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USB Charger Doctor Inline Voltage Current Meter Tester - USB Power Diagnostic For Sale

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USB Charger Doctor Inline Voltage Current Meter Tester - USB Power Diagnostic

Price: US $6.89

**USB Charger Doctor: Current & Voltage Meter for Any USB Device**Instantly measure voltage and current with the USB Charger Doctor! This compact inline meter tests any USB power source, from wall chargers to power banks. Simply connect, and the 7-segment LED display alternates between showing voltage (3.5V-7.0V) and current (0-3A). Ideal for diagnosing charging issues or verifying USB output quality. **Key Features:**- **No Setup Required:** Just plug it in and read the results.- **Wide Compatibility:** Works with laptops, USB hubs, Arduino, and Raspberry Pi.- **Real-Time Diagnostics:** Perfect for testing charger outputs and cable quality.**Order Now** for fast free US shipping and ensure optimal charging for your USB devices!

Electronics for IoT, Prototyping & DIY

The USB Charger Doctor is an inline voltage and current meter that lets you instantly measure the output of any USB port or charger. Simply plug it between your USB power source and your device -- the built-in 7-segment LED display alternates between showing voltage and current readings. No batteries, no setup, no software required.

🔧 How It Works

Plug the male USB-A end into any USB power source -- a wall charger, laptop USB port, power bank, or USB hub.
Plug your USB device or cable into the female USB-A socket on the other end of the Charger Doctor.
Read the display -- the 4-digit LED display automatically alternates between showing the voltage (in volts) and the current draw (in amps).
Diagnose -- compare the readings to expected values. A healthy USB port should show approximately 5.0V. Current draw depends on the connected device.

⚡ Key Features

Instant Readings -- Plug in and immediately see voltage and current on the built-in LED display
Alternating Display -- Automatically cycles between voltage (V) and current (A) readings
Wide Measurement Range -- Reads voltage from 3.5V to 7.0V and current from 0 to 3A
High Resolution -- Voltage resolution of 10 mV (0.01V), current resolution of 1 mA (0.001A)
No Power Source Needed -- Powered directly from the USB connection being tested
Transparent Pass-Through -- All four USB lines (VCC, D+, D-, GND) pass through to the connected device
Compact Inline Design -- USB-A male plug on one end, USB-A female socket on the other
Transparent Blue Case -- See-through housing lets you view the internal PCB

📐 SpecificationsVoltage Measurement Range3.5V – 7.0VVoltage Resolution10 mV (0.01V)Current Measurement Range0 – 3ACurrent Resolution1 mA (0.001A)Current Sense Resistor0.05 ohm (50 milliohm) inline shuntDisplay4-digit 7-segment red LEDDisplay ModeAlternates between voltage and currentInput ConnectorUSB Type-A male plugOutput ConnectorUSB Type-A female socketData LinesD+ and D- pass through (transparent to data)Power SupplyPowered from USB bus -- no batteries requiredDimensionsApprox. 56 x 18 x 10 mm (2.2 x 0.71 x 0.39 inches) L x W x H 📊 Reading the Display

The display alternates between two readings every few seconds:

ScenarioExpected VoltageExpected CurrentStandard USB 2.0 port4.75V – 5.25VUp to 0.5AUSB 3.0 port4.75V – 5.25VUp to 0.9AUSB wall charger (1A)4.9V – 5.3VUp to 1.0AUSB wall charger (2.1A)4.9V – 5.3VUp to 2.1APhone charging (typical)~5.0V0.3A – 1.5ATablet charging (typical)~5.0V1.0A – 2.4A 📦 What's in the Box

1x USB Charger Doctor Inline Voltage and Current Meter

🔌 Compatible With

USB wall chargers and power adapters (any brand)
Laptop and desktop USB ports (USB 2.0 and 3.0)
USB power banks and portable battery packs
USB hubs (powered and unpowered)
Any device with a USB Type-A port
Arduino, Raspberry Pi, and other USB-powered development boards

🎯 Typical Applications

Verifying USB wall charger output voltage and current capacity
Diagnosing slow-charging phones and tablets
Testing laptop and desktop USB port output
Measuring USB power bank output and remaining capacity
Checking USB cable quality by measuring voltage drop under load
Monitoring current draw of USB-powered Arduino and Raspberry Pi projects
Comparing charging performance of different chargers and cables
Quality control testing of USB power supplies
Educational tool for learning about voltage, current, and power

💡 Tip: To test USB cable quality, measure the voltage at the Charger Doctor with no device connected, then connect a device and note the voltage drop. A good cable will show less than 0.2V drop under load. A larger drop indicates a low-quality or damaged cable. ⚠️ Important Notes

This device measures standard USB 5V power only. It is not designed for USB-C Power Delivery (PD) or Qualcomm Quick Charge voltages above 7V.
The maximum current rating is 3A. Do not use with devices that draw more than 3A.
The 0.05 ohm shunt resistor introduces a small voltage drop proportional to current draw. At 1A the drop is approximately 0.05V; at 3A it is approximately 0.15V.
The display alternates between voltage and current -- it does not show both simultaneously.
Data lines (D+ and D-) pass through transparently, so the Charger Doctor does not interfere with data transfer or device charging negotiation.
This is a measurement tool only -- it does not regulate, limit, or modify the USB power in any way.
Not suitable for measuring USB-C connections (different connector type).

🏪 About Envistia Mall

Envistia Mall is a US-based electronics retailer specializing in development boards, sensors, modules, and components for makers, engineers, and educators. We ship from the United States with fast handling times. Product documentation and technical support are available at our dedicated support site.

📦 Fast Free US Shipping | 🔄 Hassle-Free Returns | 📧 Responsive Customer Support

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