FlyFocus develops detachable tethered UAV allowing mission critical surveillance

Using Vicor DCM DC-DC converters for heavier payloads or longer flight time

FlyFocus’s new CableGuard is a detachable tethered UAV for civilian and law enforcement markets. In tethered mode, it hovers at altitudes to 70 metres for extended times; however, a remote command detaches the tether cable, allowing the UAV to freely fly and track a suspicious object for up to 30 minutes.

At 5kW, the UAV is rated as the most powerful tethered type available on the market today. This capability is in part facilitated by FlyFocus’s use of Vicor isolated, regulated DCM DC-DC converters within the power delivery network from the tether cable to the UAV’s motors and electronics.

Detachable tethered UAV challenges and Vicor’s contribution

In tethered mode, the UAV’s electric motors and onboard electronics are powered via the tether cable, which delivers 400VDC from the ground station; this lets it perform surveillance virtually indefinitely, with only occasional landings for maintenance inspections. When the UAV untethers for free flight, onboard batteries seamlessly take over the vehicle’s power supply, allowing up to 30 minutes’ flight with a single daylight camera payload, and 20 minutes with a dual thermal plus daylight camera setup. These untethered flight times give FlyFocus a competitive edge for their surveillance applications.

FlyFocus uses the high 5kW of power available through the tether cable to enhance both the UAV’s performance and its functionality. With eight motors, it can be safely landed even with two motors disabled. The two cameras provided are a full HD type with 10x optical zoom and 4x digital zoom, and a night vision IR 640p camera with 4x digital zoom.

The power capacity allows FlyFocus to use better-quality cameras such as heavy cooled thermal types, or cameras with enhanced zoom. Additional payload modules also become possible.

Vicor isolated, regulated DC-DC converters are designed into the power delivery network from the tether cable to the UAV’s motors and electronics. They can buck the tether cable’s 400VDC down to the UAV’s operating voltages; accommodating this high voltage reduces cable current and I2R losses. Accordingly, a much smaller, lighter cable can be used – always advantageous in such airborne applications. 

Additionally, the DCMs’ power density far exceeds that of any other FlyFocus supplier. Together with their efficient operation, this allows eight 600W modules to be packed into a limited-size pod under the UAV, with just two heatsinks/fans.