The **ALR-413-R** is a specific electronic component typically categorized as a **Photoelectric Control (Photocontrol)** or a **NEMA Plug-in Light Sensor**. These devices are primarily used in outdoor lighting systems (like streetlights or security lights) to automatically turn the fixture ON at dusk and OFF at dawn. Below is a breakdown of its electronic characteristics and specifications. --- ### 1. Technical Specifications The ALR-413-R is designed to handle standard utility voltages and high-intensity discharge (HID) or LED loads. | Feature | Specification | | :--- | :--- | | **Input Voltage** | 105 - 130 VAC | | **Frequency** | 50/60 Hz | | **Load Rating (Tungsten)** | 1000 Watts | | **Load Rating (Ballast)** | 1800 VA | | **Turn-On Level** | 1.5 Foot-candles (fc) | | **Turn-OFF/ON Ratio** | 4:1 | | **Housing Material** | Polypropylene (UV Stabilized) | | **Connection Type** | 3-Prong NEMA Twist-lock | --- ### 2. Internal Electronic Components The device functions through a series of integrated components that translate light intensity into electrical switching. #### A. The Sensor (Cadmium Sulfide Cell) The "eye" of the unit is usually a **CdS Photocell**. - **Operation:** Its resistance decreases when exposed to light and increases in the dark. - **Role:** It acts as the primary trigger for the internal circuit. #### B. Thermal Relay or Electromagnetic Relay Depending on the specific revision of the ALR series: - **Thermal Switch:** Uses a bimetallic strip heated by a resistor. When the photocell allows current to flow (at night), the heater cools or activates, causing the strip to bend and close the load contacts. - **Electromagnetic:** Modern versions may use a small electromagnetic coil to snap the contacts shut, providing a "click" sound and instant switching. #### C. Surge Protection (MOV) Most units in the ALR-413 series include a **Metal Oxide Varistor (MOV)**. - **Purpose:** Protects the internal circuitry and the connected light fixture from voltage spikes caused by lightning or grid fluctuations. --- ### 3. Connection Interface The unit uses a standard **NEMA 3-pole twist-lock plug**. The pinout follows industry standards: 1. **Line (Black):** Connects to the incoming AC power. 2. **Neutral (White):** Connects to the common AC neutral. 3. **Load (Red):** Connects to the light fixture itself. --- ### 4. Key Features * **Time Delay:** The internal circuitry includes a slight delay (usually 30-60 seconds) to prevent the light from flashing off due to temporary light sources like car headlights or lightning. * **Fail-On Mode:** Most ALR series controllers are designed to fail in the "ON" position. If the sensor or internal circuit breaks, the light stays on during the day, signaling that maintenance is required.