UM3561 - Simple Sound Effects Generator Circuit

This is a very simple. The IC UM3561 produces four differen sound effects, the output at Pin 3 being amplified by the transistor 2N2222. A 64 ohm loudspeaker can be substituted in place of the 56 ohm resistor and 8 ohm loudspeaker.Skema Rangkaian Sound Effects GeneratorThe 2 pole 4 way switch controls the sound effects. Position 1 (as drawn)...

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Op-Amp 6-Line Audio Mixer Circuit

As with any audio mixer circuit, a slight loss is always introduced. The final summing amplifier has a gain of 2 or 6dB to overcome this. The Input line level should be around 200mV RMS.Skema Rangkaian 6-Line Audio Mixer based Op-AmpThe mic inputs are amplified about 100 times or 40dB, the total gain of the mixer including the summing amplifier...

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Water Activated Alarm Using IC 555 Circuit

This Water Activated Alarm circuit uses a NE555 timer wired as an astable oscillator and powered by the emitter current of the transistor BC109C. Under dry conditions, the transistor will from have no bias current and be fully off. As the probes get wet, a small current flows Between the base and emitter and the transistor switches on. A...

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LM390 Simple 2-Way intercom Circuit

This is a very simple two way intercom circuit based on a LM390 audio amplifier circuit . the intercom circuit is a stand-alone electronic communications system intended for limited or private dialogue. For this circuit you can use a 8 ohms speaker, one for each station and require a 6 volts dc power supply. Gain control can be done by...

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Triangle and Squarewave Generator Using Op-Amp

The circuit shows a simple triangle and squarewave generator using a common LM1558 dual op-amp to produce very low frequencies to about 10 KHz. The time interval for one half cycle is about R*C and the outputs will supply about 10mA. Triangle amplitude can be altered by adjusting the 47k resistor and waveform offset can be removed by adding...

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