Questions tagged [bipolar]
The bipolar tag has no usage guidance.
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Adjustable power resistance
I have to design a circuit that must draw up to 1200 W on 12 VDC to 40 VDC, maximum 50 A, during 100 ms and be adjustable.
The first approach was to use power resistors (LTO100) of several values, ...
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Is this behavior realistic for bipolar loads on optocoupler outputs?
Background:
When using LTspice to simulate such a circuit (the opto-model is called PC357NT and is part of some exhaustive lib called "ZZZ" which I downloaded a long time ago. The PC357NT ...
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Why is bipolar capacitor labelled with plus and minus?
I need an unpolarised 3300 uF capacitor for an audio amplifier. After googling on the internet, I came to the conclusion that the only way to get such a high value is to use a so-called bi-polar ...
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Using MOSFET to prevent short circuit
I have a circuit where a charger loads a 24 V battery. When the charger is not plugged, there is a risk that of short circuit and the battery will then explode. To avoid this I thought about using ...
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Active load and current source purpose on NE5532
I'm trying to do some reverse engineering on the NE5532 schematic, but I can't understand how is designed the current source for the first stage. What I want to analyze now is in yellow on the picture....
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Active load role on this circuit and possible uses
simulate this circuit – Schematic created using CircuitLab
I came with this circuit to know how an active load can improve it, I still can't finish to understand the role of active loads. The ...
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We fabricate P-type and N-type Schottky diodes and a P-type Schottky diode; can a PN-junction diode and PNP BJT be formed?
A Schottky diode is a unipolar device. If a P-type Schottky diode is fabricated on an N-type Schottky diode, can we make a PN-junction diode and a PNP transistor?
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Layperson asking intuitive question about bipolar junction transistor
I am a layperson trying to understand how the bipolar junction transistor works from this excellent article: https://spectrum.ieee.org/transistor-history
The relevant paragraphs are as follows:
...
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Bipolar calculations with unkown resistor values and unknown current values
Having a hard time figuring out the current and resistor values across resistor Rf and Rc in an NPN germanium transistor. How do I calulate the current across the collector of the transistor with ...
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Is there a problem with my circuit?
The problem is that the curve of the collector's current decreases after reaching a certain (or saturation) point. Should it be this way or there is a problem with LTspice?
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Grounding a bi polar high voltage pulser
This was a "brain teaser" in a circuits class, where only theory is required. Any equations or vocabulary to look into would be greatly appreciated. The question is the following:
You are ...
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ADS1113 ADC saturation at 0 Volts while sampling bipolar signal
I'm using a ADS1113 delta-sigma 16-bit ADC to sample a bipolar signal from a force sensor at 50Hz, and I have found a weird phenomenon.
When the signal negative or positive, there is no issue, but ...
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Creating bi-polar signal from IC's
I'm trying to create a bi-polar square wave from a flip flop but all I get is a positive result. It never goes below GND. I know the second (lower) transistor gets positively biased and maybe this is ...
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What does the cross point of V-I curves mean?
Here you see a V-I graph including many curves achieved under different junction temperatures of an IGBT. As it can be seen there is a cross point where all curves intersect each other. Does it make ...
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Pulse oximeter design: How to drive a bi-polar LED having two different forward voltages?
My lab partner and I are building a pulse oximeter for our capstone project and could use some help.
I have an ELM-4002 which is a bipolar LED with the following specifications. The two LEDs are ...
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BJT vs MOSFET switching speed
I've been reading various answers about the switching speed and frequency of BJTs and MOSFETs, yet I keep finding conflicting answers. Can anyone explain the discrepancy and the real answer? Sources ...
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Is the power consumption of field effect transistors lower than that of bipolar transistors, and why? [duplicate]
Is the power consumption of field effect transistors lower than that of bipolar transistors, and why?
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Basic electronics: Transistor switch
I am new to electronics. I am reading this book called Practical Electronics for Inventors.
This is a portion about bipolar transistors from the book:
There are two things I don't get from this:
...
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Physics of bipolar transistor turn-off
In a class AB follower push pull amplifier output stage* operated open loop and driven from a low impedance source, these are, from top to bottom, the emitter currents of both transistors, their ...
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Proving that this JFET + Bipolar source follower give back a linear output
I was reading about this source follower and wondered how the bipolar transistor makes Vgs somewhat stable.
I believe that what happens here is that when Vin is high more current flows through the ...
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Where can I find the symbolic symbols of various bipolar, JFET, MOSFET in a *unified* style?
Where can I find the symbolic symbols of various bipolar, JFET, MOSFET in a unified style ?
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Diode in feedback path of transistor (collector-base)?
This is the schematic for a fuzz circuit. Even knowing that the diode is probably what's providing the signal clipping, I still can't figure out how I'm supposed to analyze the circuit.
When V(...
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Noise reduction in ECL logic gates
In this ECL circuit, how he got the equivalent circuit for the noise voltage and what is the meaning of hib4 in the equivalent circuit.
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Qualitative explaination of Output Characteristic of Transistor (BJT) using Depletion layer between Collector and Base
From my understanding,
The diffusion layer at a p-n junction is an equilibrium of two opposing forces on charge carriers due to 2 forces - Concentration Gradient and Electric Field caused by Bias and ...
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Parallel Caps as a Bipolar (twin polar in combination)
So, I saw a similar question about 2 caps in series to make a bipolar.
Lets assume polar electrolytics
I pretty much "get" electronics and build stuff - it works as I expect mostly.
I have ...
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Generate +/- voltage outputs using two boost converters?
I am working on a project to power some audio equipment that requires +/- 15V DC. Output current load is about 250mA, maximum. I am wondering if there’s any reason I couldn’t create this using two ...
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How do I compute the gain on this differential amplifier (in an open loop)?
Hello! I've got this project due for a college course, and the teacher has reviewed my work and said that it is within specification, but he asked me to compute the gain the good old fashioned way ...
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What voltage or node are the BJT substrates connected to in a bipolar process opamp IC?
I've been recently experimenting with converting transistor-level SPICE models of ICs into subcircuits. One thing I try to keep consistent with my subcircuits is that they remain floating; i.e. no ...
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Why are bipolar transistors used for switching applications?
I noticed that many sites targeted at hobbyists recommend bipolar transistors (mostly NPN) to switch things on and off. Bipolar transistors definitely have their purposes especially in analog circuits,...
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How does bipolar line coding such as AMI work with medium like fiber optics
We know that in bipolar encoding (sometimes called multilevel binary), there are three voltage levels: positive, negative, and zero. The voltage level for one data element is at zero, while the ...
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Why bipolar encoding such as AMI is called bipolar?
In bipolar encoding, we use three levels: positive, zero, and negative. The voltage level for one data element is at zero, while the voltage level for the other element alternates between positive and ...
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Why doesn't this Colpitts oscillator design work?
falstad schematic link
My setup:
I made many attempts at building a Colpitts oscillator, and this one by far supposed to be the most advanced and with high chance of success.
Yet, it's still ...
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Bipolar RC Oscillator does not oscillate
Falstad schematic and simulation
VCC is 9V.
I made hardware version of this first (didn't put too much effort in this simulation) and it's not working. I could read about 3-4 V on CE, so transistor ...
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Bipolar capacitor replacement with very different dimension
I need to replace a 25VNP / 10MFD bipolar capacitor (the gray one in the picture).
I have a 35VNP / 10MFD (bipolar) capacitor replacement. However it's very small compared to the 25VNP one. The gray ...
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BJT reverse active currents
My question is on bipolar junction transistors, NPN with 2 emitters, as used in TTL NAND gates.
When in reverse active mode, and when the 2 emitter are logic high, how is the collector current ...
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How does Bipolar junction transistor amplifies the voltage? [duplicate]
I was looking at Operational amplifier recently, so if you look at the diagram for op-amp, it's just a bunch of npn and pnp junctions. But how could they come together and work as a voltage amplifier ...
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Why are circuit results different from theorised?
From the following circuit:
I got the following results in comparison to my theorized calculations:
Why were my result different to my calculations?
Here is my calculations:
Equipment used:
...
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Calculating Nmax in loaded bipolar junction transistor inverter
I have tried various methods for calculating N max here, and some have resulted in negative answers while others have resulted in an answer of around 1.
Is my method correct? Or am I missing ...
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Bipolar Transistor Inverter Circuit Analysis
I have been trying to understand this question and I'm just not sure what equation to use for the collector current.
I'm not sure if I need to be using an output voltage function of time?
All I have ...
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PNP Open Collector output series resistor
I have the following circuit to drive a logical output (the input is driven by an MCU):
The issue I have is that because of R4, when I want to draw a few mA from the output, the voltage drops. Right ...
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Identification of bipolar transistors on die (pnp or npn?)
is it possible to tell from this photograph whether the transistors are npn or pnp? And if so, what is the line of reasoning? How to sort that out?
This photo I took is from a Sharp GP1FAV51RK0F ...
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Calculating the gain of a specific transistor amplifier circuit
NOTE: There is an error in the drawing above — C1 should be connected to the emitter, not the collector.
Hi Electronics SE, hope this is the right place to ask this, if not I'll gladly take it ...
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Bipolar signal used in differential ADC
I'm trying to find a way to convert a bipolar signal from a load cell (Futek) to an input for a differential ADC on a TIVA microcontroller(TI TM4C123GH6PM). The load cell's amplifier outputs a bipolar ...
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Why do bipolar electrolytic capacitors have a long and short lead?
Ok maybe not all, but the Nichicon UES series of bipolar "audio-grade" electrolytic through-hole caps have a short lead and a long lead..
Why?
The datasheet has nothing to say about it.
This ...
user156429
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Orientation of "bipolar" capacitors on PCB
I've come across a video on a popular and well-respected electronics channel on Youtube where they say that even bipolar capacitors have a preferred orientation in a circuit that minimizes hum and ...
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What are the advantages of CMOS operational amplifiers vs bipolar in the same class?
Is there something else than Rail-to-Rail output and possibly lower power consumption for low frequency applications? Or Rail-to-Rail is the main one?
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Question about the role of specific element in a circuit (H Bridge)
I am currently studying different ways to design an H - Bridge and came across this circuit. I have a good idea how the bridge works except for the two transistors on the bottom that I have red ...
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Amplification equation for AC coupled Common Emitter stages
Do anyone can tell me how to get amplification equation for this circuit of coupled common emitter amplifier?
simulate this circuit – Schematic created using CircuitLab
Edit 1
Equation for ...
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How do I add a bipolar stepper motor to this circuit? [closed]
I have just started electronics at school and cannot find any tutorials on how to do this. I am creating a circuit that when the light intensity increases a bipolar stepper motor will step clockwise ...
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H bridge design for bipolar motor
I'm working on a dual H bridge for a bipolar stepper motor. I found these two designs. I would like to know which design would you guys recommend and why? and if there is any component that might be ...
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