2N3055 Flyback driver

2N3055 Flyback driver really need resistor to work?

Question by james34602   |  last reply


2n3055 flyback driver? Answered

Is there a better transistor to use instead of the 2n3055 because those things break easily and are somewhat expensive. 

Question by Jimmy Proton   |  last reply


Can I use MJ3001 in place of 2n3055?

I want to build this inverter circuit, it uses 4 2n3055 transistors. Can I use 2 mj3001 transistors in place of that?

Question by Ankan Nayak   |  last reply


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?

Question by The MadScientist   |  last reply


2n3055 flyback transformer driver diagnosis. - Showing some sign of life Answered

Hello again instructables! Now I've finally gotten my circuit completed.  However, I can't seem to get it to work. I've tried to follow this : https://www.instructables.com/id/2n3055-flyback-transformer-driver-for-beginners/ I'm using the same transistor (2n3055) - I am however using an older flyback transformer. (see the pictures) I've also made this circuit without any success : https://www.instructables.com/id/Flyback-Driver-circuit/ (With another transistor than what he uses.)  I've also tried to 'test' the circuit using only a 1:1 transformer instead of the flyback to see if I got some kind of high pitched noise. (EDIT) After a tip from iceng I am now able to get a high pitched sound. But I am still not able to draw arcs. With my minimal knowledge, I've tried to search through the internet and this site for ways to troubleshoot it, and I've pretty much tried everything I can think of. Things I've replaced / tested - New standard wires  - Other wires for the windings - Less windings, more windings - Different transistors (Like I mentioned I'm currently trying with a 2n3055, I've got about 10 of them, so I've tried different ones.) - Different powersources : Batteries from 1.5v to 9v. - Switching around cables on the windings to try to get the right polarity - Checked the resistors. They work just fine according to my multimeter. - Checked the transistors. They work just fine according to the multimeter. - Checked for continuity where it make sense that there is, and that seemed to be correct. Hm, I think that's everything. If I've forgotten something essential, please let me know. Here are pictures of the different circuits I've tried to make, and two circuit diagrams. Edit: I've re-done my windings on the flyback, so they arn't quite as sloppy as they look on the picture. Edit : Added updates.

Question by Zaek   |  last reply


Can 2n3773 be swapped with 2n3055 as an output transistor?

Can I swap 2n3773 in this circuit: http://www.electronica-pt.com/circuitos/en/audio-amplifiers/44-audio-amplifier-90-100w-with-2n3773.html

Question by Davis Lambert   |  last reply


Lethal Ozone From Flyback Transformer? Answered

I am running a flyback transformer with a 2n3055 transistor which works perfectly giving me 2cm arcs but i get a weird smell ever time i run it for more than 10 sec i think its ozone is it lethal im using a 12v 2A power supply

Question by TheGreatResistor   |  last reply


Flyback Driver At 2KHZ? Answered

I want to drive a flyback i have laying around i have one of these modules: http://www.ebay.com/itm/221623454225?_trksid=p2060353.m2749.l2649&ssPageName;=STRK%3AMEBIDX%3AIT which can generate 2khz square wave and i want it to drive a mosfet irfp250n which will drive the flyback the problem is the flyback normally runs at 16-25khz and i am doubtful whether the 2khz will to enough to reach the resonance of the transformer Will it work?

Question by TheGreatResistor   |  last reply


Can a 2N3055 transistor be operated at voltages under 60v ? Answered

Can the minimum collector emiter sustaining voltage of a transistor be more than the power supply voltage or is that somthing else? For example can I run a transistor with a minimum collector emmiter sustaining voltage of 100 with a 12 volt power supply ? Thanks

Question by build a BOOM   |  last reply


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

Question by budhaztm   |  last reply


How to preset current regulation & short circuit protection ?

Found this awesome diyr Linear power supply design with voltage & current controlling- Foe more details--http://electronics-diy.com/power-supply-lm317-2n3055-0-28v-6-8a.php 1>Since it has no short circuit protection apart from the fuse,then how to preset current just like bench power supply by shorting the the leads ? 2>Without short circuit protection will the  2 two 2N3055 blow up ? 3>Please assist that what should be done for the modification.

Question by Dimitrioptimus   |  last reply


What's wrong with my circuit?

I have built this ne556 timer inverter with a few changes, R1 is now 470 ohm, R2 is now 3.3k ohm with a 10k pot, C1 is now a 470pF, and the Darlington transistors are now 2n3055s. I attached my multimeter to the circuit to measure frequency it should range from 150kHz to 450kHz with the 10k pot. While the pot was at zero (I think) the frequency was about 450kHz but when I started adjusting the pot the frequency went up to 1.1MHz, Why could this happening and how can I fix it? Also the 2n3055 on pin 9 was getting a lot hotter than the other despite their near exact conditions, why is this happening? I noticed when adjusting the pot that the frequency does drop to 360kHz then shoots up to 1.1MHz. Thanks!

Question by The MadScientist   |  last reply


How to pick out a transistor? What I should look for? Answered

I need a MOSFET transistor for a flyback transformer driver. Many guys said 2n3055 and I want another. How can I compare?or can you give me a list of transistors that I can use?

Question by theVader75   |  last reply


How to troubleshoot a flyback driver?

I've been kicking myself for months now trying to get my flybacks to operate. It seems that no matter what driver I build, or how carefully I assemble it, the only thing I get is silence. Even the simple 2n3055 driver does not work for me. I've checked the transistors, they appear to be fine. I have no idea what to do. Any ideas?

Question by iTixle   |  last reply


Will transistors in parallel hold up to a higher current? Answered

I'm trying to create a simple PWM speed controller.  The only problem is that this controller will need to be able to stand up to 100 amps (probably more, but let's just leave it at 100 for simplicity).  A typical 2n3055 transistor can stand up to 15 amps when properly cooled.  Will wiring 8 of these transistors in parallel be enough to stand the 100 amp current?

Question by aeronut01   |  last reply


Can't find the right pins on flyback transformer

 I used various guides to find the negative 0V pin but all outputs give the same values. What can I do to find it? It's one of those 'new' transformers. Also, my transformer to test the thing and use the multimeter is about 14VDC (and the readings when testing give about 16V :P). Should this work? As I live in Europe it should run on 240V. Something else regarding this: Do I really need to make a circuit driver for it or can I use the onboard waveform transformer thingy too? And, if I get this thing to work, could I make a 2N3055 driver but with a different transistor? (I have a IRF630N transistor, would that work? I've also got  C546B and C556B transistors....help!)

Question by snateraar   |  last reply


NPN BJT strange behavior? Answered

My linear power supply design has been using a PNP MJE2955 pass transistor wired to a 2N4401 as a complementary darlington configuration, but this was not an inherently stable design, and would oscillate when adding output smoothing capacitors, particularly MLCC types (with very low ESR). So I decided to try the far more common darlington arrangement, although I am not fond of the higher voltage drop. However the output was oscillating at approximately 3KHz with 1uF output capacitance, with NO input to darlington. I removed the 2N4401 so all I had left was just a 2N3055 transistor with the emitter connected to the output and the collector connected to a 20V supply. The output was ringing like crazy. The oscillation frequency could be changed by adding/removing output capacitance. Why is this happening? How should I go about stopping this oscillation? I originally had a 4.7k resistive load on the output but it did not significantly affect the output oscillation.

Question by -max-   |  last reply


Flyback Transformer assistance requested

I am having problems with the flyback transformer. For primer on where I am at, following the tutorial to locate the 0v pin the voltage was win the specified range. The flyback is from a old monitor that was monochrome but was still working.  No datasheet could be obtained. 10 pins if it matters. I am following the struct on using the single transistor driver.  Specifically a 2n3055 from radio shack. Lets pretend i wouldn't waste your time if i didn't triple quadruple check the wiring first. using 24v dc power supply schematic and page i based my driver on.   i am not getting the high pitched noise from the flyback. i have 5w 220 resistor and a 5w 27 resistor . my resistance ratio is important. correct? since there is a voltage divider there. i know its vague but can someone give me some direction to work out my problems

Topic by Chingasman   |  last reply


How to make a 1-1.5 volt voltage regulator at 15 amps?

Hi, I want to make a high current (15 or 16 amp) voltage regulator that outputs around 1 to 1.5 volts. Does anyone know how this could be done cheaply and easily? I've looked at the 15 amp schematic in the LM338 datasheet (http://www.ti.com/lit/ds/symlink/lm138.pdf  page 11), which uses 3 LM338s in parallel, but I'm pretty sure that takes the minimum output voltage to about 4v, way too much for me. I've looked at using 2n3055 transistor, but it seems like I'd need ridiculous heatsinking and probably fans to avoid thermalling out. I'm thinking of taking my power from an old PSU, 5 v rails, so not too much of a voltage drop, but it's hard to find stuff that can handle these kind of currents. I'm pretty much stumped right now, anyone got any ideas?

Topic by lolkent   |  last reply


analog circuit to mimic constant resistance load? Answered

I unfortunately do not have many big resistors that can dissipate lots of power, and would like to make a dummy load to test and parameterize batteries and power supplies. I want constant power, constant current, and constant resistance load, I do have lots of opamps and a few N and P channel enhancement mode MOSFETs as well as many 2N3055s and a couple MJE2955's. I think constant current is the easiest, since all I need to do is make a closed loop controller that will turn off the transistor as the current is exceeded, and turn it on as the current falls. Constant power might be more tricky, as I need a device that controls the bias on a transistor as a function of the product of the voltage and current, since P=IE or W=AV, and similarly, constant resistance, I need a thing that will divide voltage across the pass element by the current through it. I don't want to use a "slow" microcontroller for this, I like nice continuous analog control system, if that is possible.

Question by -max-   |  last reply


Why won't my flyback transformer work? Answered

I have a flyback transformer that I pulled out of an old tv that I didn't use, and I have been trying to hook it up to a driver to get some arcs. The driver I am using is a basic driver that utilizes a NPN 2n3055 transistor and a couple of resistors. I am powering it off a 12V drill battery. Additionally I have checked the transistor with a multimeter and it checks out ok. As far as the coils go, I have tried using coils that I located on the flyback, and I tried winding my own on the exposed ferrite core. What happens is I hook it up to the power source and nothing happens, I don't even hear the high pitched whining noise that is characteristic of the high frequency driver. I don't know what to do, I have tried a lot of stuff. I'm starting to think that maybe I'm having power issues? All the instructables that I have seen use sealed lead-acid batteries which produce more current than my drill battery which is at least 12 amps. How much current is needed? Any suggestions to get this working would be well appreciated. Thanks :)    -Andrew  

Question by jarheadwithm16   |  last reply


Joule robber - a better joule thief....

I had a look at some of our 'ibles for the famous Joule Thief circuit. While checking a few of the creations and checking their performance I noticed a massive flaw: Only LED's with very low power consumptions can be used. After some trial and error I was able to create a slightly modified version that not only lights white and blue 5mm LED's but also the very powerful Cree Led's - the later would require a suitable transistor to handle the load. I only used a salvaged BC556 transistor, so the LED starts working at around 0.5V, brightness is adjustable within certain limits to cater for the battery state. So instead of using a limited circuit that basically just doubles the input voltage with the focus of extreme low power consumption, my circuit is aimed on single cell battery lamps that might need more power. Using a very low voltage transistor with minimal losses would still provide a power source for batteries that are under 0.5V, while using a bigger transistor like Tip142 or 2N3055 and a modified transformer can drive a CFL lamp from two AA batteries, single cell if you don't mind a warm transistor. Biggest improvement however is that I don't use a toroid core, which makes winding so much easier :) I am not too good in drawing circuits and prefer the direct solder method for my prototypes but if there interest I would take the time to make some pics and draw a circuit for an Instructable. But with so many similar circuits already out there I wanted to get some feedback first.

Topic by Downunder35m   |  last reply


arduino - sound controlled rgb leds

Hey guys,i am modding my basement and i am using the following ible:https://www.instructables.com/id/LED-RGB-controller/there is a link at the bottom that takes you to a website:http://www.ledcontroller.de.vu/there is a schematic, and from other forums i am told that the irf9530 mofset has a rating of 12Athat means a total of 48A for the entire circuit as 12A for each channel r-g-b and the 4th UV, now is that safe for the entire circuit and is a pc power supply capable of delivering such amounts of current in a 12V format? i am alo looking for leds that go with this project and found this store in ebay:http://cgi.ebay.com/50X-New-5mm-Super-Bright-Blau-Blue-LED-Lamp-13-000mcd_W0QQitemZ260330237732QQihZ016QQcategoryZ31334QQtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262if you scroll down, what does the table tell about the leds? like the voltage and current required?i am a complete noob at electronics but i am good at soldering and am willing to learn...i have a habit but don't know if its good or bad but until i know how something fundamentally works i cannot blindly accept its function so on that note, if anybody is also willing to explain the workings of the circuit please do so, any insight is greatly appreciated...thankx for any help...****************************************ABOVE METHOD SCRAPPED****************************the above method is no longer possible since no one has the parts for the above schematic here in my city, so now i have resorted to arduino to save the day...my idea is to have audio going into the arduino and analyzed to out put a "visualizer" in R-G-B channels. this then goes to a transistor which controls three chains in parallel of 1 watt leds. each chain as five 1 watt leds in series. each led is [voltage coming soon] and 350mA ... now i haven't ordered any parts yet, and not even the arduino but will tomorrow and so i need to know if this setup is going to work and i have seen others do it like this fellow:http://www.youtube.com/watch?v=GhobBh30wTM&feature;=relatedthis is exactly what i want to do but at a bigger scale. i don't know what type of transistor i will use but i have a handfull of 2n3772 and 2n3055 and 2n188a on me... i know i am throwing out random components but i am still not giving up, even if it means missing newyears deadline...

Topic by Slisgrinder   |  last reply


Hello! I don't seem to be able to get power through my flyback transformer (or actually, I'm not sure what the power isnt going through.) I used copper wire for the primary windings (Do I HAVE to use magnet wire for this to work? - If so I understand what my problem is.) And slightly smaller red copper wire for the secondary windings. I am using this http://pdf1.alldatasheet.com/datasheet-pdf/view/16901/PHILIPS/BU2520DF.html transistor  But also have a few others I could use. Have tried another one, (can't recall the name at the moment, but had the exact same problem.) I have tried to switch the cables around etc like suggested in https://www.instructables.com/id/2n3055-flyback-transformer-driver-for-beginners/?ALLSTEPS Also, I am unable to hear any high pitched noise. I am currently using a 12v car battery. (And it has power on it, at least enough to run a rather big DC motor.) As you can see on the pictures, my ability to connect things neat and clean is non-existent. - And I do apologize about that. And the pictures are horrible, as I'm not quite sure what you might want pictures of. I'm not quite sure what else I can ask.. I have tried another source of power. And it has the exact same problem.  The flyback transformer is from a CRT PC monitor. Same with the transistor. I've also tried another transistor that I got from a PSU for a computer. and it still has the same problem.  I have checked the cables and I know that there can go current through them, tried it in another circut. I was also wondering if the resistance could be broken. At this moment I don't have a multimeter close by so I don't know how to test it.  I used copper wire for the primary windings (15 windings) And Red copper wire (If this has another name and my ignorance is shining through, I am sorry.) for the feedback windings (11 windings) Are the windings just completely wrong?  My feedback wire is slightly thinner than my primary wire as well. Check the comments for picture of circuit diagram and a look-a-like of my primary winding copper cable. And I hope I can get other replies than "Buy a multimeter you silly git!" - Yes. I will, eventually.  If required, I can upload the pictures to another host so you can view them in a much higher resolution. Edit : Added a few more hopefully helpful pictures, since the first ones were utter crap. Please let me know if there is anything else I need to get better pictures of.  Also, I removed the on / off button from the circuit now as one can see on the latest added pictures. Thanks for your attention. Zaek.

Question by Zaek   |  last reply


BJT vs MOSFET? Answered

-- background: In my perpetual pursuit for designing the best, cheapest, & best performing flyback (line transformer) driver, I've decided to try out some big BJTs, which appear to have higher voltage & current ratings @ considerably lower cost. In the past, I have tried MJE3055's, which work OK, and allow the generation of thin blue arcs from a 12V supply for a few minutes until the transistor dies due to high voltage kickback or overheating. The FDP33N25 gives good results but is somewhat unreliable at 24V. So I decided to give these alluring "PHE13009" 400V 12A rated NPN BJT's a try. However driving the transistor adequately seems to be the problem. (I didn't realize these transistors would require like 5A base current w/ only HFe of 2!) It seems like almost all the "good" driver schematics utilize large $$$ FETs or even IGBTs, but almost every CRT, plasma globe, and ballast (SMPS) I took apart seem to prefer high power BJTs probably due to this exact cost difference. I was only able to get simalar performance to my 33N25 MOSFET when I stuck an additional TIP120 in as an additional darlington stage, which worked very nicely (white hot arcs) for about 1 second, then it popped! :( Since the collectors are tied together they are all exposed to >200V transients, I am sure that's what killed it. I substituted that transistor for another PHE13009 to see what would happen and with a third driving stage (2N2222) I could get somewhat acceptable results but I know I can do better. >:) - My actual questions:  * The GDP of this transistor is 40MHz, seems fast to me. (certainly faster than the 2MHz GDP of the 2N3055 which works well in my slayer exciter.) and MOSFETs have significant gate charge. ECE2630 glossed over transistors mentioning BJTs are faster, (small signal ones, anyway :P ) and some internet sources agree, but I am finding lots of sources saying the opposite! What's the deal? Which one "faster?"  * How to traditional BJTs compare to IBGTs? Which are faster/better? The datasheet for this transistor explicitly mentions its use for "high frequency ballast and switch mode applications" which implies that it is well suited for my needs. It also includes a several inductor test circuits, but other than that the datasheet is pretty bare-bones.  I'm actually a little disappointed the HFe is so low (around 2-3) @ >10A. I may require more windings on my primary and a 48v supply. (not ideal) * I know I will dissipate a little more heat due to the base current, and something I didn't consider was heat dissipated in the resistor biasing/controlling the base. (like 12V at several amps just to drive the damn thing!!) so it is worth the cost benefit of $0.5? Is there a configuration I could use that makes driving the transistor easier?

Question by -max-   |  last reply