User:Brews ohare

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I am new to Wikipedia, but have made a few contributions so far. Some of the illustrations I've added are below. They show my interests are in circuits and devices. I've also originated several articles that remain in their initial state so far: Pole splitting, Return ratio, Signal-flow graph, Nullor, Ampere's force law; and completely rewritten Step response, Current mirror, Active load, Free space and Value judgment. The Wikipedia editing and posting environment is really nice to work with. Finding out how things work is not so easy, and editors help here a lot. I've had some run-ins with editors, mostly constructive and civilized, and I am most happy to acknowledge the editing assistance of User:Rogerbrent and User:Dicklyon. I'm also happy to report a happy collaboration with User:Sbyrnes321 on the article Faraday's law of induction, which proved to be a rather unique example of cooperative evolution.

Circuit 1 with current I1 exerts force F12 on Circuit 2 via its B-field B1, and conversely
Circuit 1 with current I1 exerts force F12 on Circuit 2 via its B-field B1, and conversely


Figure 1: Ideal negative feedback model; open loop gain is AOL and feedback factor is β.
Figure 1: Ideal negative feedback model; open loop gain is AOL and feedback factor is β.
Figure 2: Conjugate pole locations for step response of two-pole feedback amplifier; Re(s) = real axis and Im(s) = imaginary axis.
Figure 2: Conjugate pole locations for step response of two-pole feedback amplifier; Re(s) = real axis and Im(s) = imaginary axis.
Figure 3: Step-response of a linear two-pole feedback amplifier; time is in units of 1/ρ, that is, in terms of the time constants of AOL; curves are plotted for three values of mu = μ, which is controlled by β.
Figure 3: Step-response of a linear two-pole feedback amplifier; time is in units of 1/ρ, that is, in terms of the time constants of AOL; curves are plotted for three values of mu = μ, which is controlled by β.
Figure 4: Miller capacitance at low frequencies CM (top) and compensation capacitor CC (bottom) as a function of gain using Excel. Capacitance units are pF.
Figure 4: Miller capacitance at low frequencies CM (top) and compensation capacitor CC (bottom) as a function of gain using Excel. Capacitance units are pF.
Figure 2: Gain vs. frequency for a single-pole amplifier with and without feedback; corner frequencies are labeled.
Figure 2: Gain vs. frequency for a single-pole amplifier with and without feedback; corner frequencies are labeled.
Figure 6: Circuit set-up for finding feedback amplifier input resistance
Figure 6: Circuit set-up for finding feedback amplifier input resistance
As channel length decreases, the barrier φB to be surmounted by an electron from the source on its way to the drain reduces
As channel length decreases, the barrier φB to be surmounted by an electron from the source on its way to the drain reduces
Figure 6: Gain of feedback amplifier AFB in dB and corresponding open-loop amplifier AOL. Parameter 1/β = 58 dB, and at low frequencies AFB ≈ 58 dB as well. The gain margin in this amplifier is nearly zero because | βAOL| = 1 occurs at almost f = f180°.
Figure 6: Gain of feedback amplifier AFB in dB and corresponding open-loop amplifier AOL. Parameter 1/β = 58 dB, and at low frequencies AFB ≈ 58 dB as well. The gain margin in this amplifier is nearly zero because | βAOL| = 1 occurs at almost f = f180°.
Figure 5: Small-signal circuit with two-port for feedback network; upper shaded box: main amplifier; lower shaded box: feedback two-port replacing the L-section made up of Rf and R2.
Figure 5: Small-signal circuit with two-port for feedback network; upper shaded box: main amplifier; lower shaded box: feedback two-port replacing the L-section made up of Rf and R2.
MOSFET showing shallow junction extensions, raised source and drain and halo implant
MOSFET showing shallow junction extensions, raised source and drain and halo implant
Figure 3: A possible signal-flow graph for the asymptotic gain model
Figure 3: A possible signal-flow graph for the asymptotic gain model
Bands in graded heterojunction npn bipolar transistor. Barriers indicated for electrons to move from emitter to base, and for holes to be injected backward from base to emitter; Also, grading of bandgap in base assists electron transport in base region; Light colors indicate depleted regions
Bands in graded heterojunction npn bipolar transistor. Barriers indicated for electrons to move from emitter to base, and for holes to be injected backward from base to emitter; Also, grading of bandgap in base assists electron transport in base region; Light colors indicate depleted regions
Figure 1: Operational amplifier with compensation capacitor CC between input and output; notice the amplifier has both input impedance Ri and output impedance Ro.
Figure 1: Operational amplifier with compensation capacitor CC between input and output; notice the amplifier has both input impedance Ri and output impedance Ro.
Figure 2: Operational amplifier with compensation capacitor transformed using Miller's theorem to replace the compensation capacitor with a Miller capacitor at the input and a frequency-dependent dependent current source at the output.
Figure 2: Operational amplifier with compensation capacitor transformed using Miller's theorem to replace the compensation capacitor with a Miller capacitor at the input and a frequency-dependent dependent current source at the output.
MOSFET version of gain-boosted current mirror; M1 and M2 are in active mode, while M3 and M4 are in Ohmic mode, and act like resistors. The operational amplifier provides feedback that maintains a high output resistance
MOSFET version of gain-boosted current mirror; M1 and M2 are in active mode, while M3 and M4 are in Ohmic mode, and act like resistors. The operational amplifier provides feedback that maintains a high output resistance


Figure 1. Top: pnp base width for low collector–base reverse bias; Bottom: narrower pnp base width for large collector–base reverse bias. Light colors are depleted regions.
Figure 1. Top: pnp base width for low collector–base reverse bias; Bottom: narrower pnp base width for large collector–base reverse bias. Light colors are depleted regions.


Figure 4: Bode magnitude plot for pole-zero combination; the location of the zero is ten times higher than in Figures 2&3; curves labeled "Bode" are the straight-line Bode plots
Figure 4: Bode magnitude plot for pole-zero combination; the location of the zero is ten times higher than in Figures 2&3; curves labeled "Bode" are the straight-line Bode plots
Figure 5: Bode phase plot for pole-zero combination; the location of the zero is ten times higher than in Figures 2&3; curves labeled "Bode" are the straight-line Bode plots
Figure 5: Bode phase plot for pole-zero combination; the location of the zero is ten times higher than in Figures 2&3; curves labeled "Bode" are the straight-line Bode plots
Figure 2: A vector field F ( r, t ) defined throughout space, and a surface Σ bounded by curve ∂Σ moving with velocity v over which the field is integrated.
Figure 2: A vector field F ( r, t ) defined throughout space, and a surface Σ bounded by curve ∂Σ moving with velocity v over which the field is integrated.
Figure 4: An example, based on one of Feynman's examples, where Faraday's law does not work. A rectangle of photoconductive material slides along a pair of wires. At a fixed location a strong light and a strong magnetic field create a narrow immovable strip of conducting material subject to a Lorentz force.
Figure 4: An example, based on one of Feynman's examples, where Faraday's law does not work. A rectangle of photoconductive material slides along a pair of wires. At a fixed location a strong light and a strong magnetic field create a narrow immovable strip of conducting material subject to a Lorentz force.
Figure 4: Faraday's disc electric generator. The disc rotates with angular rate ω, sweeping the conducting radius circularly in the static magnetic field B. The magnetic Lorentz force v × B drives the current along the conducting radius to the conducting rim, and from there the circuit completes through the lower brush and the axle supporting the disc. Thus, current is generated from mechanical motion.
Figure 4: Faraday's disc electric generator. The disc rotates with angular rate ω, sweeping the conducting radius circularly in the static magnetic field B. The magnetic Lorentz force v × B drives the current along the conducting radius to the conducting rim, and from there the circuit completes through the lower brush and the axle supporting the disc. Thus, current is generated from mechanical motion.


Figure 3: Mapping of the Faraday disc into a sliding conducting rectangle example. The disc is viewed as an annulus; it is cut along a radius and bent open to become a rectangle.
Figure 3: Mapping of the Faraday disc into a sliding conducting rectangle example. The disc is viewed as an annulus; it is cut along a radius and bent open to become a rectangle.
Figure 2: Rectangular wire loop in magnetic field B moving along x-axis at velocity v.
Figure 2: Rectangular wire loop in magnetic field B moving along x-axis at velocity v.
Figure 3: A ball moving vertically along the axis of rotation in an inertial frame appears to spiral downward in the rotating frame. The right panel shows a downward view in the rotating frame.
Figure 3: A ball moving vertically along the axis of rotation in an inertial frame appears to spiral downward in the rotating frame. The right panel shows a downward view in the rotating frame.
Figure 1: An object located at xA in inertial frame A is located at location xB in accelerating frame B. The origin of frame B is located at XAB in frame A. The orientation of frame B is determined by the unit vectors along its coordinate directions, uj with j = 1, 2, 3. Using these axes, the coordinates of the object according to frame B are xB = ( x1, x2, x3 ).
Figure 1: An object located at xA in inertial frame A is located at location xB in accelerating frame B. The origin of frame B is located at XAB in frame A. The orientation of frame B is determined by the unit vectors along its coordinate directions, uj with j = 1, 2, 3. Using these axes, the coordinates of the object according to frame B are xB = ( x1, x2, x3 ).
Figure 4: Left panel: Ball on a banked circular track moving with constant speed v; Right panel: Forces on the ball. The resultant or net force on the ball found by vector addition of the normal force exerted by the road and vertical force due to gravity must equal the centripetal force dictated by the need to travel a circular path.
Figure 4: Left panel: Ball on a banked circular track moving with constant speed v; Right panel: Forces on the ball. The resultant or net force on the ball found by vector addition of the normal force exerted by the road and vertical force due to gravity must equal the centripetal force dictated by the need to travel a circular path.
Figure 2: Car with passenger making a turn. The road exerts a centripetal force on the car to force a curved path. Apparently the passenger is facing backwards; hopefully they are not driving.
Figure 2: Car with passenger making a turn. The road exerts a centripetal force on the car to force a curved path. Apparently the passenger is facing backwards; hopefully they are not driving.
Figure 3: Exploded view showing force components. Each object is subject to a net inward force that is the difference between the outward reactive centrifugal force and an inward centripetal force. This net inward force is the centripetal force upon that object necessary for it to make the turn. (Torque is ignored here, for simplicity.)
Figure 3: Exploded view showing force components. Each object is subject to a net inward force that is the difference between the outward reactive centrifugal force and an inward centripetal force. This net inward force is the centripetal force upon that object necessary for it to make the turn. (Torque is ignored here, for simplicity.)
Integration over the triangular area can be done using vertical or horizontal strips as the first step. The sloped line is the curve y = x.
Integration over the triangular area can be done using vertical or horizontal strips as the first step. The sloped line is the curve y = x.
Coordinate system at latitude φ with x-axis east, y-axis north and z-axis upward (that is, radially outward from center of sphere).
Coordinate system at latitude φ with x-axis east, y-axis north and z-axis upward (that is, radially outward from center of sphere).