. All but one of the potentials of the studs 16 are below the threshold of a Zener diode in series with a lamp 8 so that only when a stud at the potential above this threshold is contacted will the lamp 8 illuminate to indicate a correct response. The voltmeter may have several sets of indications for each voltage level (Fig. 6, not shown), the appropriate indication in any particular case being indicated by symbols on the sheet 10. The voltmeter may be replaced by or supplemented by a cathode ray oscilloscope. The apparatus also includes an electrical timer device, Fig. 8, not shown, which punctures a timing scale 37 on the sheet 10 to indicate the beginning and end of the test. This device is the subject of divisional application. The housing 1 may include the response unit 60 including correct and incorrect response indicates lamps of a separate question and answer teaching machine.