1500LEAX ALGEHUA AND CIUCUIT DESIGN 301 



/?, r, D and E relays. In comparison to this total of five relays and two 

 codes the cii-cuit in present iis(> in the latest crossbar system re(niii-es ten 

 relays and s(>\'en codes. 



AN ALTERNATE DESIGN OF THE I'ULSK DIVIDKK 



To ilhisti-ate th(> application of aiji;cl)ra whei'e the ai)pai'atus conlem- 

 plated i:)uts less premium on contact minimization i)iit more on stand- 

 ardization and winding minimization, certain modifications of the 

 l)roposed circuit are considercMl. 



In the (>\-ent that new apparatus developments make possible the 

 construction of relays that meet the necessary speed reciuirements even 

 thou,i>;h windint;- impedance is increased, it appears possible (if the pulse 

 (li\-ider is ledesigned) to use only one code having a single winding for 

 all fi\-e relays. The use of added contacts might be allowable if the new 

 type of re-lay carries more springs than the present relay. 



The redesign of the pulse divider to use single windings can be accom- 

 plished i)y manipulation of the basic algebraic expressions derived earlier 

 for the pulse divider. 



Thus for the A relay 



/(.4) = {U + B'){A + LB') 



= [U + B'][A + B'{L + B)] (11a) 



By attempting to manipulate the B relay control circuit into the same 

 form, one obtains 



f{B) = (L + A){B + L'A) 



^ (L + A){L' + B){A + B) (3b) 



= [U + B][A + BL] (3b) 



= [U + B][A + B{L + B')] (11a) 



The schematics represented by the above algebraic expressions are 

 shown in Fig. 8a and 8b. The circuit of Fig. 8c is obtained by combining 

 the first two circuits so that only a single transfer is needed on the L 

 relay. Note however that it is necessary to make the lower tw^o B trans- 

 fers have continuity action to insure proper functioning. Fig. 8d shows the 

 pulse divider drawn in conventional form. 



CONCLUSION 



As far as is known, the dial pulse (-ounting and translating circuit 

 described herein requires fewer relays than any other circuit with similar 



