Disclosed is a portable spot welder. The spot welder includes a control board; a battery connected to the control board; an analog-to-digital converter (ADC) detection module connected to the control board; a power metal oxide semiconductor (MOS) module connected to the battery; an optical-coupler isolation driving module connected to the power MOS module and the control board; a battery protection module connected to the battery and the control board; a power supply module connected to the battery protection module and the control board; and a soldering iron module connected to the battery protection module and provided with spot welding pen interfaces. The spot welder can be connected to an external spot welding pen for use or used as an emergency power bank. A safety coefficient is improved, risks of overheating, overcurrent and a short circuit of a portable spot welder body are reduced, and a size is reduced.

A power tool system includes a removable battery pack a first tool and a second tool. The first tool includes a first base housing that is selectively engageable with the removable battery pack and a first tool portion connected to the first base housing by a first connecting section. The second tool includes a second base housing that is selectively engageable with the removable battery pack and a second tool portion connected to the second base housing by a second connecting section. The second tool base housing houses a second controller that provides a proportional power delivery system for the second tool and second tool base housing also includes a second actuator for providing user control of the second tool.

A soldering tool includes an orientation sensor to interrupt power in a non-upright condition and a touch sensor to override the orientation sensor to allow a user to employ the tool in non-upright positions.