Patent GB-589764-A (GB)
Title: Improvements in or relating to electromechanical calculating apparatus
IPC: G06F7/42
Filed: 1945-04-03
Abstract: 589,764. Electric calculating-apparatus. ERICSSON TELEPHONES, Ltd., and CROWE, D. C. April 3, 1945, No. 8186. [Class 106 (i)] Electric calculating apparatus is provided with means whereby the base or bases governing transfer from one order to another can be varied at will. The apparatus is divided into a number of groups corresponding to the different orders, each order comprising five sub-groups A-E of relay chains arranged on the binary system representing 1, 2, 4, 8, 16, respectively, so that the total capacity of each order is 31. The base of an order is selected by the operation of a key KBS and the depression of tens and unit keys corresponding to the base, after which addition and subtraction can take place with that base until the key KBS is operated again and a new base is set up. The operation in one order, irrespective of the base will first be described. Addition. The common start key KSC is depressed and remains depressed. The tens and units keys T, U corresponding to an entry are then operated, the tens key first to energize a relay RA, RB, RC according to whether the tens entry is 0, 1 or 2, and a relay TT, the selected units key connecting earth to one or more of leads A1-E1 according to which relay RA, RB or.RC has operated. The right-hand spring of each units key connects earth to relay SC, directly in the case of even keys and via metal rectifier MR in the case of odd keys. The earthed leads A1-E1 energize the associated U relays in the associated sub-groups. Taking sub-group C, Fig. 2, as an example, an earthed lead C1 energizes in turn relays UC, VC, XC and relay ZC, Fig. 3. Release of the numeral keys releases relays SC, RA-RC, TT, UC, VC, but XC holds and TC now operates. A further entry may or may not affect the subgroup C. If the entry is such as not to earth lead C1 and not to cause transfer to sub-group C, relay VC operates via contacts TC3, UC3 and SC1 and relay XC energizes so that the storage is unaffected. If entry into the C sub-group takes place, UC operates but not VC and transfer to relay VD of sub-group D occurs via contacts VC1, TC2, SU3. The circuit to XC, TC is broken at SC1 and these relays are left unoperated. If there is no entry, but transfer to the sub-group C with an existing storage there, both windings of relay VC energize, but as they are differentially wound, VC does not operate and relays XC, TC are left unoperated,. transfer taking place to sub-group D. If entry and transfer take place when sub-group C already registers an entry, VC operates on its right-hand winding and transfer to sub-group D occurs. Relays XC, TC also operate. When there is no storage and no entry, but transfer occurs from sub-group B, relay VC operates to operate relays XC, TC. With no storage and concurrent entry and transfer, both windings of VC energize so that VC does not operate. Transfer to the next sub-group occurs, but XC, TC are left unoperated. Subtraction. Depression of the numeral keys is preceded by depression of key KSU which operates relays SU, RU. The reversal of contacts SU3, Fig. 2, prevents transfer to the higher sub-group when an entry is made subtractively or a subtractive transfer is made into a sub-group already containing an entry. If a subtractive entry is made into an empty sub-group, relays UC, VC operate and via contacts VC1, TC1, SU3 transfer is effected to relay VD which energizes if previously inoperative and de-energizes if previously operative. In the latter case, transfer ensues to the next senior sub-group and so on until an energized V relay is found. Transfer and entry into an empty sub-group cause energization of both windings of relay VC which therefore does not operate and transfer to VD occurs over contacts VC1, TC2, UC2. Transfer and entry into a sub-group already containing an entry operates VC on its right-hand winding, XC and TC operate and transfer to VD occurs over contacts VC1, TC1, UC2. Zeroizing can be effected at any time by restoring key KSC. Variation of base. The base-setting key KBS is depressed to operate relay PT, Fig. 1, to connect relays PA-PE, Fig. 2, in the various sub-groups to leads A1-E1. The tens and units keys corresponding to the base are then depressed to operate the corresponding relays which lock up. Release of key KBS releases relay PT and leads A1-E1 are reconnected to the U relays. Addition takes place in the manner previously described, but when the total in the group exceeds or equals the base, an electrical-comparison of the P and V chains causes relay NX, Fig. 1, to operate through the earth on lead L6 being connected to lead L7, Fig. 2. Contacts NX1 connect earth to a transfer lead L10 (corresponding to L11 in Fig. 2) to the junior sub-group of the next higher order. Also, contacts NX2 connect earth to lead L9 to energize the Q relays in those sub-groups where the P relays are operated and an electrical comparison of the V and Q relays ensues to subtract the value of the base from that stored on the X chain and T chain. In the case of subtraction, if the quantity impressed on the U chain exceeds that registered, an attempted transfer over lead L12 by the sub-group E operates relay NX and contacts NX1 close to subtract one from the next higher order and contacts NX2 close to operate the appropriate Q relays, the SU and QU contacts being reversed from the positions-shown to cause addition. Contacts corresponding to NX1 in the highest order may operate an alarm when the capacity of the apparatus is exceeded or when the quantity registered becomes negative. Indicating. The amount on the register may be indicated by the depression of a key KDP, Fig. 1, which places earth on a line L1, Figs. 1, 3. The X relays of the various sub-groups control relays ZB, ZC, ZD, TN, TY, which together with relay XA control a set of switches to connect line L1 with appropriate lamps or other signal devices to indicate the number in that order. Contacts TY1-XA3 are provided if the total is to be transmitted to some other storage device in decimal form, or contacts TA5-TE5 if required in binary form.