[en] The electrical signal measuring circuit incorporates an integrator circuit, operating at a first speed, and a signal transfer system to a second integrator after a determined time period, the second integrator working at a speed greater than the first. Instantaneous values from the first integrator are checked with a reference signal source. The intermediate components include an AND gate and transistors in parallel with a resistor in one lead of each, the resistors having different values. The transistors are typically FET's. (G.C.)