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Questions tagged [negative-resistance]

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2 votes
3 answers
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Why can't the following configuration be considered negative feedback?

In the following circuit I have kept the resistor ratio such that beta factor of negative terminal (part of output will come on inverting terminal by voltage division), is higher than that of positive ...
needbrainscratched's user avatar
1 vote
5 answers
189 views

How does a signal get amplified? [closed]

Say I send an analog electric signal through a telephone wire. If that wire is long enough then the resistance will eventually make the amplitude of the signal close to zero. How do electric signals ...
Waterbloo's user avatar
  • 349
9 votes
7 answers
2k views

Creating a circuit with negative differential resistance

Is it possible to construct a circuit with negative differential resistance by only using components that have no negative differential resistance (e.g., resistors, diodes, BJTs, etc)? If possible, ...
Firman's user avatar
  • 193
0 votes
2 answers
232 views

Using tunnel diode to cancel out armature resistance

Can we use tunnel diodes to cancel out armature resistance? A tunnel diode when it is in its negative differential region under DC shifted AC(AC with some DC offset) and if the Vp-p of the AC is very ...
Root Groves's user avatar
0 votes
0 answers
20 views

NIC network circuit with grounded output?

My class was given a series of circuit networks to calculate the transmission of the system. One of those networks is this type of Negative Impedance Converter with the common ground output. How can I ...
BadApples_'s user avatar
1 vote
2 answers
139 views

Powering a negative resistance converter with an Arduino power pin

I want to build a negative resistance converter and the only voltage source I have is a 5 V Arduino power pin. I am afraid the reverse current (Is) flowing through the power pin will destroy my ...
Reinhardt Walzer's user avatar
3 votes
1 answer
153 views

Compensate potentiometer wiper resistance with negative resistance (LM358)

I'm trying to cancel wiper resistance of a 10 kΩ DiGiPot that controls output voltage of a switching power supply. I'm using MCP4131-103 that has 120 Ω wiper resistance @0% pot position. This wiper ...
AKTanara's user avatar
  • 291
0 votes
0 answers
37 views

How to add a voltage control to this frequency dependent negative resistor circuit?

I would like to control the filter frequency with a control voltage. I assume that resistors R17,18,19 and 24 must be replaced with a adequate sub circuit. Could someone advice me where should I start ...
Jerzy Przezdziecki's user avatar
-1 votes
1 answer
245 views

Negative resistance - crystal

Why do we have the negative resistance concept in a crystal? How does the crystal exhibit negative resistance? I've read this Link and it seems to say that the amplifier is the one that causes the ...
user avatar
4 votes
4 answers
745 views

0 current in a circuit using tunnel diode

Suppose we have a diode with negative differential resistance of -40 ohm in the region of 0.3-0.5 V and we put it in parallel with a 40 ohm resistor: simulate this circuit – Schematic created ...
Jun Seo-He's user avatar
0 votes
2 answers
466 views

Why does this negative impedance converter (NIC) circuit work in an LTspice simulation but not in an actual circuit?

I've been trying to invert the phase response of a non-inverting low pass filter by using a "negative resistor" (-5000 ohms,) which is achieved by the simulation below (bode plot + circuit): ...
tupsman's user avatar
4 votes
4 answers
3k views

Magical uses of tunnel diodes

I am studying the working principle of tunnel diode and I am reading for a voltage range it creates a negative differential resistance. If we have a current source supplying the circuit with some ...
Miss Mulan's user avatar
2 votes
4 answers
259 views

Negative resistance in a regenerative radio receiver?

Why is an amplifier with a tuned circuit and positive feedback, such as a regenerative radio receiver, said to exhibit or have negative resistance?
hotpaw2's user avatar
  • 4,831
8 votes
5 answers
1k views

How to make/describe an element with negative resistance of minus 1 Ohm?

How do I make/describe an element with negative resistance of minus 1 Ohm? It's I–V characteristic should then be \$I = -U\$ Is this possible? I need exactly what I wrote. No compromises. The ...
Dims's user avatar
  • 535
3 votes
2 answers
709 views

Circuit LTspice implementation not working

I stumbled upon on Chua circuit and tried to implement it LTspice. This was allegedly supposed to be a double scroll, however upon simulating it in LTspice I achieve a different result. Here you can ...
kepsek's user avatar
  • 75
4 votes
2 answers
1k views

Negative resistance from MOSFET circuit

From the paper https://ir.nctu.edu.tw/bitstream/11536/5095/1/A1979JE36000027.pdf I'm trying to understand this MOSFET circuit which creates negative resistance. Whilst the paper explores how it works, ...
kepsek's user avatar
  • 75
0 votes
2 answers
541 views

How is this circuit a negative resistance oscillator

I found these oscillator configurations(all are similar) at various sites on the web, but here and here the author says its a negative resistance oscillator. It's a popular oscillator among amateur ...
User's user avatar
  • 849
13 votes
1 answer
3k views

Stability of input filter in SMPS - Theoretical explanation

I read the Application note Wurth Electronics ANP008c about negative resistance of a SMPS input and how to avoid oscillation when using an input LC filter. I'm asking for a theorethical clarification ...
Alessio Caligiuri's user avatar
2 votes
1 answer
363 views

Compensate potentiometer wiper resistance with negative resistance [duplicate]

Is it possible to compensate a digital potentiometer's 75 ohm wiper resistance with a negative resistance amplifier?
user3476707's user avatar
0 votes
1 answer
88 views

How was this equation derived for a L-C negative resistance oscillator?

I'm looking over some old notes and saw this series of equations for a L-C oscillator. The first step is just writing a KCL equation for the circuit: $$ \frac{V}{-R}+sCV+\frac{V}{sL+r}=0 $$ Where \$s=...
yilod12175's user avatar
0 votes
1 answer
392 views

Attenuating op-amp circuit with offset

I am designing a non-inverting op-amp circuit that maps an input signal (V3) 0-3.3V to an output signal (Vo) 0.2-2.4V. I opted to offset the output up by 0.2V and then used a second op-amp circuit as ...
illancha's user avatar
3 votes
3 answers
554 views

Negative resistance circuit

The circuit is inputted with a 200Hz sine wave and the amplitude is varied. I believe the circuit is operating with negative feedback. But also the 8.2K resistor is then switched to an 18K resistor in ...
mwilliams25's user avatar
4 votes
5 answers
5k views

Is negative resistance possible?

I was reading Hayt Kemmerly Engineering Circuit Analysis Book,(I tried others, but this is the most comprehensible to me.), And I came across this circuit. I understand the first two, but I don't ...
Angular Orbit's user avatar
1 vote
2 answers
684 views

Is it possible to reduce the resistance of a voltage source (coil)? If yes, how can I do that? [closed]

First, I should inform you that I am a mechanical engineer, so this is an adventure to me. What can sound as basic to you, is like a new discovery for me. Second, I would like to introduce you the ...
Willian MK's user avatar
0 votes
2 answers
391 views

Is static negative resistance practically available?

I learned that negative resistance (NR) could be simulated by involving active devices like op-amps and others. I'm interested in the static/absolute NR rather than the differential NR. My question is ...
xiaohuamao's user avatar
2 votes
2 answers
2k views

Oscillator circuit with a Negistor

I am trying to do some experiments with the following oscillator circuit extracted from http://jlnlabs.online.fr/cnr/negosc.htm based on Esaki oscillator. I am using 2N2222 and a 10mH inductor ...
Pojj's user avatar
  • 868
1 vote
2 answers
811 views

UJT Negative Resistance and Ohm's Law

A Unijunction Transistor has a negative resistance region where voltage drops with an increase in current. This was explained to me as a situation where "Ohm's Law is broken". This doesn't sit well ...
Trevor's user avatar
  • 11
1 vote
1 answer
361 views

Negative-Gm Oscillator Biasing Conditions

I have some questions regarding the circuit below. I need to ensure two conditions are met. The output is taken from the drains of the cross-coupled pair. I think the drain voltages (1.198V) are not ...
user367640's user avatar
0 votes
1 answer
255 views

Negative Effective Resistance

Assume that we have a circuit that is connected with components that have positive resistance. At this point the effective resistance between every two node is positive. (below is an example of such ...
user114313's user avatar
0 votes
4 answers
778 views

How does a magnetic ballast (large inductor) stabilize a negative resistive circuit (such as a fluorescent light)?

When reading about fluorescent lights, I noted many sources stating that a large inductor (the magnetic ballast) in series with a negative resistor (the light, in this case) will stabilize it by ...
Nicholas Moehle's user avatar
0 votes
2 answers
905 views

Neon lamps in parallel DC

I am making a nixie clock and wanting to use 2 neon lamps in parallel for each colon. However in my test circuit I can only get one to strike at a time. The supply voltage is 170Vdc in order to power ...
Ty Hayes's user avatar
  • 103
1 vote
1 answer
290 views

How to simulate adjustable 'negative resistance' with active components?

I'm building a decade resistance box using 2W resistors, from 10x1M ohm to 10x0.1 ohm. However, due to some contact resistance, the 0.1 to 1 ohm resistance will likely turn out to be ~1.1 ohm to 2 ...
Ehryk's user avatar
  • 1,181
1 vote
2 answers
741 views

A questions about negative resistance?

I would like to look at negative resistance from a practical point of view, not just theory. Would you answer my questions,please? The op-amp, R1, R2, and R3 behave as a negative resistance: Rn = - ...
Michael George's user avatar
7 votes
6 answers
3k views

Negative resistance, impact on voltage source?

According to this, if \$R_1=R_2=R\$ then input resistance is \$R_{in}=-R_3\$, and if we assume that op amp is ideal. So negative resistance is in parallel with voltage source \$V_s\$. Am I understand ...
Zippi's user avatar
  • 305