Tag «Timer»

LT1016 – LS74121 Voltage Controlled Pulse Width Generator/ Monostable Multivibrator

Monostable multivibrator poduces a fixed pulse width when receiving a trigger signal on its input. The pulse width of the output is fixed regardless of the input pulse duration/width. In practical application, the width of the output pulse is determined by choosing the right components values for certain application. With this circuit schematic diagram, we …

Touch Switch Monostable/Timer with 555 IC

A schematic diagram of a touch switch circuit is shown below. This circuit consist of timer, one shoot multivibrator and touch terminal. As timer, this circuit uses 555 timer which is connected to one-shot multivibrator. The touch terminal is used to trigger this circuit. The output of this  circuit can be used to drive a …

Versatile Discrete Monostable Multivibrator

This is a versatile discrete monostable circuit. This circuit consist of 2N3819 JFET and 2N3704 transistors. This monostable multivibrator circuit  has additional input to enable or inhibit the function at any time without causing output pulse. The input of this circuit accept a standard digital IC voltage levels. Here is the schematic diagram of the …

555-IC Timed Beeper/Alarm

This is a simple circuit of beeper using 555 timer. This circuit can be employed to energize lights, horn, or other signaling device at any desired interval when the mercury switch is triggered. Since the current handling capability of mercury switch is not so high, an SCR is used to handle current drawn by the …

Long Period SCR Timer

This is a SCR timer circuit. Here, SCR is used to drive the final actuator, the buzzer.  The time constanst of this circuit is determined by  R1 and C1. The buzzer will sound when C1 charges up to a desired level, it will cause the Q1 to conduct and triggers SCR1.  The use of FET …

Single Transistor Blocking Monostable

Below is  a schematic diagram of blocking monostable circuit. The normal state of the transistor is off because the 10 k resistor has been removed. The conduction will be started using a positive pulse at node “a” and the transformer will do the rest. The transistor will again be turned off (by a hefty …