This is Vice Control Music Outlet circuit using SL517A, this electronic circuit project build a very easy. The circuit is shown in Figure, and it is composed of acoustic sensor, voice control IC, relay control circuit, song voice circuit and AC buck rectifier circuit.

Vice Control Music Outlet Circuit using SL517A:





Voice control IC uses SL517A which contains high-gain amplifier, bistable flip-flop and buffer output level, and it has two packages of dual in-line and black ointment. Its internal functional block diagram is shown as below.

2x300W or 600W Power audio Amplifier Circuit Diagram:




The circuit includes thermal shutdown circuitry that activates when the die temperature exceeds 150°c. CIRCUIT’s mute function, when activated, mutes the input drive signal and forces the amplifier output to a quiescent state. Maximum Output power @ 8ohms : 300watt. Absolute max power supply voltage :±38V to ±40V. Recommended power supply voltage :±30V to ±35V.

It is a very simple build a simple Audio-oscillator Circuit Diagram  Project. The circuit`s frequency of oscillation is/= 2.8/ [C1 x (R1 + R2)]. Using the values shown, the output frequency can be varied from 60 Hz to 20 kHz by rotating potentiometer R2. A portion of IC1`s output voltage is fed to its noninverting input at pin 3.

Audio Oscillator Circuit Diagram:



The voltage serves as a reference for capacitor Cl, which is connected to the noninverting input at pin 2 of the IC. That capacitor continually charges and discharges around the reference voltage, and the result is a squarewave output. Capacitor C2 decouples the output. 

Here is a very simple and easy to use audio amplifier using I.C BEL(Bharat electronics limited)1895 , a very common IC. This circuit can run on 3V to 6v , making it easy to use in pocket amplifier. Cost is under 25/-

Sooper Amplifier Using BEL1895 I.C:



 
Parts list:

BEL1895 I.C (DIP8),
C1 = 470uF/10V,
C2 = 1000uF/16V,
C3 = 220uF/10V,
C4 = 100uF/10V,
C5 = 4.7uF/10V,
C6 = 47pF,
C7,C8 = 1uF,
R1 = 47Ohm,
R2 = 470Ohm,
R3 = 100K,
R4 = 1Ohm,
R5 = 10K V/C,
speaker, etc…
Total cost is around 20-30 rupeess(INR) or 0.6USD.

Monolithic Voice Record-replay Intergarted Circuit QX-R42 can constitute a monolithic solid recorder and its sentence is input by users and played repeatedly.Please press button SA3 when you record and at the time,27 feet of the IC is in low PWL and voice signals enter storage unit via Microphnone,MIC.

Monolithic Voice Record-replay Intergarted Circuit Diagram:




Plesae loosen the button and it can play the voice after finishing recording.There are two palyback buttons.SA1 is low PWL triggering playback.SA2 caues tirggering playback by pulse falling.SA1 can be chosen and SA2 is not used when we choose playback button.When we choose to use other circuit'spulsetriggering but button and the pulse will be input IC's 24 feet and it constitute automatic playback mode.

LED is recording indicating light and it sparks during the recording process.R5 and R6 constitute automatic gain control net.R2 and C3 constitute analog signals which iuput and output coupling loop.Thus the 14th and 15th feet output playback signals and the speaker is drived to playback directly.