The **FRS-03-R** is a specific type of **Flame Sensor (Flame Recognition Sensor)** designed primarily for industrial and domestic heating systems, such as boilers or furnaces. Its primary role is to detect the presence of a flame via ultraviolet (UV) or infrared (IR) sensing to ensure safety. --- ## 1. Core Electronic Specifications The FRS-03-R serves as the "eye" of the combustion system. Below are the typical technical parameters associated with this component: | Feature | Specification (Typical) | | :--- | :--- | | **Input Voltage** | 200V - 240V AC (50/60Hz) | | **Detection Method** | Flame Rectification / UV Sensing | | **Response Time** | < 1.0 Second | | **Output Type** | Relay Contact or Signal to Controller | | **Operating Temp** | -20°C to +60°C | --- ## 2. Key Internal Electronic Sections The FRS-03-R consists of three main stages that process the physical flame into an electronic signal: ### A. Sensing Element * **Photoelectric Tube:** In UV models, a gas-filled tube reacts to ultraviolet light (185–260 nm) emitted by the flame. * **Ionization Probe:** In some variations, it uses the "Flame Rectification" principle, where the flame acts as a diode to conduct electricity in one direction. ### B. Signal Conditioning Circuit * **Amplifier:** The raw signal from a flame is extremely weak (microamps). The internal circuitry uses an Operational Amplifier (Op-Amp) to boost this signal. * **Filter:** A band-pass filter is used to ensure the sensor does not react to ambient light or red-hot refractory bricks, focusing only on the flicker or spectrum of the flame. ### C. Logic & Output (The "R" Suffix) * **Electromagnetic Relay:** The "R" in the model name usually denotes **Relay Output**. * **Switching Mechanism:** When a flame is detected, the internal logic energizes a relay, closing a set of dry contacts. This informs the Main Control Board (BMS) that it is safe to continue pumping fuel. --- ## 3. Wiring Configuration Most FRS-03-R modules utilize a standard terminal block for integration: ```markdown Terminal 1: Line (AC L) Terminal 2: Neutral (AC N) Terminal 3: Common (Relay) Terminal 4: NO (Normally Open - Signal for Flame ON) Terminal 5: NC (Normally Closed - Signal for Flame OFF) Terminal 6: Flame Sensor Probe Input ``` --- ## 4. Operational Safety Features 1. **Fail-Safe Design:** If the internal electronic components fail, the relay is designed to drop out (Open), cutting off the fuel supply immediately. 2. **Self-Check:** Modern FRS units perform a "dark start" check to ensure the sensor isn't stuck in a "flame detected" state before the ignition sequence begins.