Transistor? Answered

I am constructing the flyback driver found on the power labs website and cant get a 2N3055 transistor quite yet. I do, however, have a bag of transistors i pulled out of CRT monitors. I was wondering if one would be a good substitute for the 2N3055 for driving a new flyback, the number is C4916, the base-collector voltage is 1500 V and the Collector current is 7 Amp

Asked by budhaztm 6 years ago  |  last reply 5 years ago


transistor substitute?

Can i use bd 139 instead of bc 547

Asked by jumper1111 6 years ago  |  last reply 6 years ago


Choosing a Transistor ? Answered

Hello All.. I wan't to power up a 10A (12v)  loads with a Arduino .. What is best transistor for this job ? Also what is the resistor value to use between Arduino ? Thanks all..

Asked by EZELab 7 years ago  |  last reply 7 years ago


Transistor vocoder?

Hello, last night i was experimenting with my breadboard, and i came up with an idea, transistors have a supply voltage, which the small voltage controls pitch and volume. but i thought what if i had voice coming in to the supply voltage part(after being super amplified) and the keyboard comes in the control voltage side, would the keyboard not control pitch of voice, while voice modulates? thanks for your help.

Asked by ski4jesus 7 years ago  |  last reply 7 years ago


equivalent transistors? Answered

I need equivalent transistors for ac188 and ac187 and is bc548 equivalent to bc148 i couldent find equivalents on google

Asked by robot1398 7 years ago  |  last reply 4 years ago


Transistors in series

If I were to put transistors in series (and hook up there bases together through proper biasing resistors) would it increase the voltage capacbility of the circuit? I need a way of switching on and off about 1000 volts really fast. for example, would 2 750 volt transistors in series be able to handle 1500 volts or not? just a HV pic from my old, dead NST

Posted by guyfrom7up 10 years ago  |  last reply 10 years ago


transistors with leds?

New to led lights thought about using on fish tank the one post says to use resistors why is this necessary when using a transformer from alarm clock?

Asked by budman95 7 years ago  |  last reply 7 years ago


Substitute of Power Transistor

What is the substitute of 2N6292 power transistor? Please suggest a good substitute of 2N6292.It must be an NPN power transistor. Thank you.

Asked by SiamB1 2 years ago  |  last reply 2 years ago


AC187 Transistor Alternative???

Hi I was wondering if anyone knew of any Silicon or Germanium alternatives to the AC187 Transistor. Also is the BC548 or BC547 Silicon Transistor an alternative to the AC187 Germanium transistor?  Thanks in advance

Posted by Ikram1ali 3 years ago  |  last reply 3 years ago


Transistor H-bridges

Is it possible to make a transistor H-bridge with PNP transistors or can it only be done with NPN transistors.  As far as my knowledge( or lack thereof) of transistors goes, I think it would be possible, but it would require more than 4 transistors and it would be much more complex, however I could be entirely wrong.  Any input would be helpful, thanks.

Asked by jpenn 8 years ago  |  last reply 8 years ago


Transistor switching problem

I am having trouble using transistors to switch a some LEDs, I have 5 LEDs in parallel being switched by one transistor but each LED is indervidually switched by another transistor. I have given each LED its own resistor and the problem I am having is that when all LEDs are on each LED gets dimmer then if only one was on. I don't really understand why this is happening but I'm not 100% comfortable with transistors and I have probably done something stupid. I have attached a image of how I have wired it up with only two LEDs

Posted by camlv 9 years ago  |  last reply 9 years ago


Choosing a transistor (NPN)? Answered

Hey Guys, Recently I was ordering electrical components online and when I reached transistors I couldn't choose any. I was wondering that can I order any transistor or will it ave to be specific one? I need one for projects like wireless induction, laser tripwires etc. I would really appreciate it if you could help. Thanks in advance -Prickly Potato

Asked by The Prickly Potato 3 years ago  |  last reply 3 months ago


Transistor battery question

Hi, I want to know if I can hook up an 18v 3ah battery to a npn transistor with a max of 1a. Will the transistor only let through 1a or will it get burnt out? Thanks.

Asked by RyanF191 10 months ago  |  last reply 10 months ago


SS8550 D331 Transistor

Hi , Guys can you tell me if  2N2222 Transistor is equal ant to SS8550 . It's in an IR circuit . Thanks in advance :D

Posted by UsmanK14 2 years ago  |  last reply 1 year ago


Tip31 Transistor alternatives

I teach middle school science, and I'm helping a small group of keen students work on DIY projects.  One of the students wants to try this: https://www.instructables.com/id/Music-LED-Light-Box/ It calls for a Tip31 Transistor, which is proving difficult to find, at least in Canada.  The comments section suggests at one point that any NPN transistor will do. Can anyone confirm this?  Or can you suggest more readily available alternatives? Thanks!

Posted by dochockin 2 years ago  |  last reply 2 years ago


Transistor relay with NO and NC?

Does anyone know how to make a solid state relay with a NO contact and a NC?Does anyone have a schematic?Thanks.

Posted by thermoelectric 9 years ago  |  last reply 9 years ago


Passive amplifier with a transistor? Answered

It's possible to build a passive amplifier with a transistor? i have think about something that might work with a capacitor conecting the audio + to the transistor base. not sure if will do, and if it do i don,t know how much resistence is needed on the other end of the circuit. also i'm going to use 2 15 ohm speakers in series.

Asked by Misac-kun 6 years ago  |  last reply 6 years ago


Tube AND transistor amp? Answered

Asked by arhodes18 7 years ago  |  last reply 7 years ago


audio amplifier transistor? Answered

I pulled what looked like a voltage regulator from a PSU, i guess as it turns out its not? apparently its a audio aplifier transistor, but what would that be doing in a PSU? if its any use, it was near a fan connector on a small sub-board... markings are: UTC 2SD880 (2 small, undistinguishable letters)RKOB (or 0B) i believe this is the datasheet, correct me if im wrong. http://search.alkon.net/cgi-bin/pdf.pl?pdfname=utc/2SD880_TO220.pdf

Asked by zack247 7 years ago  |  last reply 7 years ago


Transistor Voltage Inverter

I am a newbie and was hoping someone could assist me. Given the following schematic which takes a voltage of 12v and considers it off and a voltage of 2 volts and considers it on can someone tell me what changes would need to take place regarding capacitors and resistors (if any) to account for 20v instead of 12v? Meaning that when 20v is considered off and 2v is considered on.

Posted by TimothyE2 3 years ago  |  last reply 3 years ago


what is alternative for BF194 transistor?

Asked by Prasanna KumarC1 1 year ago  |  last reply 1 year ago


what is equivalent of this transistor(BF494)? Answered

Asked by vikasgurlinka 2 years ago  |  last reply 2 years ago


npn transistor and impedance question? Answered

Hello , i have question about transistor .The picture below is a simple npn transistor booster .Can you give me the formula of gain and output impedance of this schematic please. Thanks! sorry for my bad English!

Asked by login721 6 years ago  |  last reply 6 years ago


Which transistor for ne555 output?

I have a simple circuit based on an ne555, the power supply is 15 volt provided by a robust ac adapter. On the pin 3 of the ne555 i need a max current of 4000mA. I was thinking to use a BD439 transistor, would be ok? And about the base resistor? Would be ok a 100k resistor or i need a different value? thanks a lot.

Asked by akopelumenuscu 3 years ago  |  last reply 3 years ago


RC circuit with a transistor and an LED Answered

Http://tronixstuff.files.wordpress.com/2010/06/pic23.jpg Could someone please explain how this circuit works? I understand that while the capacitor is charging, current flows to the base of transistor and so the LED lights, but I can't figure out the discharging. P.S. I assume that by building this circuit I'll get an LED blinking constantly?

Asked by MaracKoMarac 6 years ago  |  last reply 6 years ago


How to prevent transistor saturation?

I am trying to create my own audio amplifier. My problem was when i have large signal amplification the transistors becomes saturated, as a result the resulting signal is already clipped. This problem usually occurs when i use a transistor at CE configuration. Using CC configuration prevents this saturation problem but it also makes amplification very hard. When i use CC configuration one of the two transistors becomes "useless" because collector current becomes very low and based on further analysis it seems like only the last transistor is doing the job.

Asked by codestroy7 7 years ago  |  last reply 7 years ago


Resistor for NPN Transistor Base? Answered

Hey all, I need help identifying the value of the resistor I would need for the base of a 2n2222a transistor in this circuit. If you need any additional information, ask and ill try to answer asap. The resistance of the relay coil is 106 ohms and its rated for 6v but I operate it at 5v. The 3.3v is supplied by a step down circuit connected to the same power supply as the 5v used to operate the relay. If you can, please also list the steps you took to calculate the value of the resistor so that it can be useful for future use, I couldn't find a simple answer online. Ty,

Asked by SA-DIY 1 year ago  |  last reply 1 year ago


using a darling transistor as a switch?

Hi, i want to use my arduino to switch a set of high power LED's on and off (maybe PWM dimming later) but there are two things wrong. my set up is an arduino uno and a NPN TIP122 darlington transistor, the LED's should draw about 1.7A  max (on measurement its more like 0.2A average) even when the base of the transistor isn't connected to the arduino, the LEDs are still on.  when I set the base High using 5 volts from the arduino though a 1K resistor, the LED's are really dim  Ive looked though just about all of the tutorials online and I dont understand two things that are wrong with my really basic circuit. Im a serious beginner when it comes to electronics so any suggestions in layman terms would be appreciated  Thanks

Asked by bowlen199 4 years ago  |  last reply 4 years ago


what is the difference between a pn2222 transistor and a 2n2222?

They are both npn

Asked by death defyer 9 years ago  |  last reply 9 years ago


Transistor as switch with low leakage current

I don't really know much about transistors, alas, but I am looking to use a transistor as a switch in a device where it's important to me to that the batteries (3xAAA) last about a year. This means that I want to minimize leakage current. I would like to use about 20 mA at 2.7V to control 0.5-1 A at 3.3V (I have 4.5V at my disposal, so I can handle a 1.2V drop through the transistor). The device is a water leak alarm which I assume uses almost no current except when it's alarming. Any suggestions on what to use?  A lot of people use TIP120s as switches, but I've also seen comments that indicate that they have an unpleasantly large leakage current. And I don't need the high voltage/current/amplification capabilities of the TIP120. Or should I just use a solid state or electromechanical relay?

Posted by arpruss 3 years ago  |  last reply 3 years ago


How a Transistor connected to 12v and out 4.7v !!!!!!? Answered

Hello All, I have a problem with a circuit i am building, I use a 2N2222 transistor to drive a Common Cathode big 7 Segment  with a 595 shift register.. I connected a 12v to Emitter, the collector out a 4.7 volts !! How is this possible ? could some one explain please ? Thanks all

Asked by EZELab 6 years ago  |  last reply 6 years ago


How to safely jump a transistor? Answered

So I want to default the fans in this Xbox 360 I'm fixing to run at a faster speed.  Some people just borrow 12 volts from someplace else on the board and wire it directly to the fans.  I'd like to avoid this, since A) it seems like kind of a hack job, and B) I'd like the fans to run somewhat less than full bore since it's noisy, maybe 7-9 volts.  I've seen some vague mentions of either jumping or grounding transistors to achieve this, but I don't really know that much about transistors to do it safely. This thread here says that by grounding Pin 1 of the transistor (which is on the far left I believe?) with a resistor, you can change the voltage of the fans safely.  So where should I ground to?  Or does that simply mean bridge Pin 1 and Pin 4 with a resistor?  This guy here just bridged the pin on the far right to the top pin (Pin 3 to Pin 4 I believe) with no resistors involved.  Would that method be better? And if so, how could I step down the voltage, just a simple resistor as well? Also, I've figured out that B, E, and C refer to Base, Emitter, and Collector.  But what does that really mean in terms of practical application?  And the BCP51 transistor that is used in the Xbox has two pins labelled as "C".  I'm confused.  Here's the datasheet for the BCP51 for reference. Anyways, any help is appreciated.

Asked by RelaxedSoup 7 years ago  |  last reply 7 years ago


How do I know if a transistor is a 2N4401 or a 2N3904, etc? Answered

Good day. I'm a newbie scavenger, and I scavenge parts since I don't have enough money to buy new parts. I want to know if the transistor i found is a 2N4401 or a 2N3904 or another? I can't find it in the Internet. One thing I know is that it's an NPN transistor. I also noticed some numbers on the flat side of the transistor. Does it help in determining the transistor? Thanks in advance to those who will answer. :D

Asked by CarlGemarino 4 years ago  |  last reply 1 year ago


what are the requirements for using a bd 140 transistor?do i need to use another transistor to drive it?

My friend said i need to use another transistor like bc 547 at bd 140 base why?

Asked by 02.anand.m 9 years ago  |  last reply 9 years ago


How to parallel 2n3055 transistors? Answered

I am working on an inverter that will be run off a car battery. It will use a ne556 timer to drive the 2n3055 transistors (50-60Hz) I will have in parallel leading to my centre tapped step up transformer which will be a modified microwave oven transformer. My car battery is a 12V 65Ah battery that I will intend to draw about 200Amps from, the car battery will only be run through the transistor and transformer part of the circuit, the driver I will run off a much lesser power source.  Altogether I will be using 50 2n3055 transistors, two groups of 25 for either side of the transformer this will have a potential of 2875 Watts. How can I parallel these transistors to balance them to avoid cascade failure?

Asked by The MadScientist 7 years ago  |  last reply 7 years ago


Help with simple transistor circuit.? Answered

I want the LED to turn on when it's dark. But  it remains on and taking out the LDR doesn't affect it. I couldn't post a picture but i made a replica in Fritzing EDIT: The transistor is 3904 NPN.

Asked by Hafiz Mohammad Shayan Tariq 6 years ago  |  last reply 3 years ago


Astable transistor component calculation Answered

Greeting AllI made a few astable and monostable circuits. The one in the attached picture gives me an output of about 1 second, but i need to know which RC components i need to make it give a mark space ratio of 6 seconds.I'd appreciate if i can get the answer along with the calculation and an explanation of how to do the calculation.Thanks in advance for any assistance.KRGK

Asked by GhengisKhan1981 11 months ago  |  last reply 11 months ago


what is the function of transistor? Answered

Asked by Pranjal Joshi 7 years ago  |  last reply 7 years ago


DIY Transistor?

Do you think it'd be possible to make a completely homemade transistor? Not a homemade transistor amp or anything, just the transistor. I know, you could just buy one for cents, but you can also just buy a lot of stuff that you can have fun making. What about turning a normal transistor into a phototransistor? Just sand the coating off the silicon?

Asked by LeviMan_2001 8 years ago  |  last reply 6 years ago


How do i know if a transistor is of PNP or NPN type?

I want to know how to recognize the type of transistor.

Asked by bishal 9 years ago  |  last reply 9 years ago


how to use multiple transistor to switch single device so that each transistor has less load and desnt get hot?

I want drive a motor 12v havn't measured current but their product is enough to burn transistor can't i add more than one switch(transistor) so that current through each transistor is less or voltage or something like that that doesnt burn any thing. 

Asked by Atul009 5 years ago  |  last reply 5 years ago


information required about "NEC D882 PNP-transistor"?

I need help and instructinos about "NEC D882 PNP-transistor" i want to use it in lamp ballast.. tell me the other equivelent transistor.... the maximum volt and current we can give to these transistors.... thanks

Asked by bilalinpk 9 years ago  |  last reply 9 years ago



Quick Transistor question?

I am using pnp transistors as switches. I finally got a working prototype!!!Anyway my prototype motor runs at .18A and the real motors I want to run are 3.3ACan these PNP's handle that?http://www.radioshack.com/product/index.jsp?productId=2062585And can you tell me how to figure that out so I'm not always asking simple questions?Thanks!

Posted by kendallickes 9 years ago  |  last reply 9 years ago


How to amplify signal to transistor.

I have created a circuit using the diagram found here: The only differences in my circuit are that I only have used one LED and one 3 volt coin battery. I want to install this circuit in my headphones with the L/R and Ground soldered to the terminals of the speakers. On testing the circuit, I found that the light is only clearly illuminated when the volume is set to max, otherwise, it is very faint. I want it to work at lower volumes. How do I amplify the signal going to this circuit without building a headphone amp? I only want to amplify the signal going to this circuit, not the headphones. Thanks in advance.

Asked by Vijster1 6 years ago  |  last reply 5 years ago


latch with timed variable reset using transistors

I made a 555 t flip flop and it works nice (i use it as a light switch in my room), but i would like to add another button, whet i pres it would turn the light on  for a time and then automatically off after some seconds to minute. can anyone help me?

Posted by bugijs123 7 years ago  |  last reply 7 years ago


How to make arduino control transistor? Answered

My Arduino Leonardo needs to control some existing hardware. I have a digital output going to a 470 ohm resistor, connected to the base of an S9014 transistor. The transistor is connected in parallel with the hardware's normal switch. When the arduino should be triggering the switch, it's not. Where did I go wrong?

Asked by 4lifenerdfighter 6 years ago  |  last reply 6 years ago


What does mpsa transistor mean?

I have a project that requires mpsa13 transistor but the local electronics shop only carries mpsa12 i don't know what is the difference between the two, what are some alternatives or do they have different names in different country. thanks in advance

Posted by MaxF5 3 years ago  |  last reply 3 years ago


Transistor touch switch with relay. Will this work?

Hi So, I'm new to electronics, but I'm really interested to learn. As you will see from the diagram below, i still have a lot to learn. Basically what i need to know is, will the diagram below work in practice. I tried it out without the relay and with a led and it works i.e. pos to one side of the transistor, relay to the middle of the transistor and led to the other side of the transistor with the other end of the led to neg. I'n the diagram, i tried to add a relay and replace the led with a solenoid. Will this circuit work?

Asked by GhengisKhan1981 1 year ago  |  last reply 1 year ago


Simple transistor oscillator required - suggestions? Answered

I'm after a simple transistor-based oscillator for the basis of a 1-octave organ. I want to use recycled bits, which I have a lot of, and I reckon someone knows what's good as opposed to going looking for something. Crude, basic, simple, nothing sophisticated. L

Asked by lemonie 8 years ago  |  last reply 8 years ago