Simple Adjustable Frequency Square Wave Generator Circuit is easy and flexible. It is used in signal processing, modulation and in many projects. Here we see variable frequency oscillator using 555 timer IC which makes square waves and where user can change frequency. 555 works in astable mode and turning potentiometer changes output speed. Circuit is […]
Simple Sawtooth Wave Generator Circuit
Simple Sawtooth Wave Generator Circuit is used in oscilloscope, TV, function generator and PWM. IC 555 is very common and is easy to make sawtooth. Voltage goes up slow and drop fast in sawtooth shape. Frequency changes with potentiometer. Circuit works with 5V to 15V. Circuit Working: Parts List: Component Value/Part Number Quantity Resistor 2.2k […]
6V DC Motor Speed Controller Circuit using IC CD 40106
This 6V DC Motor Speed Controller Circuit using IC CD 40106 controls 6V DC motor speed. Change speed by change in duty cycle of input voltage. Circuit is cheap, easy, good for toy motor, small fan and blower. Main part of this circuit is IC CD 40106 Schmitt trigger inverter which makes PWM signal. PWM […]
Transistor Based Stepper Motor Drive Circuit
Stepper motors are good for robots, CNC, automation and to move very exact. Transistor Based Stepper Motor Drive Circuit run unipolar motor with logic gates and transistors. It use four 2N2222 to control motor windings, two NOT gates, one XOR gate and to read 2-bit control to turn ON 4 windings. Circuit needs parts like […]
Relay Connections at the Collector and Emitter Sides of a Transistor: Which is Better?
Relays are very important in electric circuit for switching ON/OFF. They control big power load using small signal which is very useful. Transistors are often used to control relay for better switching and for less power loss. Relay coil can be ON transistor collector side or emitter side. Choice changes how circuit works with each […]
Temperature Based DC Fan Controller Circuit using Transistors
Temperature Based DC Fan Controller Circuit using Transistors turns ON when hot, stops overheating and saves energy. Thermistor checks temperature and runs fan as needed. The circuit works on 12V battery or 12V power supply. Circuit Working: Parts List: Component Type Value Quantity Resistors (All resistors are 1/4 watt unless specified) 1.5k 1 1k 1 […]