Anti-peak energy absorbing circuit for a power tool
Patent Information
- Authority / Receiving Office
- CN ยท China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHUHAI LINAI TECHNOLOGY CO LTD
- Filing Date
- 2025-07-15
- Publication Date
- 2026-06-09
AI Technical Summary
The freewheeling diodes in existing power tools are prone to damage under overload or stall conditions, leading to damage to the control circuit board. Furthermore, existing solutions cannot effectively absorb instantaneous currents in the tens of amperes and back electromotive forces lasting for hundreds of milliseconds, resulting in increased size or cost of power tools.
A reverse peak energy absorption circuit is composed of a nonpolar capacitor and/or diode, a controllable power switch, and a controllable freewheeling device (such as a MOSFET). By replacing the traditional diode with a MOSFET with low on-resistance, a low-power freewheeling loop is formed to absorb the peak current of the motor's back electromotive force and, when necessary, recharge the back electromotive force energy back to the drive power supply.
It achieves effective absorption of the back electromotive force of the motor while miniaturizing and reducing costs, thereby reducing the heat dissipation requirements of the control circuit board and improving the reliability and lifespan of the power tool.
Smart Images

Figure CN224342921U_ABST