The term **79110** typically refers to a specific series of **Voltage Regulators**, specifically the **79xx series** of negative fixed-voltage regulators. The "79" indicates a negative output, while the "10" indicates a 10-volt output. --- ## 1. Technical Overview: 7910 / 79110 Voltage Regulator The 7910 is a monolithic integrated circuit designed as a fixed-voltage regulator for negative voltage applications. While the 78xx series handles positive voltages, the 79xx series is its complement. ### Key Specifications | Feature | Description | | :--- | :--- | | **Output Voltage** | -10V DC | | **Input Voltage (Max)** | -35V DC | | **Output Current** | Up to 1.5A (with proper heatsinking) | | **Package Type** | Commonly TO-220 | | **Protection** | Internal thermal overload & short-circuit protection | --- ## 2. Pin Configuration Unlike the 78xx (Positive) series, the pinout for the 79xx series is different. It is crucial to identify them correctly to avoid damaging the component. | Pin Number | Function | Description | | :--- | :--- | :--- | | **Pin 1** | **Ground (GND)** | Reference point (connected to 0V) | | **Pin 2** | **Input (IN)** | Negative unregulated voltage input | | **Pin 3** | **Output (OUT)** | Regulated -10V DC output | --- ## 3. Circuit Implementation To ensure stability and reduce noise, capacitors are required at both the input and output stages. ### Typical Wiring Diagram ```text (Unregulated -Vin) ----[ Pin 2: IN ]----[ Pin 3: OUT ]---- (Regulated -10V) | | [Pin 1: GND] | | | (0V) (C2: 1uF) | (C1: 2.2uF) ``` * **C1 (Input Capacitor):** Required if the regulator is far from the power supply filter. * **C2 (Output Capacitor):** Improves transient response and stability. --- ## 4. Common Applications 1. **Dual Power Supplies:** Used alongside a 7810 regulator to create a +/- 10V rail for Operational Amplifiers (Op-Amps). 2. **Audio Circuits:** Providing clean, negative rails for signal processing. 3. **Industrial Controls:** Negative bias voltage for sensors or displays. --- ## 5. Important Design Considerations * **Heat Dissipation:** The power dissipated is calculated as $P = (V_{in} - V_{out}) \times I_{out}$. If this value is high, a **heatsink** is mandatory. * **Common Ground:** The metal tab on a TO-220 79xx regulator is usually connected to the **Input** pin, not the Ground pin. This differs from the 78xx series where the tab is Ground. Be careful when mounting to a shared chassis.