Last Updated on March 16, 2024
This circuit constructed by using tone encoder IC TCM5087. This can be used for to produce tones that same to the telephone dialling tone.
This circuit produce high band tone and also low band tone through row and column pins. The switch s1 to s12 are connected with row and column line of integrated circuit TCM 5087.
Components List
| S.No | Name | Quantity |
| 1. | IC TCM 5087 | 1 |
| 2. | Transistor BC547 npn | 1 |
| 3. | Resistor 220Ω | 1 |
| 4. | Push to on switch | 12 |
| 5. | Loud speaker 8Ω | 1 |
| 6. | Xtal-crystal 3.579MHz | 1 |
| 7. | Connecting Wires | As required |