Simple Door Open Alarm Circuit using Reed Switch uses reed switch which makes alarm sound when door opens. This simple circuit help protect door from people not allowed. It have reed switch, transistors, resistors, buzzer, diode and LED. Reed switch control power to alarm. Circuit Working: Parts List: Category Description Quantity Resistors 1k 1/4 watt […]
Simple FM Microphone Transmitter Circuit
FM mic transmitter is small device. It changes sound from mic into radio signal. FM radio can hear it in short distance. This Simple FM Microphone Transmitter Circuit uses one NPN BC547 transistor. Even it is small it can send FM signal pretty far. Circuit Working: Parts List: Category Description Quantity Resistors 330Ω 1/4 watt […]
How to Design Crystal Oscillator Circuit
To design Design Crystal Oscillator Circuit need know some basic things. Use crystal to make steady frequency. Choose right crystal and connect with other parts like resistor and capacitor. Be sure circuit give right signal for our device. Easy steps help us build good working circuit. Circuit Working: Let us learn about this circuit with […]
Simple Over Voltage and Reverse Voltage Protection Circuit
Our device is safe from bad voltage by using this Simple Over Voltage and Reverse Voltage Protection Circuit. This circuit uses P channel MOSFET FQP47P06 which better than only diode. Simple diode can stop reverse voltage but not protect from overvoltage or surge. Here the MOSFET and Zener diode give protection. Circuit Working: Parts List: […]
Tone Controller Circuit using IC TL072 Op-amp
Tone Controller Circuit using IC TL072 Op-amp changes treble and bass sound. It makes sound better and let us control treble and bass. Parts connect in order to cut or boost some sound frequencies. Circuit Working: Parts List: Category Description Quantity Resistors (All resistors are 1/4 watt unless specified) 1k 2 100k 2 10k 2 […]
Car Stereo Amplifier Circuit
Car Stereo Amplifier Circuit with IC TDA7297 is easy to build dual channel amplifier. It works with one 12V power and gives good power to 8 ohm speaker. With 17V it gives more power. Its made for radios and TVs but can be uses for many things. This circuit is good for audio system, midi […]