Archive for the ‘Control and Monitoring’ Category
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 …[Read More]
Missing Pulse Detector Circuit with 555 IC
Missing pulse detector will receive a source of repetitive pulse in normal condition. The output of this detector circuit will be inactive for normal condition (output pin 3 of 555 IC will be high, turning off the LED indication). If now the input pulse is missing, delayed, or stopped, then the output of this detector …[Read More]
Waiting a call hold can be boring if there is only silence on the line. It’s a good thing to present an “easy music” in call hold, make a long waiting time feels much shorter. This simple circuit (consists of diodes, SCR, and some passive components) allows to place the caller on hold in one …[Read More]
Sound-Activated Lamp (Relay/Switch)
This simple circuit shown int the schematic diagram actives the switch using sound. We can use this circuit for various applications, such as automatic (sound-controlled) disco light or car’s LED light show. The Q1 amplify the audio from mic. The R1 is used to adjust the peak of signal to greater than about 0.7 volts, …[Read More]
Digital Encoder Circuit Using Stepper Motor
Using circuit depicted in the schematic diagram below, the direction and shaft rotation of stepper motor can be seen on the LED display. Alternative to digital rotation encoder as a digital encoder input, this circuit uses a stepper motor. Here is the schematic diagram of the circuit:
True Stereo Indicator Detects L-R Signal Difference
This true stereo indicator is different from what we usually find on FM radio receiver, which is usually a pilot tone detector. A stereo broadcast from FM radio station contain pilot tone, but a presence of pilot tone doesn’t necessarily a stereo broadcast signal since a mono FM transmitter ca broadcast pilot tone as well. …[Read More]
One Direction Motion Sensor
This is a one direction motion sensor circuit. This motion sensor circuit is used to detects an object passing in one direction, ignoring an object that going to opposite way. This circuit uses two sensors to identify the movement only in one direction. The basic principle of this circuit is simple, where one sensor is …[Read More]
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