📋 Overview
The D3806 is a digitally controlled DC-DC power converter module that can both step up (boost) and step down (buck) voltage. It accepts an input voltage of 10–40V DC and provides an adjustable output from 0–38V DC at up to 6A. Whether your input voltage is higher, lower, or equal to your desired output, this module handles it all in one compact board.
The module operates in both Constant Voltage (CV) and Constant Current (CC) modes, making it ideal for powering projects, charging batteries, testing electronics, or building a benchtop power supply. A built-in four-digit LED display shows real-time output voltage, current, power (watts), and capacity (amp-hours), and three front-panel buttons give you full control over all settings.
With 10 memory presets for saving voltage/current combinations and three configurable special functions, the D3806 is a versatile tool for hobbyists, makers, and electronics professionals alike.
💡 Tip: This module works great as a simple benchtop power supply. Pair it with a 12V or 24V laptop-style power adapter as your input source, and you'll have an adjustable supply for most low-voltage projects.
⭐ Key Features
- Boost and Buck in One Module — Steps voltage up or down from a single input, no need for separate converters
- Wide Input Range — Accepts 10V to 40V DC input
- Adjustable Output — 0V to 38V DC output at up to 6A
- CC/CV Modes — Constant Voltage and Constant Current with LED indicators showing active mode
- Built-In Digital Display — Four-digit LED shows voltage, current, power (W), and capacity (Ah) in real time
- 10 Memory Presets — Save and recall up to 10 voltage/current parameter sets
- Three Special Functions — Auto-output on power-up, parameter save/recall, and auto-rotate display
- Simple Three-Button Interface — SET, OK, and ▲/▼ buttons for easy operation
- Fan Header — +12V fan connector for active cooling under heavy loads
- DC Power Jack — Convenient barrel jack input in addition to screw terminals
📊 Specifications
| Input Voltage | DC 10V – 40V |
| Maximum Input Current | 8A |
| Output Voltage | DC 0V – 38V (adjustable) |
| Output Current | 0A – 6A (adjustable) |
| Operating Mode | CC (Constant Current) / CV (Constant Voltage) |
| Display | 4-digit LED (voltage, current, power, capacity) |
| Memory Presets | 10 groups (M0–M9) |
| Input Connector | Screw terminals + DC barrel jack |
| Output Connector | Screw terminals |
| Fan Header | +12V DC, 2-pin |
| Operating Temperature | -40°C to +85°C |
| Board Dimensions | Approx. 100 × 80 × 35 mm (3.94 x 3.15 x 1.38 inches) L × W × H |
| Weight | Approx. 180g (6.4 ounces) |
⚠️ Important: Input voltage must be between 10V and 40V DC. Do not exceed 40V input or 8A input current. Never reverse the input polarity — this will damage the module. Always verify your connections before applying power.
📌 Module Layout
The D3806 module has the following connections and controls:
| #1 — +Vin | Positive DC input (screw terminal) |
| #2 — -Vin | Negative DC input (screw terminal) |
| #3 — DC Jack | DC barrel power socket (alternative input) |
| #4 — Fan Header | +12V fan interface (2-pin connector) |
| #5 — +Vout | Positive DC output (screw terminal) |
| #6 — -Vout | Negative DC output (screw terminal) |
| #7 — Display | 4-digit LED display and status indicators (OUT, CV, CC) |
| #8 — Buttons | Three operation buttons: SET, OK, ▲/▼ |
⚠️ Important: You can use either the screw terminals (#1 and #2) or the DC barrel jack (#3) for input power — do not use both at the same time. The screw terminals are recommended for higher current applications.
🔌 Wiring / Connections
Input Wiring
- Connect your DC power source positive (+) wire to the +Vin screw terminal (#1)
- Connect your DC power source negative (−) wire to the -Vin screw terminal (#2)
- Alternatively, plug a compatible DC barrel plug into the DC Jack (#3)
Output Wiring
- Connect your load's positive (+) wire to the +Vout screw terminal (#5)
- Connect your load's negative (−) wire to the -Vout screw terminal (#6)
Fan (Optional)
If you're running the module at higher power levels, connect a 12V DC cooling fan to the Fan Header (#4). This is especially recommended when operating near the maximum current rating for extended periods.
⚠️ Warning: Double-check polarity before applying power. Reversing the input polarity will damage the module permanently. There is no built-in reverse polarity protection.
🚀 Getting Started — Simple Mode
The D3806 ships in Simple Mode by default. This is the easiest way to get started and covers most use cases. Follow these steps:
Step 1: Apply Power
Connect your input power source (10V–40V DC) to the input terminals. The LED display will light up and show the default voltage setting (e.g., 00.00).
Step 2: Set Your Desired Output Voltage
- After power-on, the display shows the voltage value in the format 00.00 (two decimal places)
- Press the ▲ button to increase the voltage, or ▼ to decrease it
- A short press adjusts the value precisely (small increments); a long press adjusts quickly
Step 3: Set Your Desired Current Limit
- Press the SET button to switch the display to current mode — the format changes to 0.000 (three decimal places)
- Use the ▲ and ▼ buttons to set your desired current limit
- Press SET again to save the value — the display will briefly show a confirmation
💡 Tip: The voltage display uses two decimal places (e.g., 12.50 = 12.50V), while the current display uses three decimal places (e.g., 1.500 = 1.500A). This is how you can tell which parameter you're viewing at a glance.
Step 4: Enable the Output
Press the OK button to turn on the output. The OUT indicator LED will light up, and either the CV (Constant Voltage) or CC (Constant Current) indicator will illuminate depending on your load conditions.
Step 5: Adjust While Running
While the output is active:
- Voltage display showing: Press ▲/▼ to adjust output voltage in real time
- Current display showing: Press ▲/▼ to adjust the current limit in real time
- Short press OK: Cycle the display between voltage, current, power (W), and capacity (Ah)
- Long press OK (3 seconds): Enable auto-rotate display mode (cycles through all readings automatically). Press OK again to cancel auto-rotate
Step 6: Disable the Output
Press the SET button while the output is active to turn off the output.
🛠️ Understanding the Display
The 4-digit LED display shows different values depending on the current mode. Here's how to read each display format:
| 00.00 | Voltage — Range: 0.00V to 38.00V |
| 0.000 | Current — Range: 0.000A to 6.000A |
| P.123 | Power — 0.123W (decimal shifts with magnitude: P1.23 = 1.23W, P12.3 = 12.3W, P102 = 102W) |
| C.123 | Capacity — 0.123Ah (decimal shifts with magnitude: C1.23 = 1.23Ah, C12.3 = 12.3Ah, C123 = 123Ah) |
| --0- | Special Function 0 selection |
| --1- | Special Function 1 selection |
| --2- | Special Function 2 selection |
| --y- | Current special function is ON |
| --n- | Current special function is OFF |
| SA.-# | Save parameters to memory slot # (0–9) |
| Lo.-# | Load (recall) parameters from memory slot # (0–9) |
| Γ--n | Reset confirmation |
🔧 Special Functions (Full-Function Mode)
The D3806 has three special functions that are disabled by default. You can enable or disable each one independently.
How to Enable/Disable Special Functions
- Hold down the OK button, then power on the module (plug in the input power while holding OK)
- The display will cycle through --0-, --1-, --2-
- Release the OK button when the function number you want to toggle is displayed
- The display will show --y- (function is now ON) or --n- (function is now OFF)
Function 0 — Auto-Output on Power-Up
When enabled, the module automatically enables the output as soon as power is applied. This is useful for permanent installations where you want the module to start delivering power immediately without pressing any buttons.
Function 1 — Save/Recall Parameter Presets
When enabled, the SET button cycles through additional options beyond voltage and current: you can access the Save (SA.-#) and Load (Lo.-#) screens to store and recall parameter presets.
Example: Save 10V / 1.5A to Memory Slot 1
- Press SET to display voltage. Set it to 10.00V using ▲/▼. Press SET to save.
- Press SET to display current. Set it to 1.500A using ▲/▼. Press SET to save.
- Press SET until the display shows SA.-0. Press ▲ to change to SA.-1. Press OK to save the parameters to slot 1.
Example: Recall Parameters from Memory Slot 1
- Press SET until the display shows Lo.-0. Press ▲ to change to Lo.-1. Press OK to load the saved parameters from slot 1.
💡 Tip: The module has 10 memory slots (0–9). Each slot stores an independent voltage and current pair. This is great if you regularly switch between different voltage/current settings for different projects — just save each one to a slot and recall it with a few button presses.
Function 2 — Auto-Rotate Display
When enabled, the display automatically cycles between voltage, current, power, and capacity readings while the output is active. This gives you a hands-free overview of all output parameters.
🎯 Typical Applications
- DIY Benchtop Power Supply — Pair with a 12V or 24V adapter for an adjustable lab supply
- Battery Charging — Use CC/CV mode to charge lithium, lead-acid, or NiMH batteries
- LED Driver — Set constant current to safely drive high-power LEDs
- Solar Power Systems — Regulate solar panel output to a stable voltage
- Electronics Testing — Provide precise, adjustable voltage and current for testing circuits
- Voltage Conversion — Step up a 12V car battery to 24V, or step down 24V to 12V or 5V
- Portable Power Systems — Regulate battery packs for field equipment
💡 Tips and Best Practices
- Set voltage and current before enabling output. Always configure your desired values first, then press OK to enable the output. This prevents accidental overvoltage or overcurrent to your load.
- Use adequate input power. Your input power source must be capable of supplying enough current for your desired output. Remember, if you're boosting voltage, the input current will be higher than the output current.
- Add a cooling fan for heavy loads. The module includes a 12V fan header. If you're running at high power levels (especially above 50W) for extended periods, active cooling will improve reliability and longevity.
- Use short, thick wires. For high-current applications, use appropriately sized wire (14–16 AWG or thicker) and keep wire runs as short as possible to minimize voltage drop.
- Start with a low current limit. When connecting to a new or unknown load, set the current limit low and gradually increase it. The CC mode will protect your load from excessive current.
- Save your favorite settings. Enable Function 1 and use the 10 memory presets to store commonly used voltage/current combinations. This saves time when switching between projects.
⚠️ Important Notes and Limitations
- No reverse polarity protection. Connecting the input with reversed polarity will permanently damage the module.
- Input voltage range is strict. The input must be between 10V and 40V. Voltages below 10V may cause unstable operation; voltages above 40V may damage the module.
- Maximum input current is 8A. Even though the output can deliver up to 6A, the input side can draw up to 8A depending on the boost ratio. Make sure your power source and wiring can handle this.
- Power dissipation generates heat. At high power levels, the module will generate significant heat. Ensure adequate ventilation or use the fan header for active cooling.
- Output voltage cannot exceed input voltage significantly without derating. While the module can boost voltage, very large step-up ratios (e.g., 12V in to 38V out) will reduce the available output current. Plan your input voltage accordingly.
- Not isolated. The input and output share a common ground. This module does not provide galvanic isolation between input and output.
- Default memory slot is M0. If you don't specify a memory slot, the module saves to and loads from slot M0.
🏪 Where to Buy the D3806
This module is available from Envistia Mall.
Buy the D3806 DC-DC Boost Buck CC/CV Power Converter Module →
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📚 Additional Resources
- Manufacturer's Datasheet: D3806 Manufacturer's Datasheet (PDF)
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Video Review: Tech Talk: Ming He D3806 Boost Buck Digital PSU (YouTube)
This guide is provided by Envistia Mall for educational and technical reference purposes. The manufacturer and Envistia LLC (dba Envistia Mall) are not responsible for any damages or losses resulting from the use of this product. Always follow proper electrical safety practices when working with electronic components. Specifications are based on manufacturer data and are subject to change without notice.