Method and apparatus for protecting circuitry accessible through metallic contacts from static discharge damage

摘要

Electro-static discharge protection for sensitive circuitry in devices, which have exposed metallic contacts for accessing such circuitry, is achieved by providing switching apparatus in these devices. The switching apparatus isolates the sensitive circuitry from static electricity which may be impressed upon the exposed metallic contacts. In operation, when a first device is placed in engagement with a second device for transferring data, charging a battery or the like, the switching apparatus relies on the weight exerted by the first device on the second device for establishing a conducting path between the contacts and the sensitive circuitry in each device. This conducting path is interrupted when the first device is removed from the second device thereby providing isolation for the sensitive circuitry from any static electricity which may be impressed upon the exposed metallic contacts. The switching apparatus also is configurable for establishing a conducting path from the contacts on each device to ground potential whenever the first device is removed from the second device. The ground potential conducting path provides additional protection for the sensitive circuitry against electro-static discharge damage.