### APTE-5111-R: Electronic Parts and Specifications The **APTE-5111-R** is an **Electro-Magnetic Transducer (Buzzer)** designed for surface mount (SMD) applications. It is widely used in consumer electronics, medical devices, and industrial equipment for audible notifications. --- ### 1. Key Technical Specifications The performance of the APTE-5111-R is defined by its electrical input and acoustic output requirements: | Feature | Specification | | :--- | :--- | | **Rated Voltage** | 3.6 Vo-p | | **Operating Voltage** | 2.5 ~ 4.5 Vo-p | | **Mean Current** | Max. 100 mA | | **Sound Pressure Level (SPL)** | Min. 85 dB (at 10cm) | | **Resonant Frequency** | 2,700 Hz | | **Operating Temperature** | -30°C to +70°C | | **Mounting Type** | Surface Mount (SMD) | --- ### 2. Internal Electronic Components The APTE-5111-R is a **passive transducer**, meaning it does not have a built-in oscillation circuit. It requires an external square wave signal to operate. Its internal construction consists of: * **Electromagnet (Coil):** A copper wire coil wrapped around a core. When current passes through, it generates a magnetic field. * **Permanent Magnet:** Provides a static magnetic field that interacts with the electromagnet. * **Vibrating Diaphragm:** A thin metal plate (usually iron or a magnetic alloy) that is physically moved by the alternating magnetic fields. * **Housing:** A heat-resistant LCP (Liquid Crystal Polymer) plastic case designed to withstand reflow soldering temperatures. --- ### 3. Circuit Integration Since this is a passive component, the electronic design must include a driving circuit. #### Drive Circuit Requirements: * **Signal Type:** Square Wave (50% Duty Cycle). * **Frequency:** Should be set to the resonant frequency (**2,700 Hz**) for maximum volume. * **Switching Component:** Typically driven by an NPN transistor or a MOSFET controlled by a Microcontroller (MCU) PWM pin. * **Protection:** A flyback diode is often recommended in parallel with the transducer to protect the switching transistor from inductive voltage spikes. ```c // Example Pseudocode for driving the buzzer (2700Hz) void setup() { pinMode(BUZZER_PIN, OUTPUT); } void loop() { // Generate 2700Hz tone tone(BUZZER_PIN, 2700); delay(500); noTone(BUZZER_PIN); delay(500); } ``` --- ### 4. Application Considerations * **Soldering:** Being an "R" suffix part (RoHS compliant), it is designed for lead-free reflow soldering. * **Polarity:** The device is polarized. The positive (+) terminal must be connected to the driving source correctly to ensure the diaphragm moves in the intended direction for optimal sound. ---