GB553947A - Improvements in electrical means for the multiplication of variable quantities - Google Patents

Abstract

553,947. Electrical multiplication. TELEFONAKTIEBOLAGET L. M. ERICSSON. Aug. 28, 1941, No. 11003. Convention date, July 5, 1940. [Class 106 (i)] In means for the multiplication of up to five factors, of which not more than two are represented by electrical voltages and the remainder, which are introduced as positions along up to three adjustable impedances, are represented by mechanical quantities, the resistance distribution of at least one of the impedances is non-linear, while a zero-indicating instrument controlling a wiper along another adjustable impedance is connected in a zero-circuit between said wiper and a position along one of the'aforesaid impedances, said impedances and the given voltages being arranged and connected to one another in such manner that a product is obtained as a position along the impedance controlled by the zero-indicating instrument. Functions of the five factors are entered as a pair of voltages E<SP>1</SP>, E<SP>2</SP> or E<SP>11</SP>, E<SP>12</SP>, and three variable impedances Y<SP>1</SP> Y<SP>2</SP>, Y<SP>3</SP>, or y<SP>11</SP>, Y<SP>12</SP>, Y<SP>13</SP>. The impedances are constructed with a high number of contact positions. A zero-indicating instrument N<SP>1</SP> or N<SP>11</SP>, for instance, a sensitive polarized relay preferably without a neutral position working with a servo-instrument varies the impedance Y4 or Y<SP>14</SP> for zero current. The solution of the problem is a function of Y' or Y14. The device may be used for the solution of problems in which the factors are continuously varying. The impedances may be variable condensers for use with alternating current.