Multivibrators and 555 Timer Questions

• When extremely critical timing is required, a quartz crystal can be used.
• A comparator simply outputs a HIGH or LOW based on a comparison of the voltage levels at its input.
• When the 74123, a retriggerable monostable multivibrator device, ends its timing cycle it must be started all over again.
• Timing accuracy of more than eight significant digits can be easily achieved by using quartz crystals.
• The 74S124 TTL chip is a voltage-controlled oscillator that will generate a specific frequency at Vout.
• A multivibrator is a circuit that changes between two digital levels on a continuous, free-running basis or on demand.
• A monostable multivibrator is commonly called a two shot.