FM Receiver with TDA7021T

This is the circuit diagram of mini FM receiver that build based on single FM IC TDA7012T. Components List: R1 = 8kΩ2 R2 = 10kΩ R3 = 390Ω C1,C3 = 10nF C2,C6,C9,C16 = 100nF C4 = 33pF C5 = 25pF trimmer (Murata type TZB4Z250AB10R00) C7,C10 = 1nF5 C8 = 820pF C11 = 1nF C12 =… Read More »

One Chip AM Radio Receiver

Here is the AM Radio receiver circuit diagram based on old single IC MK484. Components List: R9, R10_________ 6R8 R6_____________ 100R R3_____________ 1K R1_____________ 4K7 R7_____________ 5K6 R4_____________ 10K R2_____________ 100K R5_____________ 150K R8_____________ 820K Pot_____________ 10K log pot Coil & ferrite bar set C7______________ 470p ceramic C, C4, C5, C6_____ 470nF monoblock C2______________ 100nF… Read More »

Active FM/AM/SW Radio Receiver Antenna

This is an active FM/AM/SW radio receiver antenna, can be used for FM radio receiver, AM radio receiver and SW (shortwave) radio receiver. This circuit use active component JFET VHF Amplifier MPF102 to boost the radio signal. It use 9VDC supply to work. On the shortwave band this active antenna is comparable to a 20… Read More »

4W Audio Amplifier using Transistor TIP41

This 4W Audio Amplifier circuit is powered by 2 pieces of transistor TIP41. The circuit is very simple and incorporates darlington output transistors that will provide more than enough output current than is needed to drive a 3-ohm speaker. The 4W audio amplifier circuit is very simple and incorporates darlington output transistors that will provide… Read More »

Home Telephone Call Recorder

This is the circuit connection of home telephone call recorder that uses very few components. In order to understand its working, we must first have the basic knowledge of standard telephone wiring and a stereo plug. In some countries, landline telephones primarily use RJ11 wiring, which has two wires—tip and ring. While tip is the… Read More »

Ultrasonic Distance Detector / Sonar Ranging System

This is the ultrasonic distance detector or sonar ranging system which can be used for general purpose. There are kit version available on the market, but of course the price is 3x more expensive than if you build your own sonar ranging system. Some application may use this circuit such as robot applications, body height… Read More »