THREE IN ONE TONE GENERATOR:-

Various tone generator circuit is already published in www.electronicsproject.org. Now, here is unique tone generator circuit which produces three different type of sound according to input three different logic levels.

Circuit description:-

This circuit is designed around digital IC 7400 which is NAND gate. The working of the circuit is like the working principle of oscillator circuit, where frequency depends upon capacitors C₁ and C₂. The duty cycle of this circuit is 50%. The output is given to power amplifier circuit which further drive loudspeaker or head phone. For low frequency value of capacitor C₁ and C₂ must be high and vice-versa.

CIRCUIT DIAGRAM:-

PARTS LIST:-
Resistors (all ¼-watt, ± 5% Carbon)

R₁, R₄ = 1.2 KΩ

R₂, R₃ = 1 KΩ

R₅ = 10 KΩR₆, R₇ = 47 KΩ

Capacitors

C₁ = 100 kpF

C₂ = 220 kpF

C₃, C₄ = 10 kpF

Semiconductors

IC₁ = 7400 (NAND gate)

D₁, D₂ = 1N4148

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