Pre-Amp + Tone Control with TDA1524A

This is a low noise and distortion pre-amplifier and tone control circuit in one module. Using a special IC TDA1524A, this simple circuit is easy to build and will drive most of power amplifier. Schematic diagram:

Mini FM Transmitter

This is a mini fm transmitter circuit. I think this is the simplest one. Simple, easy and of course… inexpensive… The supply voltage is between 1.1 – 3 Volts with power consumption is 1.8 mA at 1.5 Volts. This circuit should be able to cover  30 – 50 meters of range max. at 1.5 Volts.… Read More »

HiFi Audio Pre-amp

This is a HiFi pre-amplifier circuit diagram with low noise output. Very wide range frequency from about 10Hz until up to 100Khz  will be gained by this preamplifier for maximum audio performance. This circuit uses BC550C / BC560C transistors as active component. Use regulated power supply 15VDC for maximum result.

Ultrasonic Sensor Switch

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 »

Mini AM Transmitter

This is the simple and low cost AM transmitter schematic diagram built using transistor BC109C. The circuit is in two halfs, an audio amplifier and an RF oscillator. The oscillator is built around Q1 and associated components. The tank circuit L1 and VC1 is tunable from about 500kHz to 1600KHz. These components can be used… Read More »