maker tools - hardware testing · 2026
USBSafe
Active USB port protection for makers who build without limits
USBSafe is an active protector that sits between your computer and any untested hardware, shielding your device from overcurrent, short circuits and voltage spikes, with real-time LED status indicators
This is why we built the USBSafe
The maker's shield for USB ports
You’ve spent hours on a circuit. Maybe days. And now it’s time to connect it to your computer and see if it works.
That moment, before you plug in, is exactly what USBSafe was made for.
USBSafe is an inline USB port protector that sits between your machine and whatever you’re testing. It monitors the connection in real time and cuts it the instant something goes wrong: too much current, a voltage spike, a short, a discharge on the data lines. Your computer never feels it.
Built around a configurable current-limiting IC, a TVS clamping diode, and dedicated ESD protection on both USB data lines, USBSafe isn’t a passive adapter. It’s an active circuit that watches your connection so you don’t have to.
Built by makers for makers
Who is this for
For hardware makers testing self-built circuits. For embedded developers connecting boards that haven’t been proven yet. For electronics students and hobbyists who build with their own hands and test on their own machines.
If you’ve ever hesitated before plugging something in, USBSafe removes that hesitation — and replaces it with a data point.
Why do you need it
A damaged USB controller often means a damaged motherboard. It’s not a port you can swap out — it’s a repair that costs significantly more than the project you were testing.
USBSafe costs a fraction of that. And it sits on your bench ready for the next test, and the one after that.
The dual LED indicators — blue for normal, red for fault — give you real-time feedback on what’s happening at the connection. The translucent lid version keeps those LEDs visible wherever you place it.
Specifications
How does it work?
Three independent protection layers working at the same time
Current limiting
Before you connect anything, you choose your current threshold with the onboard switch. LO mode limits to 100 mA, the right choice for unknown or sensitive hardware. HI mode allows up to 500 mA for boards with higher power requirements. The moment current exceeds your chosen limit, the circuit trips and disconnects.
Voltage spike clamping
A transient voltage suppressor on the power line catches spikes above 5V in nanoseconds. Inductive loads, back-EMF, faulty regulators — absorbed before they travel any further.
ESD protection on data lines
Most protection solutions only cover the power lines. USBSafe also protects D+ and D−, the USB data lines that carry signals directly to your host controller. Electrostatic discharge on those lines causes the kind of damage that doesn’t show up immediately — it accumulates, quietly, until something fails.
Backup thermal fuse
A hardware-level last resort. If sustained current heats the fuse past its trip point, it opens the circuit completely. No action needed — it resets on its own once it cools down.
LED logic
The dual Schmitt trigger inverter drives the status LEDs with clean switching logic, avoiding indeterminate states. Blue means the connection is live and within parameters. Red means a fault was detected and the circuit has acted on it.
Technical specs
| Interfaces | USB Type-A male (host) / USB Type-A female (device) |
| Protection modes | HI: 500 mA · LO: 100 mA — user-selectable via onboard switch |
| Current limiting IC | Rohm BD2243G-GTR |
| Overvoltage protection | TVS diode SMBJ5.0A — clamp at 5V |
| ESD protection (data lines) | ST TPUSBLC6-2SC6 — covers D+ and D− |
| Backup thermal fuse | Littelfuse 500 mA — auto-resetting |
| Status indicators | 2× Blue LED (normal) · 2× Red LED (fault) |
| LED logic | TI SN74LVC2G14 dual Schmitt trigger inverter |
| Enclosure | Industrial 3D printed resin — opaque black / translucent lid |
| Designed by | blackdevice |
| Manufactured by | Elecrow |