“Hum” Remover

Here is the hum remover circuit diagram. “Hum” usually occured from live audio system, for example: input from microphone. Hum can be removed from an audio signal to get the maximum performance by mixing the actual hum with an antiphase hum in equal level. You can use any NPN transistor to support this circuit.

10 Dancing LEDs

This is the circuit diagram of dancing LEDs which consists of 10 units LEDs. The 10 dancing LEDs circuit works like a audio level meter. The LEDs will be dance sequence with the sound level that entering the microphone. Components list: R1_____________10K 1/4W Resistor R2,R3__________47K 1/4W Resistors R4______________1K 1/4W Resistor R5,R6,R7______100K 1/4W Resistors R8____________820R 1/4W… Read More »

100 Watt Inverter 12VDC to 220VAC with Mosfet

This is another 100 watt inverter circuit diagram. Built based on IC CD4047 and Mosfet IRF540, this inverter have ability to supply electronic device -which require 220VAC-  up to 100w from 2-3A transformer from 12V lead acid battery. In the circuit diagram we can observe that 12V battery is connecter to the diode LED and… Read More »

1.5 Watt FM Transmitter

This is a simple, well designed 1.5 Watt FM Transmitter circuit using power transistor 2N2219A. This circuit should be able to cover 1-2 KM range. It use +5-30V power supply to work. Refer to the above diagram, the input source is an electret condenser microphone (you may try to  use other input sources) and signal… Read More »

Sound Effects Generator (8 different sound) based IC HT2884

This is the circuit diagram of sound effects generator. All sounds in this circuit are generated by HT2884. The HT2884 is a CMOS LSI chip equipped with tone circuit, noise circuit, and other control logic to generate various sounds to be used in sound effects production. This IC features: single power supply (2.4V – 3.3V),… Read More »