Turns Counter Magnetic for iPhone

Purpose and primary use

Turns Counter Magnetic is an iPhone utility that helps you count turns while winding inductors. It reads the phone’s built-in magnetic field sensor to detect rotations of a magnet, letting you translate that motion into coil turns. The app can also track the handset’s own rotation (no external magnet required), which is useful when handling larger coils.

Practical capabilities

• Take a photo that overlays the measurement results for reference or documentation.
• Start a countdown timer to prepare or pace your winding process.
• Customize the audible alert pattern (for example, by repeating a character) to make notifications more noticeable.
• Receive a short signal each time the app registers an additional turn.
• Get notified when a preset target number of turns has been reached.
• Tune the sensitivity threshold so the app only reacts to meaningful changes in the magnetic field.
• Select which magnetometer axis the app should monitor to match your winding setup.

Calibration and setup

Before taking measurements, calibrate the magnetometer: position the phone where you will perform the winding, make sure there are no nearby magnets or strong ferrous objects, and press the “0” control at the top of the screen to zero the reading. Proper calibration helps ensure consistent and accurate counts.

Performance limits and precautions

The app supports rotation speeds up to about 1000 RPM (roughly 16 Hz) and reports rotation-speed measurements with an accuracy on the order of ±2% within that operating range. Avoid extremely high rotational speeds: a magnet can fly off and damage the device or cause injury if it detaches.

Alternative option

Recommended alternative: AppValley (free).

Quick summary

Turns Counter Magnetic is a straightforward tool for people who wind inductors, offering both magnet-based and phone-rotation counting modes, configurable sensitivity and alerts, and photo capture of results. Calibrate before use and keep rotational speeds within safe limits to protect yourself and your smartphone.