The **P-213N-R** is a specific model of a **Piezoelectric Buzzer (Transducer)**, typically manufactured by companies like Hitpoint. It is widely used in electronics for providing acoustic feedback or alarms. Below is a detailed breakdown of its electronic specifications and characteristics. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Type** | Piezoelectric Transducer (External Drive) | | **Operating Voltage** | 1.0 - 30.0 Vp-p (Max) | | **Rated Voltage** | 3.0 - 5.0 Vp-p | | **Current Consumption** | $\leq$ 3mA at Rated Voltage | | **Sound Pressure Level (SPL)** | $\geq$ 80 dB (at 10cm / 4.0kHz) | | **Resonant Frequency** | 4,000 Hz ± 500 Hz | | **Operating Temperature** | -20°C to +70°C | | **Mounting Type** | Through-hole (PCB Mount) | --- ### 2. Electronic Components & Construction The P-213N-R is a **passive** piezo device, meaning it does not have internal oscillation circuitry. Its construction includes: * **Piezoelectric Ceramic Disc:** A thin layer of lead zirconate titanate (PZT) attached to a metal diaphragm (usually brass or stainless steel). When a voltage is applied, the "Inverse Piezoelectric Effect" causes the disc to deform. * **Plastic Housing (Noryl/PBT):** Designed as a Helmholtz resonator to amplify the sound waves generated by the ceramic disc. * **Terminals:** Two tin-plated brass pins for soldering onto a Printed Circuit Board (PCB). The "R" in the suffix often denotes compliance (RoHS) or a specific lead spacing/orientation. --- ### 3. Driving Circuit Requirements Unlike an active buzzer (which beeps when DC power is applied), the **P-213N-R requires an AC signal or a PWM (Pulse Width Modulation) signal** to produce sound. #### Typical Driving Methods: 1. **Transistor Switching:** A simple NPN transistor (like a 2N2222) can be used to switch the ground line at 4.0kHz. 2. **H-Bridge Drive:** For maximum volume, an H-bridge circuit can double the effective voltage across the piezo (e.g., from 5V to 10Vp-p). 3. **MCU Direct Drive:** If the current draw is low enough (typically < 3mA), it can sometimes be driven directly from a microcontroller I/O pin with a current-limiting resistor, though a transistor is safer. ```cpp // Example: Arduino code to drive the P-213N-R at its resonant frequency void setup() { pinMode(9, OUTPUT); // Connect Buzzer to Pin 9 } void loop() { tone(9, 4000); // Send a 4kHz signal delay(1000); // Wait 1 second noTone(9); // Stop sound delay(1000); } ``` --- ### 4. Comparison: Active vs. Passive (P-213N-R) | Feature | Active Buzzer | P-213N-R (Passive) | | :--- | :--- | :--- | | **Drive Signal** | DC (Fixed Voltage) | AC / Square Wave | | **Complexity** | Simple (Plug & Play) | Requires frequency generation | | **Flexibility** | Fixed Tone | Variable Pitch/Melody possible | | **Cost** | Slightly Higher | Lower |