ToolkitRC WM150 watt meter 1-50V/150A

ToolkitRC WM150 is a digital watt meter for measuring voltage, current and power in the power circuits of RC models and FPV drones. It connects between the power source (battery) and the load, showing the actual consumption of the power system, ESC or the entire aircraft. It operates in the 1-50V range and measures current up to 150A with 10mA accuracy. It can also generate a PWM signal to control an ESC or servo, making it suitable for bench testing motors and propellers without a transmitter and receiver.

There are four ports on the rear: SOURCE input for the power source, LOAD output for the load, a signal port and USB. It is powered directly from the measured source. When the input voltage is below 6V, it additionally requires USB power (5V/1A), otherwise it will not start or will trigger a low-voltage alarm. With USB power, it can also measure low-voltage circuits, such as those with a 1S battery.

Values are displayed on a colour 2,4" TFT display with 320x240 resolution. On the left is an analogue current gauge, in the centre is a bar graph of power in watts, and on the right are numerical readings: input voltage, consumed capacity, measurement time in seconds and output PWM signal parameters. Capacity is accumulated continuously and the unit switches automatically – up to 1Ah in mAh, above that in Ah. The lower part of the display shows the current waveform at the output over time, making current spikes clearly visible, for example when rapidly increasing throttle.

The output PWM signal has a fixed 20ms (50Hz) period and a 1000-2000µs pulse width with 1µs accuracy. The pulse width is set using the rotary knob on the front, and pressing the knob locks the value. The knob therefore acts as a throttle control: connect the ESC to the signal port, connect the watt meter to the power supply, and the motor current draw and power with a specific propeller can be monitored while smoothly increasing throttle. For safety reasons, the watt meter checks the knob position after power-on. If the knob is not at minimum, it displays a warning and will only operate after turning the knob to minimum.

The firmware is updated via USB: after connecting to a computer, the watt meter appears as a USB flash drive named Toolkit, and you simply copy the update file from the manufacturer's website onto it. The watt meter measures 80x54x23 mm and weighs 120g.

Important warning: Observe correct polarity when connecting the power source. Maximum input voltage is 50V and maximum current is 150A. The watt meter must not be used in heat, humidity, or flammable or explosive environments, and must not be left operating unattended. We recommend disconnecting the power source after measurement.