Audio Memo Alert Circuit

This device prevents paper notes and memos from being overlooked. A paper note placed between two fingers made of a conducting material (metal or conductive plastic) breaks the circuit, allowing pair 1 of Ul-a to go high. This causes Ul-c and Ul-d to act as an oscillator, pulsing piezo buzzer BZ1.

The device operates on a simple yet effective principle utilizing a conductive switch mechanism. When a paper note is inserted between two conductive fingers, the electrical circuit is interrupted, triggering a change in voltage that is detected by operational amplifier Ul-a. This amplifier is configured as a comparator, where the input from the conductive fingers determines the output state. When the circuit is broken, the output of Ul-a transitions to a high state, indicating that a note is present.

The high output from Ul-a is then fed into a pair of additional operational amplifiers, Ul-c and Ul-d, which are configured to function as an oscillator. This oscillator generates a square wave signal at a specific frequency, which is then used to drive the piezo buzzer BZ1. The pulsing of the buzzer serves as an alert mechanism, ensuring that the presence of the note is not overlooked.

The circuit design may include additional components such as resistors and capacitors to stabilize the oscillation frequency and manage the power supplied to the buzzer. The choice of conductive materials for the fingers is crucial, as it must ensure reliable circuit interruption while being sensitive enough to detect the presence of a paper note.

Overall, this device combines simple electronic components to create an effective reminder system, enhancing the visibility of important notes and memos through auditory signals. The schematic would typically include the operational amplifiers, the buzzer, and the necessary passive components to complete the circuit functionality. This device prevents paper notes and memos from being overlooked. A paper note placed between two fingers made of a conducting material (metal or conductive plastic) breaks the circuit, allowing pair 1 of Ul-a to go high. This causes Ul-c Ul-d to act as an oscillator, pulsing piezo buzzer BZ1.