Frequency-variable sine wave generator
LM324
Oscillateurs
/
Oscillators
Électronique /
Electronic
In this project, you're going to build a CR oscillator that can change frequency.
When you finish wiring, turn power ON. You'll hear a tone of sine wave from the speaker. Rotate the control volume, and you'll sense that the frequency of the tone changes.
The OP amplifier U1A has a gain of 10, while the other OP amplifier U1B comprises a band pass filter.
The output of U1A is limited by two diodes, so that the limited sine wave is put through the band pass filter U1B.
The sine wave having been through U1B undergoes current amplification by the voltage follower U1C, before it passes through Q1 and then drives the speaker.
| Bill Of Materials For Frequency-variable sine wave generator | ||||||
| 11 Resistors | ||||||
| Quantity: | References | Value | ||||
| 4 | R1, R2, R4, R10 | 1k | ||||
| 2 | R3, R5 | 10k | ||||
| 1 | R6 | 150k | ||||
| 1 | R7 | 4K7 | ||||
| 1 | R8 | 1M | ||||
| 1 | R9 | 100k | ||||
| 1 | R11 | 47k | ||||
| 3 Capacitors | ||||||
| Quantity: | References | Value | ||||
| 1 | C1 | 100uF | ||||
| 2 | C2, C3 | 0.001uF | ||||
| 1 Integrated Circuits | ||||||
| Quantity: | References | Value | ||||
| 1 | U1 | LM324 | ||||
| 1 Transistors | ||||||
| Quantity: | References | Value | ||||
| 1 | Q1 | 2SC945 | ||||
| 2 Diodes | ||||||
| Quantity: | References | Value | ||||
| 2 | D1, D2 | 1N4148 | ||||
| 4 Miscellaneous | ||||||
| Quantity: | References | Value | ||||
| 1 | BAT1 | 9V | ||||
| 1 | LS1 | SPEAKER | ||||
| 1 | ON | OFF | ||||
| 1 | RV1 | 50k | ||||
