Arrangement for generating pulse sequences

Apparatus for generating coded combinations of code pulses wherein each coded combination has P possible code pulse positions but only M(i) code pulse positions being occupied by coded pulses while P-M(i) code pulse positions are unoccupied;

• said apparatus comprising:
• a clock pulse source;
• a first pulse counter for counting the clock pulses from said clock pulse source, said first pulse counter including indicating means for giving an indication upon counting P clock pulses;
• a read-only-memory having ##EQU3## addressable cells subdivided into N sets of cells having consecutive addresses, wherein each set of cells is assigned to one of the coded combinations of code pulses and each cell of the set stores a number related to the position in the coded combination occupied by one of the M(i) pulses;
• a second pulse counter for counting identity pulses, said second pulse counter including output means for transmitting cell addresses to said read-only-memory in accordance with the instantaneous pulse counts accumulated therein;
• presetting means for selectively presetting said second pulse counter to store different initial counts;
• comparator means for comparing a first instantaneous count accumulated in said first pulse counter with the number stored in the addressed cell of said read-only-memory as represented by a second instantaneous count accumulated in said second pulse counter, said comparator means including means for transmitting an identity pulse to said second pulse counter each time a predetermined relationship exists between said first instantaneous count and said number;
• and a code pulse output means for emitting a code pulse each time an identity pulse is transmitted by said comparator means.