Nonsymmetric multivibrators with an auxiliary RC-circuit

The paper describes the design of nonsymmetric multivibrators. These multivibrators include a large capacitor which is charged by a current source and discharged periodically by the comparator controlled switch. The distinctive feature of these multivibrators is an auxiliary RC-circuit of a small time constant which is connected between the large capacitor and the comparator. The voltage at the output of this auxiliary circuit follows the voltage at the large capacitor during the first quasistable state (space). The recharge of the small capacitor in the auxiliary circuit is used to determine the duration of the second quasistable state (mark). Three modifications are considered. If the space/mark ratio is small (¿10) the additional buffer amplifier is inserted between the large capacitor-and the auxiliary RC-circuit. For medium (¿ 100) space/mark ratio multivibrators the buffer amplifier is omitted and the capacitor in the auxiliary RC-circuit absorbs the functions of the large capacitor (which can be omitted also). For large (¿1000) space/mark ratio the auxiliary RC-circuit is connected to the large capacitor directly. The calculation of both quasistable state durations is given and useful design relationships are established. An example of the multivibrator for different (9, 99 and 999) space/mark ratios is given.