Multitone generator circuit using CD4001
This multitone generator circuit has many applications but here it is shown as door indicators, generating a different tone for each door of our house. For example, you can generate:
– a high tone when the button on the front door of the house is activated.
– a low tone, when the button on the tailgate is activated and …
– a middle tone, when the side door switch is activated.
The diagram shows a multi-tone alarm generator circuit activated with pushbuttons. This circuit has three pushbuttons, each of which produces the generation of its own distinctive tone.
The circuit is a simple monotonous alarm generator system with three inputs. In it, two of the inputs of the CD4001 integrated circuit are connected as an astable multivibrator, and practically does not consume energy when inactive, consuming only a negligible leakage current.
But when a resistor is connected between pins 2 and 5 of the integrated circuit, it is activated and acts as a square wave generator.
Resistors used must have a value lower than the 2.2 megaohms that has the resistance R4, and the frequency of the tone is inversely proportional to the value of the resistance. With the indicated resistance values the circuit generates:
- a tone of 1500 Hz (high tone) approximately when S1 is pressed
- a tone of 800 Hz (mid-tone) when S2 is pressed and …
- a 450 Hz tone (low tone) when S3 is pressed.
The generated tones are easily differentiated. The power output of this circuit is about 11 watts. But the final value will depend a lot on the actual impedance values of the speaker and the power voltage being used.
List of components for Multitone generator circuit using CD4001
- 1 IC CD4001, 4 NOR 2 input gates (IC1)
- 1 NPN transistor, 2N3704 (Q1)
- 1 NPN transistor, 2N3054 (Q2)
- 1 470K resistor (R1)
- 1 820K resistor (R2)
- 1 resistance of 1.5M (R3)
- 1 resistance of 2.2M (R4)
- 1 10K resistor (R5)
- 1 100 ohm resistor (R6)
- 1 resistance of 1K (R7)
- 1 1000 pF capacitor (C1)
- 1 diode 1N4001 (D1)
- 1 speaker with 5 to 25 ohms
Note: The CD4001 pins 8, 9, 12, 13 are grounded