Patent GB-1164351-A (GB)
Title: Circuit Generating Apparatus.
IPC: H05K3/00
Filed: 1967-01-16
Abstract: 1,164,351. Circuit generating apparatus. INTERNATIONAL BUSINESS MACHINES CORP. 16 Jan., 1967 [17 Jan., 1966], No. 2154/67. Heading H1R. Patch panel wiring is automatically generated as the circuit to be wired is being drawn. Figs. 1A-1B show a portion of a format on which appears a drawing of an electronic circuit which includes a plurality of horizontal lines X1-XM and vertical lines Y1-YN, switches XM1, Y1M, ZM1 &c. and a plurality of electronic circuits C1-C4. The patch panel Figs. 2A-2B includes upper and lower planes 10, 12 respectively each having an X and Y line corresponding to those in the format and each junction of an X, Y line being connected to the corresponding junction in the other plane by a line Z. Each Z line includes a switch and each X, Y line includes a plurality of switches. Circuits C1-C4 are connected via a changeover switch to a summing or difference circuit SC, DC. By suitably closing selected ones of the X and Y switches in the planes and energizing selected ones of the switches 18 a desired circuit may be set up. This is done by placing the format on a board having pressure sensitive switches positioned at the points indicated by the dotted circles in Figs. 1A-1B, these switches comprising a substrate having a layer of conductive material thereon, an insulating spacer having a plurality of openings and a diaphragm having conductive segments on its underside adjacent to each of the openings in the spacer. A circuit is completed when the diaphragm is depressed bringing one of the conductive segments into contact with the conductive layer on the substrate. The pressure sensitive switches are activated by means of a ball point stylus 36, Fig. 4, which draws on the format the circuit to be connected in the patch panel and as the stylus moves over the lines on the format it causes the conductive segments of any pressure sensitive element in its path to be brought into contact with the common conductive layer. This causes a latching relay corresponding to the selected pressure sensitive element to be energized causing the contacts of the selected switch to be closed and remain closed in the patch panel. The activating circuit also includes pressure switch 50 in the stylus 36. Each plane 10, 12 is provided with a respective stylus so that when the connections to be made are on a particular plane the stylus corresponding to that plane is used to draw the circuit. An erase stylus is also provided which has an eraser substituted for the ball 42, this stylus causing any of the latch relays to be re-set when the stylus passes over the corresponding diaphragm. In order to make interconnections between the planes 10, 12 the corresponding conductive segment of the Z switch is touched by either the upper or lower stylus. After the circuit has been completed, the summing or difference circuits are connected in by means of the diaphragms adjacent the circuit elements using the corresponding upper or lower stylus. The board on which the format sheet is placed may be made transparent and a source of light placed under each X, Y line so that when one of the latches, Figs. 3A-3E (not shown), is energized the corresponding light source is also energized providing a visual verification of the circuit operation. A different colour light may be used to verify connections in different planes. The whole circuit may be reset by a reset switch. The upper and lower styli may be opposite ends of the same stylus.