Cordless Electric Screwdriver

Overview

A cordless electric screwdriver is a small low-torque driver for repetitive fastening, assembling flat-pack furniture, fitting cabinet hardware, electronics work, where a full drill/driver is heavier than the job needs. It runs slowly and stops at a set torque so screws seat consistently without stripping the head or splitting the material. The handle usually pivots between an inline pen grip for access and a pistol grip for more push, and the cell charges in place from a USB port rather than on a separate dock.

The tool is built around the DC Motor, a small permanent-magnet DC motor running off the integrated Battery Cell Pack. Pressing the trigger feeds the Control Board board, which drives the motor through an H-bridge and reads the Forward/Reverse Switch to set direction. Power reaches the work through the Planetary Gearbox and the Torque Clutch, then out to the Bit Holder, which takes standard 1/4 in hex bits and holds them magnetically.

How it works

The motor spins fast but weakly, so the Planetary Gearbox trades that speed for torque. Two planetary stages, each a sun gear driving three planets inside a fixed ring, step the output down through their Planet Carrier plates to a slow, strong Output Spindle. Without reduction the motor could not seat a screw; with it, the small tool drives confidently.

Torque is limited by the Torque Clutch. The drive passes through spring-loaded Detent Ball Set held in pockets by a Coil Spring preloaded through the Clutch Collar. While resistance is low the balls stay seated and torque passes straight through; once the screw seats and torque climbs past the dialled limit, the balls ride up out of their pockets, the clutch ratchets, and driving stops, so every screw is set to the same depth. The Control Board also manages charging from the Charge Port and protects the cell through the pack's protection board. A drive-end Work Light lights the fastener, and the Housing & Grip carries the ratcheting pivot that swings the Soft Grip between inline and pistol positions.