Patent GB-1006161-A (GB)
Title: Improvements in or relating to teaching machines
Inventor: STEELE MALCOLM STUART
IPC: G09B7/08
Filed: 1963-01-16
Abstract: 1,006,161. Educational appliances. M. S. STEELE. March 17, 1964 [Jan. 16, 1963], No. 1950/63. Heading G5G. An electrically operable teaching machine of the multiple - choice question and answer type comprises means including a motor SDM, Fig. 1, and a film projection lamp PL for presenting student instruction items one at a time from a film carrying a plurality of such items, a set of keys A ... J and R, Fig. 1A, adapted to be selectively operated by a student to determine the next instruction item to be presented in accordance with the function of a selected key and means responsive to a machine control information item associated with a presented information item for modifying the function of at least one key. The modifications of the functions of the keys are introduced to prevent a student anticipating the function of certain keys associated with error or longer course of information and accordingly refrain from selecting the same although the instruction has not been fully assimilated. The machine has a number of keys A . . . J and R associated with a common latch bar LB maintaining any key depressed following operation thereof, the latch bar being released by energization of a latch bar solenoid LBS. In normal operation selection of keys A . . . H results in respective film advances of 1-15 frames in odd-numbered sequence, while I and J correspond to 19 and 1 frame film reverse. Key R is the return key and its function is to return the film to the frame previously displayed before such operation. The key functions determining the various degreee of forward or reverse film transportation are associated with a printed circuit commutator board including three arcuate elements PR1, 1, PR2 and PR3 together with an array of elements or segments AS . . . JS and RS and wiper contacts W1 . . . W4 associated with the elements PR1 . . . PR3 and the segments, respectively, and supported on a common radial arm RA. This arm is movable synchronously with the film transportation by a magnetic clutch CL rendered operative by energization of a solenoid LS, whereby for one film frame advance the arm is moved from alignment with segment RS to segment AS, for three frames advance the arm is moved from segment RS to BS, and so on. The arm RA is spring biased to return to alignment with the segment RS when the clutch CL is not energized. The machine further includes two photo-cells PC1 and PC2 which are activated in response to code marks located on each frame of the film representing said machine control information item for modification of the functions of the keys. Relays RL1 and RL2 are respectively associated with the photo-cells PC1 and PC2 and are each arranged for energization when their respective photo-cell is illuminated through a " transparent " code mark. The coding is of binary form and of the four possible combinations that with neither photo-cell activated is regarded as normal, whereby the key functions are as noted above. The remaining three codes are effective to modify the key func - tions from normal viz. activation of photo-cell PC1 with the resultant energization of relay RL1 inhibits the functions of keys A-H and J and associates key R with error whereby an error counter EC is activated to increase its count by one. Activation of photo-cell PC2 alone results in the inhibition of the key R and the function of key J is modified to one frame advance instead of one frame reverse and is associated with error. Lastly activation of both photo-cells inhibits the functions of keys A ... H and R and modifies key J function to one frame advance with error. The function modifying role of the photo-cells PC1 and PC2 may be dispensed with by opening a code release switch CR. In operation of the machine, closure of an ON/OFF switch S1 energizes conductors 56R, 54BL from a mains supply 240 v. A.C. indicated by terminals L, N, E whereby the secondary of winding of transformer TF1 produces a 24 v. A.C. supply. A 30 v. D.C. negative supply is derived via diode D1 and capacitor C1 and a 27 v. D.C. positive supply via conductors 10VL, 10WH, diode D4 and capacitor C4. Closure of the switch S1 also illuminates the projection lamp PL from the mains via conductors 46BL, 57BL, 47BN and resistor R4. The 24 v. A.C. supply energizes relay R3 via conductor 10VL to ring PR2, wipers W2, W4, segment RS and conductor 21VL to the relay. The clutch CL is energized by the 30 v. D.C. supply through normally closed contacts RL7/1 and conductor 40VL. Assuming normal function of the keys, i.e. no photo-cell active, depression of key A applies the 24 v. A.C. to associated switch contact T through conductor 33GY and normally open contacts R3/2 to energize relay RL4 which opens its normally closed contacts RL4/1 to break a shunt across resistor R5 which then acts to reduce the intensity of the projection lamp PL. Additionally contacts RL4/5 open to disconnect the 30 v. D.C. supply through conductors 52GY and 27GY to prevent photo-cell circuit operation during film transportation, which is subsequently initiated by the application of the main supply through normally open contacts RL4/1, normally closed contacts RL5/1 and conductor 2GY, mieroswitch MS, conductor 1GY, normally closed contacts RL6/1 and conductor 43VL to the sprocket drive motor SDM. At the same time the main supply is also applied from contact RL5/1 via 42VL to the breaking solenoid BS which is released and spooling motors SM1 and SM2. As soon as the wiper W4 moves from contact with the segment RS the relay R3 is de-energized and when the wiper is aligned with AS the 24 v. A.C. supply from the ring PR2 is applied to the segment AS, conductor 20 WH, contacts L, M, conductor 29GY and normally open contacts RL4/2 to energize the stop relay RL5, whose contacts RL5/1 open to stop the motors and terminate the film transportation. Simultaneously the latched key A is released by the latch bar LB by the energization of the solenoid LB5 through normally open contacts RL5/2 and conductor 32GY and the relay RL4 is de-energized as the switch contacts S, T open. Accordingly contacts RL4/2 close to de-energize relay RL5 and the photo-cell circuits become once more effective through contacts RL4/5. In use the various modifications of the key functions are limiting the student's choice of action, viz. when he commits a minor error by selection of a particular answer, an answer implying such an error may be followed by a frame requiring the student to depress the return key R and reconsider his last selection of answer and key. Such a frame may be accompanied by code marks causing activation of photo-cell PC1 alone whereby all keys are inhibited except R. In the event of selecting an answer and key corresponding to a major error, the next frame may initiate a lengthy teaching sub-routine and be accompanied by code marks causing activation of both photo-cells. This frame is accordingly associated with little choice of action as the keys A ... H and R are inhibited and the operation of the key J provides one frame advance with error counter EC operation. In other embodiments (not shown), the film may be replaced by magnetic tape and the instruction items presented orally, or a combined oral and visual presentation may be desirable.