| P |
|
|
|
| Parallel Circuit |
|
A circuit in which the identical voltage is presented to all
components, with current dividing among the components according
to the resistances or the impedances of the components. |
|
| Permittivity Relative |
|
Synonym term for relative dielectric constant.εr. |
|
| Phase |
|
An angular relationship between waves. |
|
| Phase shift |
|
Chang in phase of a voltage or current after passing through
a circuit or cable. |
|
| Pico |
|
One-trillionth (10-12) |
|
| Picofarad |
|
10-9 farad. Abbreviation pF or mmF. |
|
| Pin Contact |
|
A male type contact, usually designed to mate with a socket
or female contact.
It is normally connected to the dead side of a circuit. |
|
| Plastic |
|
High polymeric substances, including both natural and synthetic
products that are capable of flowing under heat and pressure,
called thermoplastics. Unlike rubber and other thermoset compounds,
plastics can be remelted and reused. |
|
| Plated through-hole |
|
A hole through a printed circuit board that has been electroplated
and which a lead is placed and soldered for electrical and mechanical
connection. |
|
| Polyethylene |
|
A thermoplastic material having excellent electrical properties. |
|
| Polymer |
|
A substance made of many repeating chemical units or molecules.
The term polymer is often used in place of plastic, rubber,
or elastomer. |
|
| Polyolefin |
|
Any of the polymers and copolymers of the ethylene family
of hydrocarbons,
such as polyethylene and polypropylene. |
|
| Polypropylene |
|
A thermoplastic similar to polyethylene but stiffer and having
a higher softening point (temperature). |
|
| Polyurethane |
|
Broad class of polymers noted for good abrasion and solvent
resistance. Can be in solid or cellular form. |
|
| Polyvinylchloride |
|
A general purpose thermoplastic used for wire and cable insulation
and jackets. |
|
| Power |
|
The amount of work per unit of time. Usually expressed in
watts and equal to I2R. |
|
| Power Ratio |
|
The ratio of power appearing at the load to the input power.
Expressed in DB, it is equal to 10 log10 (P1/P2) where P1 is
input power and P2 is the power at that load. |
|
| Printed Circuit Board (PCB) |
|
An epoxy glass and metal composite on which circuits are etched
and to which active, passive and hardware components are attached.
Also called a PCB or PC board. |
|
PTFE
(Polytetrafluoroethylene) |
|
The thermally most stable and chemically most resistant carbonaceous
compound. It is unaffected by sunlight, moisture, and virtually
all chemicals. Temperature range is -200℃ to +260 ℃ / -392ßF
to +500ßF. Electrical properties are very constant over temperature
and a wide of frequencies. |
|
| Pulse |
|
A change in the level, over a relatively short period of time,
of a signal whose value is normally constant. |
|
| Pulse Width |
|
The length of time that the pulse voltage is at the transient
level. Electronic pulse widths are usually in the millisecond
(10-3), microsecond(10- 6) or nanosecond(10-9) range. |
|
| PVC |
|
Polyvinylchloride. |
|
