Questions tagged [transistors]

The transistor is a semiconductor device that can amplify signals and switch power. Most used types are bipolar (BJT, for Bipolar Junction Transistor), UJT (Unijunction transistor) and MOSFET (FET, for Field Effect Transistor)

Filter by
Sorted by
Tagged with
1
vote
0answers
27 views

Using LEDs as light sensor - how to level shift 0.2 V logic up to 3.3V threshold

I have a reel of punched paper tape (https://commons.wikimedia.org/wiki/File:PaperTapes-5and8Hole.jpg) and I would like to design a simple optical circuit that can read the binary values from it using ...
0
votes
2answers
90 views

How much energy does a transistor use? Is it worth building a NOT circuit for a relay?

I'm a super beginner, but I've developed a circuit that appears to work. My question is if there is a better way to do it. I have two power supplies. The primary supply will power a load. When the ...
1
vote
0answers
36 views

How does one increase Vds in Transistors technically speaking?

I tried to google my question but I found no answer. Obviously the voltage at the drain is increased. But I'm actually interested how this solution is technically implemented.
0
votes
0answers
32 views

LED Controller Circuit Design with BJT

https://www.circuitlab.com/circuit/mthven79a2m6/led-controller/ I designed a LED controller to turn the led on/off. What do u think about my design?
0
votes
2answers
63 views

How are transistors on processor chips designed to withstand high operating temperatures?

The process for transistors grow smaller every few years, and operating temperatures reach around 100 degree Celsius. This makes one wonder as to how these tiny designs are able to hold up within ...
0
votes
1answer
45 views

Encode and decode SPDT switch over single wire

I'm trying to devise a way to connect a device to a SPDT switch using only one wire. Specifically, I want to connect a wall switch to some kind of smart home thingy, and I only have a single switching ...
0
votes
2answers
55 views

Voltage regulator circuit increasing voltage when I connect a lower impedance load

I found this topology for a voltage regulator using a LM 317 and a "current booster" PNP transistor: So, I tested this same topology with a little change: I used a TIP36C for the transistor ...
25
votes
3answers
9k views

Can you make a CPU out of electronic components drawn by hand on paper?

I explored a lot of literature about paper-based electronics recently, and one particular paper caught my interest: “Handwritten Oxide Electronics on Paper” (DOI: 10.1002/admt.201700009) by Elvira ...
0
votes
1answer
31 views

EE-SX1140 datasheet confusion

In the datasheet it is said that the collector current shall not surpass 20mA. Then there is VCC = 5 V, RL = 100 Ω, IL = 5 mA which should be with a voltage drop from collector to emitter of 0.1V -&...
1
vote
0answers
51 views

That is the value of Ri, Ro, Voltage amplification

Can someone explain what is happening in this circuit please? I am asked to determine the amplification Au = uo/ui
2
votes
1answer
99 views

Is there constant current flow in this circuit?

I am studying basic circuits, and have a very elementary question. When the photoresistor is exposed to light in the following circuit, is there a constant drain on the power supply? If this were used ...
2
votes
1answer
70 views

How to choose MOSFETS by using the datasheets infos?

I know all the theory behind the MOSFETs, how to calculate the Id current based on (W/L) and (Vgs-Vth) and etc. But, now that I need to project a real solution, I feel like all of this is kinda ...
1
vote
2answers
155 views

Can I use a ULN2003A IC as many transistor switches?

I want to make home automation using Arduino. Instead of relay modules, I prepare my own relay module using relays and transistor switches, in between the Arduino and relays. I want to make many ...
0
votes
1answer
111 views

Why did this very simple external power source switch circuit fry my ESP32/Arduino board?

So all i wanted to do was to control a 12V motor through a big spare transistor i had lying around. So i thought it may work and tested the transistor, and indeed it worked as a switch, when feeding a ...
0
votes
1answer
48 views

Capacitor selection drives voltage fluctuation from TLV700 LDO

I am building a wireless charger based on bq500212A (datasheet here) However, I have an issue with the LDO: It fluctuates the voltage by about 400mV in a wave. Blue is where I put my oscilloscope ...
0
votes
1answer
52 views

designing an amplifier with specific characteristics

I want to design a common emitter amplifier with these specifications: Av (gain) = 50 VCC = 5 V Rload = 0.25 kΩ Maximum symmetrical swing is considered but I can not get the collector and emitter ...
3
votes
1answer
110 views

How to create a circuit for this signal? Transistor?

today I measured a signal with my oszilloscope. Its a pressed button of my robotic vacuum cleaner. The strange thing for me is, that in idle mode (button not pressed) the signal level is at 3.3 volts. ...
1
vote
2answers
60 views

Why does this 8 step sequencer schematic need two resistors for each output pin?

I've found a schematic online for an 8 step sequencer and built it on a breadboard. Before I start experimenting with it and adding features, I'd like to find out if both 10k resistors are needed for ...
2
votes
3answers
99 views

Calculating MOSFET gate current at certain PWM frequency

I want to power the gate of an IRLB3034 MOSFET by a PWM output from an arduino. I know that the current required to charge the gate increases, the higher the switching frequency is. With 5v powering ...
4
votes
2answers
355 views

Choosing a power transistor with low dissipation

I need some advice about how to provide a DC voltage (between 0 and 24V, tunable) with high current (about 8A) to a motor. All the times I have done this, I have used a BJT Darlington pair like this ...
2
votes
1answer
107 views

TIP120 LED strip dimming with flickering problem + questions delay

I need some help with my Arduino program. Let me introduce the hardware and the goal. There is two white LED strip each one of them are controlled by TIP120 transistor. There is an potentiometer to ...
1
vote
3answers
98 views

Buildint series voltage regulator using transistor and zener diode

I am a new to the electrical engineering and currently trying to calculate the series voltage regulator for raspberry pi at maximum current draw. Raspberry Pi works at 5 volts and 2.5 amperes at ...
3
votes
2answers
193 views

Why are two transistors or one transistor and a resistor used for a NOT gate?

We use one n-type and one p-type MOS transistor for a NOT gate or one transistor and one resistor. Why can't we use one transistor only without a resistor?
3
votes
2answers
70 views

Converting Arduino Due 3.3V digital pin to 5V

I'm a real novice so please bear with my terminology I've got an Arduino Due which outputs 3.3V signal when digital pin is set to HIGH. I have a driver that needs to receive at least 5V from this ...
1
vote
2answers
272 views

What makes these LEDs blink?

In this video, you can see that the circuit produces two blinking LEDs. These are all the components to make it work. https://www.youtube.com/watch?v=BEGmT-9GIeE&feature=emb_logo&ab_channel=...
0
votes
0answers
54 views

Need help identifying transistor

This board is from a Rhyne UC7067RYE remote receiver for a ceiling fan/light fixture. I blew the transistor “Q6” (that’s the piece that broke off in pic 3). The fan circuit still works fine but the ...
0
votes
1answer
32 views

TTL Gates Power Dissipation Values

I am not finding any datasheets that provide clear information about the power dissipation of some gates of the 74LS series: 08, 02, 04, 00, 32 and 86. Can someone help?
1
vote
0answers
56 views

Electronic component name & value to be traced

https://en.wikipedia.org/wiki/Electronic_component What are the best ways to trace the electronic components value, name if the name & value are not able to be seen on the component itself ...
3
votes
1answer
45 views

Designing a non-inverting buck-boost converter [closed]

I am trying to design a non-inverting buck-boost converter using 4 switches (transistors). Note:The schematic is taken from Texas instruments. This can be summarized in the following points: 1- The ...
7
votes
4answers
1k views

How can I make an XOR gate with basic components?

I am a very beginner in logic gates and electronic etc. I am trying to make an XOR gate only with the help of some basic components like transistors in the NI Multisim simulator. I have use AND and ...
2
votes
1answer
42 views

How to control motor (1.5 V at about 0.5 A) with Particle Photon using optocouplers and transistors?

I’m trying to control a motor that runs at 1.5v at ~0.5A using a Particle Photon. I’m powering the Photon over USB (for now, at least) and the motor with a AA battery. I’ve tried designs based off ...
1
vote
0answers
55 views

Powering 5V Laser with Raspberry Pi 4 GPIO Pins

I am powering a 5V, 5mW laser that draws ~30mA (KY-008) with a GPIO on my Raspberry Pi 4. From my research, GPIO pins have a voltage output of 3.3V, so I'm not supposed to be doing this. Unfortunately,...
3
votes
4answers
93 views

Can I use some type of transistor i.e. BJT or MOSFET to act as normally closed relay?

I am designing a power bank which uses sustainable power generation methods for a school electronics project. It is based around the Arduino Nano. At the moment I am planing to charge an 18650 cell ...
0
votes
0answers
41 views

Arduino powering another curcuit

I'm trying to use my arduino to control my car's simple key fob which is controlled by a 3v battery and probably draws a very small current. I am controlling it with bluetooth from my phone. As a noob ...
0
votes
1answer
50 views

When working with logic gates and transistors, which is more important to pass through them for them to work, a high current or a high voltage?

So I was wondering, if, say, I'm getting a current from a transformer where the current is very low but the voltage is very high. And there's a diode to turn my circuit into a DC circuit. And I'm ...
0
votes
0answers
21 views

How Vds is calculated here? [duplicate]

simulate this circuit – Schematic created using CircuitLab There is also the resistance of the Mosfet which is equal to 0.25(Ohm) I just didn't know how to add it to the circuit. We're gonna ...
-1
votes
1answer
109 views

Is the way that VDS(max) is calculated correct? [closed]

simulate this circuit – Schematic created using CircuitLab There is also the resistance of the Mosfet which is equal to 0.25(Ohm) I just didn't know how to add it to the circuit. We're gonna ...
-2
votes
1answer
69 views

Which transistor ratings do I use when calculating something?

Let's say I want to calculate VBE for a transistor (for example). What do I use? VCE (Blocked) or VCE (Saturation) or VCE (max)? Let's say I want to calculate Ic/Ib, what do I use? Ic/Ib (blocked) or ...
1
vote
2answers
63 views

create delay before the next click on doorbell

I'm in a place where noisy people have the habit to click the doorbell many times ding ding ding, is there a way to make the doorbell, that when he clicks it, then he should wait 20 seconds for ...
0
votes
0answers
13 views

FET - unipolar transistor - Voltage-Divider, question about finding Idss and Id if no Vd given

If I am not given drain voltage how do I use the formula for Vp to get ID and IDSS current? So far in testing stuff I noticed that if the two resistors at the right side Rd=8k an Rs=7k are close in ...
0
votes
4answers
62 views

Details regarding PMOS and NMOS transistors used as gates

My lab instructor explained very briefly what transistors are and started by naming them NPN and PNP then switched to PMOS and NMOS and I (as well as my classmates) am very confused, I need someone to ...
0
votes
1answer
72 views

Is a resistor compulsory in a NOT gate made from an NPN transistor?

I am making a NOT gate using a BC337/BC547A transistor (tried both) and I have made this circuit (image shown below) using a simulator: This is working properly. However when I remove the resistor R1,...
2
votes
3answers
206 views

Why most particle accelerators used vacuum diodes instead of transistors?

HERMES III (High Energy Radiaton Megavolt Electron Source) at the Sandia at Sandia National Laboratories is the world's most powerful gamma ray generator. HERMES-III produces a highly energetic beam ...
1
vote
4answers
131 views

how to reduce turn-off delay time of PNP transistor

I am having tough time while driving PNP transistor with optocoupler to generate 1KHZ PWM signal. my circuit consists of micro controller which will generate 1KHZ pwm signal which will go to base of ...
0
votes
1answer
53 views

loop inductance of half bridge

i have a question for my class but i cannot answer it, any help to understand this question will be more than grateful. Why it is so important to minimize the commutation loop inductance of a half ...
2
votes
3answers
225 views

Does a transistor amplifier produce negative voltage?

So I've recently started electroncis and bought this course on udemy ("Electricity and electronics - Robotics by Ian Juby") and I'm slightly confused as to how the circuit that I've attached ...
1
vote
1answer
59 views

Isolation transformer = floating ac inverter [closed]

Its said that, in AC power system at power station neutral and ground connected together because of this reason we get electrical shock, as neutral and standing ground are same. Assume, if I power a ...
1
vote
3answers
74 views

Why is the PNP transistor used in this circuit?

Why are there PNP transistors here? from: https://www.youtube.com/watch?v=5_uYE4EWSKY&t=884s&ab_channel=SparkFunElectronics This shows a charge pump circuit that will be controlled via the ...
1
vote
1answer
45 views

DC residual current detection 24 volt DC

I am trying to make a DC residual circuit breaker( same as AC 10 mA RCCB) for 24 volt DC load. How can I sense and compare currents in positive and negative terminals and powering circuit off, a ...
2
votes
3answers
2k views

Why did my transistor break?

Let's consider this device I have built: It is essentially a power supply for a 24V DC motor. The power supply is switched on and off according to a proper control signal (which drives a relay) which ...