Free Circuit Diagram

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 [...]

Twisted-pair wiring is a wiring technique that usually used for in-building data communication. Compared to conventional coaxial-cable, this technique offers substantial cost saving, for video transmission on the same medium. A differential driver is used to launching a baseband camera signal to twisted pair. Twisted pair exhibits a roll-off characteristic that need equalization to [...]

The transmitters that either working in FM or in AM is familiar. This is transmitters circuit that can transmit both FM and AM signal simultaneously at two different frequencies FM in 100Mhz and Am in 20 MHz. Here is the circuit: To transmit the FM signal, this circuit uses the 5th harmonics [...]

This antenna booster circuit can be used to amplify the weak signal received by the antenna.  Antenna for AM/FM is usually not tuned for the optimal dimension of 1/4 wavelength, since we prefer small portable size. This untuned antenna has very low gain, so the antenna booster circuit here is very helpful in getting better [...]

RCV420 is a special function integrated circuit chip for 4-20mA current loop receiver. RCV420 provide complete 4-20mA to 0-5V conversion, with 0.1% overall accuracy, 86dB CMR, and ±40V common-mode input range. This IC chip is suitable for many applications: PROCESS CONTROL INDUSTRIAL CONTROL FACTORY AUTOMATION DATA ACQUISITION SCADA [...]

For you who has failed to build  radio transmitters, this circuit worth a try. This circuit uses 74HC14 hex Schmidt trigger as the oscillator, and you can choose to use capacitor for low cost goal or quartz  crystal for better stability. For quartz crystal, you can choose any frequency between 00.7-1.6MHz, but around 1.6MHz is [...]