The Illustrated Dictionary of Electronics - Loscha

538 plated-wire memory • plate-type capacitorplated-wire memory See WIRE MEMORY.plate-grid capacitance Symbol, C PG or C GP . Unit,pF. The internal capacitance between the plateand control grid of an electron tube. Also calledINTERELECTRODE CAPACITANCE and FEED-BACK CAPACITANCE.plate load The power-consuming load into whichthe plate circuit of an electron tube operates. Inan intermediate stage of a multistage amplifier,this load is the grid circuit of the following tube.plate load impedance Symbol, Z LP . Unit, ohm. In atube circuit, the (output) impedance that is acconnectedbetween the plate and ground, or dcconnectedbetween the plate electrode and dcplate power supply.plate meter A direct-current ammeter or milliammeterthat indicates the plate current of anelectron tube.plate modulation A method of AMPLITUDE MOD-ULATION in which a modulating voltage is superimposedon the direct-current plate voltage of ahigher-frequency amplifier or oscillator.platen The “roller” in a teletypewriter or impactprinter. It supports the paper against impact bythe print head; it also helps to move the paperthrough the machine.plate-neutralized amplifier A vacuum-tube radiofrequencypower amplifier in which a neutralizingcapacitor is connected between the control gridand the free end of a center-tapped plate-tankcoil.plate power Symbol, P P . Unit, watt. Power in theplate circuit of an electron tube; P P = E P I P , whereE P is the plate voltage in volts and I P is the platecurrent in amperes.plate power input See PLATE POWER.plate power output The output signal power deliveredby the plate circuit of an electron tube. ComparePLATE POWER INPUT.plate power supply The (usually direct current)power supply that furnishes energy to the plate ofan electron tube.plate pulse modulation A method of obtainingpulse modulation by injecting high-voltage pulsesinto the plate circuit of a vacuum-tube amplifier.plate relay A relay operated in series with the plateof an electron tube.plate resistance Symbol, r P . Unit, ohm. Resistanceof the internal plate circuit of an electron tube.The static value of r P is equal to E P /I P , where E P isthe plate voltage in volts, and I P is the plate currentin amperes. The dynamic value is dE P /dI P .plate saturation In an electron tube, the point atwhich, while plate voltage is increasing, the plateattracts all the electrons emitted by the cathode(i.e., the point beyond which no further significantincrease in plate current results from a furtherincrease in plate voltage).plate-screen capacitance Symbol, C PS . Unit, pF.The internal capacitance between the plate andscreen grid of an electron tube.plate-screen modulation A method of AMPLI-TUDE MODULATION in which the modulatingvoltage is superimposed simultaneously on thedirect-current plate and screen voltages of ahigher-frequency amplifier or oscillator.plate series compensation In an audio amplifier,the use of a plate decoupling circuit to obtain afixed amount of bass boost.plate shunt compensation The addition of a networkto the plate-output circuit of a tube to boostthe bass response of an amplifier.plate spacing 1. The distance between plates in afixed capacitor. This dimension is usually thesame as dielectric thickness. 2. The distance betweenplates in a variable capacitor. Also calledcapacitor air gap.PlatespacingPlateplate spacing, 1PlateDielectricplate supply voltage Symbol, E BB . The output voltageof a plate power supply.plate tank A resonant inductance-capacitance(LC) circuit operated from the plate of an electrontube.plate tank capacitance The capacitance requiredto tune a PLATE TANK to resonance.plate tank inductance The inductance of the coilin a PLATE TANK.plate tank Q Figure of merit (see Q) of a plate tank,a function of the load resistance and the tank inductance-to-capacitance(L/C) ratio.plate tank voltage The audio-frequency or radiofrequencyvoltage developed across the plate tankof an electron-tube circuit.plate tuning Tuning an electron-tube circuit byvarying the capacitance, inductance, or both inthe plate tank.plate tuning capacitance See PLATE TANK CA-PACITANCE.plate tuning inductance See PLATE TANK IN-DUCTANCE.plate-type capacitor A capacitor having flat metalplates, rather than concentric cylinders, a cylinderand rod, etc.