Electric puke code modulation encoding arrangements

Claim 1

An electric encoding arrangement for a pulse code modulation transmission system comprising: (A) means periodically to sample an electric input signal and to store temporarily a voltage proportional to the value of that input signal during the sampling period, (B) a capacitor, (C) means to charge said capacitor to a first charged state from a reference level for a first predetermined period at a rate determined by said stored voltage, (D) means to discharge said capacitor to said reference level from said first charged state, (E) means responsive to the capacitor discharge time from said first charged state and, hence, the value of charge on the capacitor in its first charged state to derive a first digitally coded signal denoting in which of a plurality of contiguous ranges of voltages the stored voltage in the first charged state lies, (F) means to charge the capacitor to a second charged state from a reference level at a rate determined by said stored voltage, the second charging being for a second period selected from a plurality of predetermined periods in dependence upon the segment in which said first stored voltage lies, (G) means to discharge said capacitor from said second charged state to said reference level after said second predetermined period, (H) means responsive to the capacitor discharge time from said second charged state and, hence, to the value of the charge on the capacitor in its second charged state derive a second digitally coded signal which represents the value of charge acquired by said capacitor at the end of said second predetermined period, (I) the complete coded signal representing the value of said stored sample voltage comprising at least parts of said first and second digitally coded signals.