outlet from 34 low 34 to 34 high 34 this entire system for simplicity 39 s sake has been designated as 34 adc 34 in fig2 in case of a change of the input voltage between 0 v and 3 5 v successively one outlet a1 a8 is always activated as shown in fig5 to prevent the switching transistors t1 t8 to change over in sudden bursts the rc members r1 c1 r8 c8 have been inserted moreover as indicated in fig4 a sawtooth or triangle signal of about 10 khz is superposed on the analogous input voltage for example from a functional generator manufactured by wavetek indiana inc the maximum amplitude of the sawtooth or triangle is u2266 0 5 v for example 0 499 v whenever the dc voltage signal for example dc offset of the wafetek generators amounts to 0 v then there is a sawtooth or triangle signal at the inlet of the 3 bit adc 39 s of 0 499 v amplitude and of a frequency of 10 khz i e outlet a1 is activated whenever now the dc voltage or dc offset is increased to 0 2 v then the total voltage on which the sawtooth or triangle signal is superposed lies between 0 2 v and 0 699 v i e during 3 5 of the time outlet a1 and during about 2.