Questions tagged [transistors]
A transistor is a semiconductor device that can amplify signals and switch power. The types that are used most are BJT (Bipolar Junction Transistor), UJT (Unijunction Transistor), and MOSFET (FET, for Field Effect Transistor).
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Level Shifter design. 0-10vdc to 0-24vdc using pnp transistor
I have 2n3906 transistor. I want 24vdc output when 0vdc and 0vdc output when 10vdc. I want to give this output to plc which has 2.5mA min current requirement for logic high. I have 24vdc rail ...
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Sizing an CMOS StrongArm Latch comparator on Virtuoso from scratch
I'm currently designing an CMOS comparator and I'm a little bit lost regarding sizing the transistors. I was taught to use the Id formula, but for that to work I need to have muCox, and I do not. Can'...
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Common base configuration
I have tried to implement this circuit of common base configuration but the power supply used in the lab is very confusing and I suspect it’s the reason why my readings aren’t turning out right (it’s ...
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Taylor expansion relationship with transistor conductivity [closed]
Write an equation that represents the base-emitter voltage change and the collector current change of a bipolar transistor, assuming that the base-emitter voltage has a DC component and an AC ...
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How dome lights can burn out the transistors of PCB? [closed]
Dome lights doesn't work and found out transistors of pcb are burned out. Why this happened?
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Transistor works with just base connected
Currently I am trying to self learn electronics. After the diode I moved to the transistor.
I understood the transistor as an “electronic” switch with no moving parts. When the base is connected, then ...
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How do I select and use a BJT in a simple LED circuit? [closed]
I am trying to understand how to use a transistor in a simple LED circuit.
The LED (blue) has a forward voltage of 3V, and I'd like to provide it with 19-20mA. VCC on the circuit is 3.3V. I was ...
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The condition of linear operation of the transistor Dipole in small signal mode
How small should the base-emitter voltage changes of the transistor be so that the relationship between the base-emitter voltage changes and the collector current changes can be considered linear?
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Diode and bipolar NPN transistors orientation not correct, says JLCPCB
JLCPCB is telling me 4 components are incorrect but when I look over it and the datasheet it all seems correct to me.
My original | JLCPCB corrected:
This is what my current board looks like:
My ...
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SR flip flip memory cell
simulate this circuit – Schematic created using CircuitLab
I implement following circuit as SR flip flop memory cell.
It seems that both PNP transistor are turned on, and MOSFET-N can not turn ...
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NPN Transistor Base Current Calculation from Beta, Vth, and Rth
In this answered question regarding a common emitter NPN Transistor....
NPN Transistor common emitter calculation
I am struggling to understand the section "Assuming Active Mode"
...
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whats the Rin and Rout values of this circuit? [closed]
whats the Rin and Rout values of this circuit?
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How to determine the collector current limiting resistors for the Darlington's pair of transistors?
How were the resistors in the circuit calculated?, I would like to come up with a similar circuit but for a 5VDC power supply, and I would like to resize the resistors as per my load requirement, my ...
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Am I using these MOSFETs correctly?
I am designing and testing a circuit that charges a capacitor to around 50V using a boost converter when 'ARM' is high, then discharges it through a solenoid when 'FIRE' is high. ARM and FIRE are ...
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Three stage amplifier with third transistor connected to emitter of second
My question is that for voltage gain, is it correct if I take voltage gain of each transistor and then multiplying, to get gain of whole circuit?
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Computations for Capacitors in a Class AB Power Amplifier
How do you compute the appropriate values for the input and output coupling capacitors (C1, C2, C3) in this design of a Class AB power amp circuit? Are there any formulas?
If the formula involves the ...
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Inconsistent resistance measurement in H-bridge
I have an H-bridge circuit that is meant to measure the voltage across the shunt (330 resistor) and load (pictured as 4700, but variable) to calculate the resistance of the load (I have added the 10k ...
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How can I calculate the current induced in the copper coil that is wrapped around a single phase of an 11kV, 2616A distribution line?
Aim: To develop an alert system for power outages in the distribution line, informing electricians of their occurrence.
Working Principal:
Fuse Monitoring: The Arduino measures the status of the power ...
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How to control unrelated circuit with a transistor?
I recently hit this issue that seems to be too complicated for google to find results for.
Is it possible to control a different circuit with a transistor from a separate circuit?
Below is a ...
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Astable Multivibrator Not Oscillating
I've been trying to get the Astable Multivibrator Circuit to work for a long time now, and I think I lack the knowledge to understand what's going on here.
The situation is as follows: I've checked ...
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Will the gate driver circuit of MOSFET work?
I have implemented this circuit in the hardware. The desired pulse output across 2 Ω is 28 V output, minimum 10 A output current with 100 kHz frequency and 10% duty cycle. The drain pulse is not ...
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Why NPN Transistor AND Gate not working?
I am trying to form an AND Gate using 2 NPN Transistors, But the led lights up when i turn on the right switch and the left switch doesn't make any change, Can Someone please point out the problem,
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Correct circuit design to light an LED
I'm wondering if anyone sees an issue with this circuit. Basically using a button to control the Output Enable (OE) signal to a 74HC245 running at 3.3V. When the button is not pressed, the OE is not ...
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How to make an LED light when motor stops running?
How can I make the LED light when the motor stops running (aka the output from the op amp (pencil drawn) is low and so the transistor base input is low)?
In this configuration. My LED lights when the ...
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Operating regions of BJT
My TB says in saturation mode, the base-emitter and collector-base junctions of BJT are forward biased and in cut-off mode both junctions are reverse biased.
But in this graph the saturation region ...
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12 VDC to 24 VDC conversion for PLC input high signal [duplicate]
I have Siemens S7-1200 PLC DC/DC/RLY. It takes 24 VDC inputs. One of my inputs to PLC is 12 VDC. I want an intermediate circuit that converts the 12 VDC to 24 VDC. Moreover, I have a 24 VDC source ...
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Transistor Driver - what is the purpose of Q2 on the included schematic?
I saw this schematic at the link below and I would like to know if there is any use in particular for Q2. Since the transistor Q2 is just, somehow, operating as a simple diode that is following the ...
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Help in recognizing a component
Dear friends
i have a problem recognizing this component whether it is dual diodes or tranasistor and to find it's datasheet, can I find any help.
It is found in an LED lamp with PIR
thanks
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IR emitter circuit not working
I am struggling with IR emitter circuit which should replace remote control for few devices. I designed some circuit and already made PCB which uses P-channel mosfets for 12V device control. As I am ...
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Relay array or transistor array
I do a lot of 2 colour 3D printing and usually manually change the colour. Just trying to think of a way to automate the process for minimal effort, and limited modifying of my 3D printer.
I want to ...
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Gate pulse is switching but drain pulse is not
The above circuit input is a pulsed signal of 5 Vpp, 100 kHz. The required output is 100 kHz, minimum 28 V, minimum 10 A, 10% duty cycle pulse.
The switched pulse is observed at the gate but I'm not ...
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Why does my flyback transformer simply refuse to work?
I've been trying to create a Kirlian setup like the one in a video by 'The Plasma Channel', and the flyback transformer for the power source just refuses to work.
I have a T1010A transformer, and I'm ...
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Is there any way to know how real discrete components are being connected to each other using logical gates?
Let's say we created some gates or something with VHDL. How can I convert that code into those diagrams that show how discrete components (such as transistors and resistors) are connected to each ...
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Problem with push pull output
Well, I'm working on an oscillator topology to excite a piezoelectric device that works at high voltages. For this I have a high frequency signal generation stage followed by a push pull amplifier to ...
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Can I convert 12 V DC to 24 V DC using a 2N2222A? [closed]
I have a circuit which generates a 12 V DC high pulse when a laser is detected. I want to convert this high pulse to 24 V DC to feed into a PLC input (Siemens S7-1200.) Can I do this using a 2N2222A?
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Is this transistor schematic of a CMOS layout correct? [closed]
Working through some problem sets on CMOS circuits right now, is the following circuit correct?
It seems eerily close to a 3 input NAND circuit, except that the top three transistors I’ve drawn are ...
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Why does the voltage at the source side change even though it has no connection to the drain on this NMOS?
I was playing around with transistors and stumbled upon something I dont understand. I have the following circuit below:
Where the NMOS used has a threshold voltage of 5V. This means there will be no ...
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Difference between IGBT and FET+BJT
What are the practical differences between a true IGBT and a combination of FET and BJT, apart from a more efficient production and packaging? Can I obtain a device of comparable qualities to IGBT if ...
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The input to the gate of an N-channel MOSFET is a pulsed signal but I am getting a ramp signal
I am trying to generate an output voltage of minimum 30V and maximum 50V, current of minimum 10A for a load of 2-10ohms using a MOSFET.
I am connecting an NPN transistor's collector to the gate of the ...
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Alternative way to control a DC motor with an ATMega328P and external power [duplicate]
I am designing a PCB to control a DC Motor's direction with an ATMega328P microcontroller. The output isn't enough for the DC motor so I used a TIP120 but now I can't control the way the motor is ...
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Solving for values in an NPN bipolar transistor circuit
simulate this circuit – Schematic created using CircuitLab
I am trying to learn how to apply bipolar transistors in circuit but I cannot figure out how the textbook solved this one.
The book ...
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Tri-state buffer, why is it called high-impedance?
I found this picture of a tri-state buffer:
When the enable signal is 0, the output is disconnected from the voltage sources. But why is this called high-impedance? From what I understand impedance ...
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Relay control using ESP32 via a transistor
I have an ESP32 powered by a DC 5V 1A power supply. I want to control a Honga HF32FV-G relay using the ESP32 via a J3Y S8050 transistor.
I have connected everything and it works as expected, but I ...
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CMOS Inverter Transistor Sizing Wording
"Assume that both the gate lengths as well as W_n for the 180 nm technology in the table can have dimensions down to 180 nm."
I'm simply wondering here what they're referring to with the &...
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BJT 2 Stage Amplifier with Global NFB
I am a designing a transistor amplifier that will have a gain of 100-130 and output-swing of 6Vpk-pk, and frequency range of 1kHz-10kHz.
I am at lost how in the simulation my circuit work with the ...
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NPN Transistor Circuit Diagram
I have npn transistor circuit and want to change the input from 48V to 12V. My question is can i used same circuit digram using same npn transistor (S8050) for input 12V by changing the R1 and R2 ...
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How much gain I am getting and with the 2 stage transistor amplifier attached with a Global NFB [duplicate]
This is just a direct manual solving directly subtituting values in a formula with disregard to temp etc.
Sorry for the incomplete information here are the goals of this:
"gain of 100≤Av≤130 and ...
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Transistors: P-Type/N-Type circuit with high-school electronics knowledge [closed]
I am studying about transistors, and I have only high school knowledge about circuits.
I don't understand this figure:
How is this circuit closed?
What is the little triangle?
How do 1.2V and the ...
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Is this transistor amplifier with low pass filter correct? How should I measure the gain and frequency range?
My goal is a gain of 100-130 and a frequency range of 1-10 kHz.
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Guide in designing circuit with Solenoid Valve 12VDC interfaced with Arduino Nano
I am not of an expert and just beginning in electronics, I have tried to design this circuit. The schematic is for the 12VDC-4.5W solenoid valve to act like a gate valve to pass and stop the flow of ...
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