This is a very simple FM receiver which build based on one transistor only. No chip or another active component. The output is connected to earphones, you need an amplifier circuit if you want to listen the radio with a loudspeaker.
This the Good Quality FM transmitter for your stereo or any other amplifier gives you a pretty good signal strength up to a range of 500 metres having a power output of about 200 mW. This circuit can be operated with a 9V battery. The audio-frequency modulation stage is constructed close to transistor BF494 (T1),… Read More »
This is a mini FM transmitter built and powered using 2 transistors, designed by Tony van Roon. This small transmitter is simple to build and its transmissions could be picked up on any common FM radio. It possesses a range of approximately 1/4-mile (400 meters) or even more, depending on the line-of-sight, obstructions by big… Read More »
The following diagram is the circuit diagram of voice transmitter which use FM signal carrier to transmit the vioce signal to the FM receiver device. Components List: R1 = 4.7K R2 = 330 ohm C1 = 0.001uF (1nF) C2 = 10-40pF C3 = 4.7pF Q1 = 2N3904 L1 = see text Misc = Electret mike,… Read More »
Simple and easy build of sensitive FM transmitter circuit. The circuit only requires 2 transistors to work. *L1 = 0.1 Uh, 6 to 8 turns of 22 ga. hookup wire close wound around a 1/4 inch diameter non-conductive core such as a pencil Circuit Notes: Typically the default for the capacitors model is ceramic, preferably… Read More »
This is the active FM receiver antenna amplifier, used to boost the FM signal catch by the antenna, you may call circuit “FM antenna booster”. By working with only a small handfull of parts you can assembled this kind of reliable FM amplifier circuit. It runs with only 1 UHF/VHF type transistor, MFE201. This amplifier… Read More »
This circuit is a wireless car alarm system that is built using two circuit modules, namely modules of transmitter and receiver modules. This circuit works on FM radio waves. Car alarms can be used on vehicles that have a 6-12VDC power supply. You can use the voltage stabilizer if your car power supply is too… Read More »
Here is the circuit diagram of ultrasonic sensor switch. There are many methods of wireless switching such as by using infrared, AM/FM signal, bluetooth, etc. This is an alternate wireless switching by using ultrasonic sensor. The distance of switching range should be more than 10 meters. This circuit produces and transmits ultrasonic sound of frequency… Read More »