## HAP-32-R: Electronic Parts & Specifications The **HAP-32-R** is a high-performance **Piezoelectric Transducer (Buzzer)** commonly used in industrial alarms, medical devices, and automotive warning systems. Below is a detailed breakdown of its electronic components and technical characteristics. --- ### 1. Core Electronic Components A piezoelectric buzzer like the HAP-32-R consists of three primary internal elements: | Component | Function | | :--- | :--- | | **Piezoelectric Ceramic Disk** | The "heart" of the device. It expands and contracts when an electric field is applied (Inverse Piezoelectric Effect). | | **Metal Vibration Plate** | Usually made of brass or stainless steel. The ceramic disk is bonded to this plate to amplify sound waves. | | **Resonant Chamber (Housing)** | The plastic casing (often NORYL or ABS) designed to create acoustic resonance, increasing the decibel output. | | **Terminals/Pins** | Two conductive pins (usually through-hole) for PCB mounting and electrical connection. | --- ### 2. Technical Specifications The "R" suffix typically denotes a specific revision or **RoHS compliance**. Here are the typical electronic parameters for the HAP-32 series: | Parameter | Specification (Typical) | | :--- | :--- | | **Operating Voltage** | 1.0 ~ 30 Vp-p (Square Wave) | | **Rated Voltage** | 10 Vp-p | | **Current Consumption** | Max 5mA at 10 Vp-p | | **Sound Pressure Level (SPL)** | Min 85 - 90 dB (at 10cm / 10 Vp-p) | | **Resonant Frequency** | 2,500 Hz ± 500 Hz | | **Capacitance** | 25,000 pF ± 30% (at 120Hz) | | **Operating Temperature** | -20°C to +70°C | --- ### 3. Driving Circuit Requirements Unlike an "Indicator" (which has internal circuitry and only needs DC power), the **HAP-32-R is a Transducer**. This means it requires an external oscillating signal to produce sound. #### Example Driving Circuit (Simple NPN Switch) ```c VCC (e.g., +5V) | [HAP-32-R] | +------- C (Collector) | Signal ---[ R ]--- B (Base) [NPN Transistor] | +------- E (Emitter) | GND ``` * **Signal Type:** Square wave (PWM). * **Frequency:** Should match the resonant frequency (~2.5kHz) for maximum volume. --- ### 4. Key Physical Features * **Mounting:** Through-hole (DIP) pins for PCB soldering. * **Polarity:** Generally non-polarized, but often marked for consistent phase in multi-speaker setups. * **Construction:** Sealed base for wave soldering compatibility (depending on the specific batch).