In the 1950s negative impedance gain devices were more popular, and a transistorized version called the E6 repeater was the final major type used in the Bell System before the low cost of digital transmission made all voiceband repeaters obsolete.

( The control grid draws no current while negative — high impedance — but draws current while positive — low impedance.

) With the control grid operating entirely in the negative region, and with the RF shielding afforded by the screen grid, tetrode input impedance is quite high even at high frequencies.

* Negative impedance converter, configuration of an operational amplifier which acts as a negative load

The typical true negative impedance circuit — the negative impedance converter – is due to John G. Linvill ( 1953 ) and the popular element with negative differential resistance — the tunnel diode – is due to Leo Esaki ( 1958 ).

The negative resistance circuit shown in Figure 3 is an opamp implementation of the negative impedance converter ( see below ).

This is also known as negative impedance.

It is not uncommon for an antenna containing multiple driven elements to exhibit apparent negative impedance in one or more of the driven elements.

Some circuits and elements exhibiting negative resistance can also act in a similar way: negative impedance converters ( NIC ), neon lamps, tunnel diodes ( e. g., a diode with an " N "- shaped current – voltage characteristic in the first quadrant ), etc.

The loss tangent is defined by the angle between the capacitor's impedance vector and the negative reactive axis.

When representing the electrical circuit parameters as vectors in a complex plane, known as phasors, a capacitor's dissipation factor is equal to the tangent of the angle between the capacitor's impedance vector and the negative reactive axis, as shown in the diagram to the right.

The " Valvestate " mode introduces negative current feedback which raises the output impedance, lowers the damping factor, and alters the frequency response, similarly to what occurs in a tube amplifier.

For example, in general a generator will have different positive and negative sequence impedance, and certain transformer winding connections block zero-sequence currents.

1 there ), the Howland current source consists of an input voltage source V < sub > IN </ sub >, a positive resistor R, a load ( the capacitor C acting as impedance Z ) and a negative impedance converter INIC ( R < sub > 1 </ sub >

If the cathode resistor is unbypassed, negative feedback is introduced and each half of a 12AX7 provides a typical voltage gain of about 30 ; the amplification factor is basically twice the maximum stage gain, as the plate impedance must be matched.

This negative resistance effect requires that some positive form of impedance — an electrical ballast — to be placed in the circuit, to maintain a stable arc.

It is an inverting converter, so the output voltage is negative with respect to the input voltage.

By applying a negative feedback ( simply joining the base and collector ) the transistor can be " reversed " and it will begin acting as the opposite logarithmic current-to-voltage converter ; now it will adjust the " output " base-emitter voltage so as to pass the applied " input " collector current.

If the input voltage varies, this arrangement will act as a voltage-to-current converter ( voltage-controlled current source VCCS ); it can be thought as a reversed ( by means of negative feedback ) current-to-voltage converter.

The two versions obtained are accordingly a negative impedance converter with voltage inversion ( VNIC ) and a negative impedance converter with current inversion ( INIC ).

By using an NIC as a negative resistor, it is possible to let a real generator behave ( almost ) like an ideal generator, ( i. e., the magnitude of the current or of the voltage generated does not depend on the load ).

All such imitations of negative quality have given rise to a compensatory response in the form of a heroic and highly individualistic humanism: if man can neither know nor love reality as it is, he can at least invent an artistic `` reality '' which is its own world and which can speak to man of purely personal and subjective qualities capable of being known and worthy of being loved.

In its place is a passionate consciousness grasped and molded to feelings of positive or negative values even as the actions of one's life are determined by constellations of process in which one is caught.

But it is a clumsy and wasteful process: it can produce negative results but not much that is positive.

To this end political authority is called upon to exercise its negative and coercive powers.

It is not difficult to anticipate circumstances in which negative tensions will cumulate ; ;

It is presumed that this negative head was associated with some geometric factor of the assembly, since different readings were obtained with the same fluid and the only apparent difference was the assembly and disassembly of the apparatus.

This negative pressure is not explained by the velocity head Af since this is not sufficient to explain the readings by several magnitudes.

As Loomis remarks, `` In the internal pattern the chief reason for interacting is to communicate liking, friendship, and love among those who stand in supporting relations to one another and corresponding negative sentiments to those who stand in antagonistic relations ''.

In theory, compulsive behavior is a way of diminishing anxiety, and one might expect a negative association except for the possibility that for many children the obsessive-compulsive defenses are not sufficient to quell the amount of anxiety they suffer.

His first conclusion, on behavior of individual items, is negative, whereas mine ( on Ath. and Yok. ) was partially positive.

My answer is in the negative because I believe that total capital demands during the Sixties will continue to press against available supplies, and interest rates will generally tend to be firm at high levels.

Because the rake angle Af at the tip of the knife is very much smaller ( or even negative ) when compared to the value of **yc for the major portion of the knife, a very rapid increase in cutting force with thickness will result.

The first is a negative warning: there is no point in the creation of faculty committees and advisory boards with high-sounding titles but no real authority.

The concept of unity, in which positive and negative are attributes of the same force, in which good and evil are relative, ever-changing, and always joined to the same phenomenon -- such a concept is still reserved to the physical sciences and to the few who have grasped the history of ideas.

Remember, when the little hand is straight up that's negative.

In the context of larger ethical discussions on moral action and judgment, Buddhism is characterized by the belief that negative ( unhappy ) consequences of our actions derive not from punishment or correction based on moral judgment, but from the law of karma, which functions like a natural law of cause and effect.

Since pH is defined as the negative logarithm of the concentration of hydronium ions, acids thus have pHs of less than 7.

However, in hydrogen astatide ( HAt ) the negative charge is predicted to be on the hydrogen atom, implying that this compound should instead be referred to as astatine hydride.

An atom containing an equal number of protons and electrons is electrically neutral, otherwise it has a positive charge if there are fewer electrons ( electron deficiency ) or negative charge if there are more electrons ( electron excess ).

The electron is by far the least massive of these particles at, with a negative electrical charge and a size that is too small to be measured using available techniques.