Monostable multivibrators


Posted on Feb 7, 2014

We`ve already seen one example of a monostable multivibrator in use: the pulse detector used within the circuitry of flip-flops, to enable the latch portion for a brief time when the clock input signal transitions from either low to high or high to low. The pulse detector is classified as a monostable multivibrator because it has only one stable s


Monostable multivibrators
Click here to download the full size of the above Circuit.

tate. By stable, I mean a state of output where the device is able to latch or hold to forever, without external prodding. A latch or flip-flop, being a bistable device, can hold in either the "set" or "reset" state for an indefinite period of time. Once its set or reset, it will continue to latch in that state unless prompted to change by an external input. A monostable device, on the other hand, is only able to hold in one particular state indefinitely. Its other state can only be held momentarily when triggered by an external input. A mechanical analogy of a monostable device would be a momentary contact pushbutton switch, which spring-returns to its normal (stable) position when pressure is removed from its button actuator. Likewise, a standard wall (toggle) switch, such as the type used to turn lights on and off in a house, is a bistable device. It can latch in one of two modes: on or off. All monostable multivibrators are timed devices. That is, their unstable output state will hold only for a certain minimum amount of time before returning to its stable state. With semiconductor monostable circuits, this timing function is typically accomplished through the use of resistors and capacitors, making use of the exponential charging rates of RC circuits. A comparator is often used to compare the voltage across the charging (or discharging) capacitor with a steady reference voltage, and the on/off output of the comparator...




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Amplifier Bridging
Universal motor control
Lc-checker
Ir Pulse To Audio Converter Circuit
1 KW Watt Meter
Crystal Oscillator Circuit
clock generator circuit
Low Loss Step Down Converter
Restoration of a Yamaha A-760 vintage integrated amplifier
Flyback Converters for Dummies
ISL43485 3.3V Half Duplex 30Mbps RS-485/RS-422 Transceiver
5474 tips
IN8510 and power motor driver circuit composed of DAC7520
Adjustable dual voltage power supply circuit



Top