Using electronic diagram below can be built complementary electronic buzzer ring. This bell buzzer sounds after it was released button ring. Its required energy is stored in capacitor C2 whilst the ringer button is pressed. This adds a small task (and brief) adapter ring. At the same time, ensure blocking of T1 T2. Release the button, T1 and T2 locks begins to run. While there task C2 buzzer will sound. Sound duration depends on the value of C2 (the higher the value, the longer it sound).
This signal generator provides a sinusoidal output signal with a frequency of 440 Hz, at two voltage levels. Power can be made with a voltage between 1.5 V and 16 V. IC1a works as wave generator, the values of R4 and C1 determine the frequency of tipping the AO output. Potentiometer P1 allows to obtain a perfectly rectangular signal (setting can be done by listening and adjusting for low distortion signal).