The metal is placed over a female dimpling die, and a male die is driven into it. The dies press the edges of the hole down so the head of the countersunk rivet or screw will be flush with surface of the metal.
diode (electrical component). A two-element electrical device. A diode contains an anode and a cathode and acts as an electron check valve. Electrons can pass from the cathode to the anode, but they cannot pass from the anode to the cathode.
A diode may be either a vacuum tube or a semiconductor device.
dioxide. A chemical compound which contains two atoms of oxygen. Carbon dioxide contains one atom of carbon and two atoms of oxygen (CO2).
DIP (integrated circuit packaging). The abbreviation for dual in-line package. Different types of integrated circuits and switches are mounted in DIPs, which are standardized with regard to size, pin spacing, and the distance between the two rows of pins.
dip (magnetic compass characteristic). The angle formed between a compass magnet aligned with the earth’s magnetic field and the horizontal plane.
Dip is caused by the vertical component of the earth’s magnetic field, and to correct for dip, a weight is often put on one end of the magnet to keep it horizontal. This weight is the cause of two errors found in aircraft magnetic compasses: acceleration error and northerly turning error. See acceleration error and northerly turning error.
dipcoating (insulation application). A method of electrically insulating the handles of certain tools, such as pliers, that are used in electrical work. The handles are dipped into a liquid plastic resin. The resin that sticks to the handle hardens and forms a comfortable, attractive, nonconductive grip.
diplexer (aircraft radio component). A coupling system used with an aircraft radio antenna. A diplexer allows two different transmitters to use the same antenna.
diplex operation (communications operation). A method of communicating which allows transmission and reception of two signals at the same time. Diplex operation uses a single antenna or a single carrier.
dipole antenna (radio antenna). A straight-wire, half-wavelength, center-fed radio antenna. The length of each of the two poles of the antenna is approximately one quarter of the wavelength of the frequency for which the antenna is designed.
dip soldering. The method of soldering component leads to a printed circuit board. The ends of the component leads pass through holes in the printed circuit board and stick out through the bottom. The board is floated on the top of a bath of molten solder, and the solder joins the component leads to the printed conductors.
dipstick. A gage, made in the form of a thin metal rod, used to measure the level of a liquid in a reservoir. The dipstick is pushed into the reservoir until it contacts a built-in stop; then it is removed and visually inspected. The level of the liquid in the reservoir is indicated by the amount of the dipstick wet by the liquid.
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