The **AH-24-R** typically refers to a specific model of an **Audible/Visible (A/V) notification appliance**, commonly a wall-mounted fire alarm horn strobe manufactured by companies like Potter Electric Signal or similar fire safety brands. Below is a breakdown of its electronic components, specifications, and functional design. ### 1. Technical Specifications The device is designed to operate within standard fire alarm control panel (FACP) parameters. | Feature | Specification | | :--- | :--- | | **Input Voltage** | 24V DC (Standard) or FWR (Full Wave Rectified) | | **Operating Range** | 16V to 33V DC | | **Strobe Intensity** | Fixed 15/75 Candela (typically) | | **Sound Output** | 82–100+ dBA depending on setting | | **Mounting** | Wall Mount | | **Color** | Red (indicated by the "-R" suffix) | --- ### 2. Core Electronic Components The AH-24-R consists of several integrated circuits and hardware components to manage power and signaling: #### A. The Xenon Flashtube (or LED) * **Function:** The "Strobe" portion. * **Electronics:** It uses a high-voltage trigger transformer and a storage capacitor. The circuitry converts the 24V DC input into a high-voltage pulse to ionize gas in the tube, creating a bright flash. #### B. Piezoelectric Transducer / Horn * **Function:** The "Audible" portion. * **Electronics:** A ceramic piezoelectric element vibrates when an oscillating electrical signal is applied. This model usually features a "Temporal 3" pattern generator (three pulses followed by a pause) required by modern life safety codes. #### C. Voltage Regulator & Protection * **Polarity Protection:** Includes a diode bridge to prevent damage if the wires are connected backward and to allow for supervision (reverse polarity monitoring) by the fire panel. * **In-rush Current Limiter:** Ensures that when the system starts, it doesn't cause a massive current spike that could trip the panel’s fuses. #### D. Synchronizing Circuitry * **Function:** Ensures multiple strobes in a room flash at the exact same time to prevent photosensitive epilepsy triggers. * **Logic:** It contains a logic chip that listens for a "sync pulse" from a synchronization module or a compatible FACP. --- ### 3. Connection Diagram Logic The device uses a standard terminal block for field wiring. ```mermaid graph LR A[FACP 24V Source] --> B[Terminal +] C[FACP Return] --> D[Terminal -] B --> E[Internal Strobe Circuit] B --> F[Internal Horn Circuit] D --> E D --> F ``` ### 4. Selection Switches (Jumper/DIP) Most AH-24-R units feature internal jumpers or switches that allow technicians to: 1. **Select Volume:** High or Low decibel output. 2. **Select Tone:** Continuous tone or Temporal 3 (ANSI S3.41) pattern. ---