# Beginner's Guide to the Lonely Binary AMS1117 Kit
## Introduction to the Kit
The **Lonely Binary AMS1117 Kit** is a handy, affordable toolkit for electronics hobbyists, makers, and beginners building projects with microcontrollers like Arduino, ESP32, or Raspberry Pi. Lonely Binary, an Australian-based online electronics supplier, specializes in high-quality, user-friendly components with fun, whimsical product descriptions that make learning electronics enjoyable. This kit focuses on the AMS1117 low dropout (LDO) voltage regulator, providing stable power for sensitive circuits.
The Lonely Binary AMS1117 Kit includes **18 pieces of AMS1117 3.3V fixed modules** (each with a built-in LED) and **6 pieces of AMS1117-ADJ adjustable modules** (without LED).
## What's in the Kit?
- **18 x AMS1117 3.3V Fixed Modules**: These compact boards use the AMS1117-3.3 chip to step down higher voltages (e.g., 5V from USB) to a steady 3.3V output. Each includes a **red power LED** that lights up when input power is applied, making it easy to confirm the module is working. Rated for up to 800mA, with built-in short-circuit and thermal protection.
- **6 x AMS1117-ADJ Adjustable Modules**: Similar size, but using the AMS1117-ADJ chip for customizable output (1.25V–12V). **No LED included**, as adjustable voltages could exceed safe levels (e.g., >5V) and risk burning out the indicator. Features a **multi-turn potentiometer (pot) on the back** for precise tuning.
- **Accessories**: Typically includes headers for breadboard compatibility, though not always pins pre-soldered. All modules have screw terminals or pin headers for easy input/output connections.
This mix gives you plenty of fixed 3.3V regulators for common MCU needs, plus adjustable ones for flexible experiments.
## Key Features and Specifications
The AMS1117 chip powers all modules—it's a reliable 1A LDO with low dropout (~1.1V at full load), meaning it works well even when input voltage is close to output. Here's a quick spec table:
| Feature | 3.3V Fixed Module | ADJ Module |
|---------|-------------------|------------|
| **Input Voltage** | 4.5V–15V | 4.5V–15V |
| **Output Voltage** | Fixed 3.3V | Adjustable 1.25V–12V |
| **Max Current** | 800mA (1A peak) | 800mA (1A peak) |
| **Dropout Voltage** | ~1.1V @ 800mA | ~1.1V @ 800mA |
| **Quiescent Current** | ~5–10mA | ~5–10mA |
| **Protections** | Thermal shutdown, overcurrent | Thermal shutdown, overcurrent |
| **LED Indicator** | Yes (red, input power) | No (to avoid high-voltage damage) |
| **Adjustment** | None | Multi-turn pot (back side) |
| **Size/Package** | ~20x10mm, SOT-223 | ~20x10mm, SOT-223 |
Efficiency is ~60–80% (heat = (Vin - Vout) × Iout), so use heatsinks for high loads. Modules include stability capacitors (10–22µF in/out).
## How to Use the Kit
### Setting Up the 3.3V Fixed Modules
1. **Connect Input**: Wire 5V–9V (e.g., USB or battery) to the IN+ and IN- terminals. The red LED glows to show power-on.
2. **Output**: Take 3.3V from OUT+ and GND. Powers ESP32s, sensors, or LEDs directly.
3. **Example**: On a breadboard, connect to an Arduino's 3.3V rail for low-voltage peripherals. Max load: 500mA safe for cooling.
### Setting Up the AMS1117-ADJ Modules
1. **Connect Input**: Same as fixed—5V–15V to IN+/IN-.
2. **Adjust Output**: Use a small screwdriver on the **back pot**. Start with input at 5V.
- Turn counterclockwise (CCW) 10–20 full turns to reach the minimum (~1.25V reference).
- Then, turn clockwise (CW) slowly to increase voltage. Measure with a multimeter on OUT+/GND.
3. **Output**: Custom Vout for unique needs, like 4.5V for certain motors.
4. **Example**: Power a 9V project from 12V input—set to 9V for stable supply without wasting too much heat.
## Why the Pot Takes 10–20 Turns to Start Changing Voltage
The potentiometer on the AMS1117-ADJ module is a **multi-turn trimmer pot** (often 10–15 turns total), designed for precision rather than quick tweaks. Here's why you might need 10–20 turns one direction before noticing a voltage change:
- **How It Works**: The pot acts as R2 in the AMS1117's voltage divider circuit. The chip maintains a fixed 1.25V reference between OUT and ADJ pins. Output voltage formula: Vout = 1.25V × (1 + R2/R1), where R1 is a fixed ~120Ω resistor on the board, and the pot (R2) is ~1kΩ–10kΩ total resistance.
- **Starting at One End**: If the pot is fully turned to the **maximum resistance end** (e.g., all CCW or CW, depending on wiring), R2 is at its highest value, setting Vout to its maximum (~13V). Turning the opposite way slowly reduces R2, but:
- **Mechanical Slack/Play**: Multi-turn pots have internal gearing (like a screw thread) for fine control. At the "end stop," there's often 5–10° of free play before the wiper (contact) actually moves along the resistive element. This feels like "empty" turns.
- **Full Range Coverage**: To sweep from max Vout (~12V) to min (~1.25V), you need the full 10–15 turns. If it's at one extreme, you'll burn through half the range (5–7 turns) with no noticeable change until you hit the active zone.
- **Suddenly Notices Change**: Once past the slack and into the resistive track, resistance drops quickly per turn, causing a sharp voltage shift (e.g., from 12V to 10V in one turn). This "sudden" feel is normal—it's precise adjustment kicking in.
- **Fix/Tip**: Always turn ~15 turns CCW first to hit the minimum (safest start), then CW to dial up. Avoid forcing past stops to prevent damage. If it's a cheap pot, slight wear can add extra play.
This design ensures accuracy (0.1V steps per partial turn) for calibration, unlike single-turn pots that jump wildly.
## Applications and Quick Tips
- **Projects**: Use 3.3V modules for ESP8266 WiFi nodes or sensor arrays. ADJ for variable LED drivers or battery testers.
- **Heat Management**: Modules get warm (e.g., 5V to 3.3V at 500mA = ~0.85W heat). Add a small heatsink if >300mA.
- **Safety**: Input <15V max. Test unloaded first. No reverse polarity—use diodes if needed.
- **Alternatives**: For efficiency, pair with Lonely Binary's buck converters; for more kits, check their ESP32 sets.
The Lonely Binary AMS1117 Kit is a beginner's dream—simple, robust, and fun. Grab one from lonelybinary.com or Amazon, and power up your next project. Questions? Their support is top-notch!
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