The impulse of a positive from an exit of the DD2 element will arrive also on a DD2 counter SR entrance (, however the counter will not change a state as on its entrance of R (the conclusion during a, the of the C6 condenser determined by a constant via the R26 resistor, is supported the high level of tension.
Through a resistive divider of R2-R3 on the shaper of rectangular executed on the DD1 and DD2 elements the pulsing tension with a frequency of 50 Hz arrives. From an exit, the shaper impulses move on entrances of DD1 and DD counters DD1 in common with the DD3 counter and the DD3, DD4 elements form the timer counting hour of time. For the purpose of some simplification of the scheme, the cycle is chosen to equal about 65 minutes that practically does not influence the mode of charging of the battery.
The DA2 comparator compares a on the not inverting which is proportional to a on the battery, with tension at the matrix exit. As soon as this tension is made even, the comparator will switch, and at its exit there will be tension of low level. The DD3 element also, and logical "1" from its exit will forbid operation of the counter DD Thus, on the inverting entrance of the comparator will be recorded, proportional to tension on the loaded battery room at the moment time.
If within the second hour the on the battery so that it will cause a DA2 comparator, at its exit tension of high level via the R26 resistor will nullify the counter DD Thus, tension condition demanded by the maintenance instruction of batteries on the battery within two hours in a row is satisfied.
Until the timer counted the set time interval, at the exit of an of DD4 will be present logical "0" and, therefore, on a of the DD3 element and an entrance of CN (the conclusion of the DD1 counter will be logical "1", forbidding operation of the counter. In an hour at the DD4 element exit tension of high level. The of DD3 will switch and will allow operation of the DD1 counter, and also the counter DD, with it, At the exit of a resistive matrix tension will start in steps increasing (in a step to entrance impulses). Its minimum size (at logical "0" at all exits of the counter it by the R19 resistor in the course of a, and maximum — DD1 is equal to supply voltage of, the DD All range of tension of a matrix is broken into 256 steps on. 18 mV.
When switching the comparator the logical Logical element DD "1" from its exit will arrive on an entrance (a DD1 element conclusion, on which second entrance (the conclusion to a is present logical "1". DD1, DD2 will switch, the high level of tension from a of DD2 via the VD12 diode will nullify DD1 and DD3 counters, returning them and the related logical of the DD DD4, DD1, DD2 in an state.