DIGITAL FREQUENCY METER Russian patent published in 1997 - IPC

FIELD: instruments, in particular, measurement of low and very low frequencies using functional encoding of period when hyperbolic function f_x≠1 is used. SUBSTANCE: this function can be represented as follows , if U_i≅ 0,, then V₁; if U_i≥ 0,, then V₂. Device has input time interval generator 2, which has reference oscillator 3, AND gate 4, subtraction counter 5 which has setting code bus 6, RS flip-flop 7, AND gate 8, first and second univibrators 9, 10, OR gate 11, first binary counter 12 with setting code bus 13, second binary counter with setting code bus 15, first binary combination adder 16 which has logical zero bus 17 and logical one bus 18, second binary combination adder, memory register 20, which has setting code bus 21 and sign bit 22, AND gate 23, result binary counter 24 which has setting code bus 25, digital indicator 26. EFFECT: increased precision of measurement. 2 cl, 6 dwg