This circuit reproduces the dial noise in a small speaker. The transistor can be a general-purpose type. We found it in an 80's Electronic Design.
Although the TDA1023 integrated circuit is no longer very common in our market, it can be used in...
June 2017 - The new ROHM Low Dropout Voltage Regulators (LDOs) for 3.3 V or 5.0 V high accuracy...
Depending on the key pressed, this oscillator produces a different tone, set in the corresponding...