Free Circuit Diagram

ROHM (www.rohm.com) is originally a resistor producer company, but finally expand their business and produce monolithic IC, and this one used in our circuit is the example. The internal structure of this FM transmitter integrated circuit consist of stereo modulator that creates a stereo composite signal, an FM modulator that modulate a carrier frequency with [...]

This FM transmitter circuit is small, similar to our previous single chip FM  transmitter, but this FM transmitter is monophonic. You can see in the circuit’s schematic, the left and right signals is mixed before modulate the radio frequency. Here is the schematic diagram of the circuit:   The core of this [...]

Please be warned if operating this circuit might violate the regulation of your country, because this FM transmitter circuit radiate strong radio frequency to the environment. This wireless microphone is very sensitive, pick up every sound in the 20m radius, and transmit the radio signal up to 2 kilometers in open air. Here is the [...]

TDA 1072AT is a special purpose integrated circuit for AM radio receiver from Philips Semiconductors. The integrated circuit is designed for mains-fed home receivers and car radios. The voltage-controlled oscillator provides signals with extremely low distortion and high spectral purity over the whole frequency range even when tuning with variable capacitance diodes. RF radiation and [...]

This is a FM Transmitter circuit. This circuit uses logic gates. This transmitter circuit has a RF oscillator. This oscillator uses 10.7Mhz ceramic filter and inverter N2 to drive the parallel combination of N4 to N6 through N3. Here is the circuit: The output impedance will be low because these inverters are [...]

This wireless microphone circuit uses only a single transistor, with few additional passive components. This FM transmitter is very compact and need only a single cell 1.5Volt battery, even works on 1.2V rechargeable battery. Here is the schematic diagram of the circuit: The transmission range could be between 30-50m radius in open air, [...]