The **MA28TBD-R** is a specialized electronic component, typically categorized as a **High-Performance Piezoelectric Transducer (Buzzer)**. It is widely used in industrial and commercial applications where high reliability and specific acoustic output are required. Below is a detailed breakdown of its electronic characteristics and specifications. --- ### 1. General Specifications The "MA" series generally refers to products manufactured by brands like **Mallory Sonalert Products**. These components are designed to convert electrical energy into mechanical vibrations (sound). | Feature | Specification (Typical) | | :--- | :--- | | **Type** | Piezoelectric Audio Indicator | | **Operating Voltage** | 20 - 28 VDC | | **Current Consumption** | < 25 mA (at rated voltage) | | **Sound Level (SPL)** | 85 - 95 dB @ 2ft | | **Frequency** | 2900 ± 500 Hz | | **Tone Type** | Continuous / Constant | | **Mounting Type** | Panel Mount | --- ### 2. Key Electronic Characteristics #### A. Piezoelectric Element Unlike electromagnetic buzzers that use a coil and a magnet, the MA28TBD-R utilizes a **piezoelectric ceramic disc**. - **Advantage:** Low power consumption and minimal electromagnetic interference (EMI). - **Mechanism:** When voltage is applied, the ceramic material deforms physically, creating pressure waves in the air. #### B. Driving Circuitry The "TBD" designation often indicates internal circuitry that allows the device to operate directly from a DC power source. - **Internal Oscillator:** It includes an integrated circuit that converts the DC input into the specific AC frequency required to drive the piezo element. - **Polarity Protection:** Most models include a diode to protect the internal circuit against reverse polarity. #### C. Environmental Durability The "-R" suffix usually denotes **RoHS Compliance**, meaning the part is manufactured without hazardous substances like lead or mercury. It is also built to withstand: - **Operating Temperature:** -30°C to +65°C. - **Housing Material:** Noryl (UL94V-0) or similar flame-retardant plastic. --- ### 3. Connection and Integration The component usually features screw terminals or quick-connect blades for easy integration into industrial control panels. ```python # Typical Electrical Interface Power_Source = "24V DC" Connection_Type = "Screw Terminals" Wiring = { "Positive (+)": "Anode (Red or marked +)", "Negative (-)": "Cathode (Black or marked -)" } ``` --- ### 4. Common Applications * **Industrial Control Panels:** Status indicators for machinery. * **Medical Equipment:** Alarms for patient monitors. * **Marine Electronics:** High-decibel signaling in moisture-prone environments. * **Security Systems:** Audible alerts for breach detection.