Abstract: Portable wireless telephone handset with a flap movable upon a housing. In a first position the flap is close to a speaker to enable the flap to be disposed near to a user's ear for the user to receive personal low volume sound from the speaker. In a second position, the flap is further from the speaker to detract from use of the speaker near to the user's ear. In the second position of the flap, the speaker operates in loudspeaker mode. A switch is provided to change the speaker between loudspeaker and low volume sound mode, the switch operation being dependent upon flap position.

Abstract: Electronic unit of printed circuit board with electronic components on one side and its other side in heat conducting contact with a heat sink enables the electronic components to be sealed from ambient atmosphere and thus unpackaged chips may be used. The units are mountable in a support frame with air cooling passages of the heat sinks extending vertically for convected cooling air. In each unit, a resistor network may extend into a cavity formed in a heat exchange rib and an electronic chip, perhaps unpackaged in the sealed environment, may be in heat conductive relationship with the heat sink.

Abstract: Electronic module of printed circuit board with electronic components on one side and its other side in heat conducting contact with a heat sink enables the electronic components to be sealed from ambient atmosphere and thus unpackaged chips may be used. The modules are mountable in a support frame with air cooling passages of the heat sinks extending vertically for convected cooling air. In each module, a resistor network may extend into a cavity formed in a heat exchange rib and an electronic chip, perhaps unpackaged in the sealed environment, may be in heat conductive relationship with the heat sink.