Help with a voltage regulator for a DIY bench psu

Hello i have an atx that i would convert into a diy bench power supply but i just realize that it was just 12v and my thing work need more voltage range so i decided to use an old, but still working, Hp 30v ps. so i was looking for a way to regulated it easy, i found the lm2596 and i dont know if it would endure or use lineal regulator such the lm317. so, i need help for any inexpensive alternative or any schematics, or whatever let me step up/down the voltage. Thanks.

Posted by mario.negretemunoz 1 year ago

DIY 4-component Buck converter, no ICs, need help with maths

I'm building a bike light around a Seoul P4 LED and some re-purposed 18650 li-ion cells from a laptop battery. I'll need 700mA constant current and can comfortably fit 8 cells in my enclosure. I've done some reading and I should be able to build a Buck converter relatively easily, but I'm struggling to find any good guides to help me spec the components. I asked on Dave Jones's EEVBlog forums and all the replies recommended either Linear Regulators (wasteful) or something designed using Webbench, which only helps with circuits featuring ICs. As a buck should in theory only need a transistor, a diode, an incuctor and a capacitor I want to build it myself out of through-hole components. Can anyone help with some guides or tutorials on specifying these components please? My degree was Computer Science and I was definitely better at set theory and boolean algebra than anything involving formulae!

Posted by ederfel 6 years ago

Circuit Design for DC to DC Buck-Boost Converter

Sir, I am Anand from india, I will made a project based on bicycle. I have take 5 to 80v From my Bicycle pedals. Generator power is in AC 3-Phase. I want to made next step. in this I want to this 3-Phase AC 5 to 80V are constant At 48V DC. I put the 4 batteries in series. 12V 20Ah battery I use. I want to charge this batteries please help me. Thank you.

Posted by AnandC10 2 years ago

Which Boost/buck converter? LTC3780 vs LM2577S LM2596S

Hi, brought two boost buck converters to build a bench power supply from a atx psu.  Brought the LM version first as i have read previously that these are quite efficient, then seen the LTC one, so thought i might as well buy that as well.  Looks like the LTC board will be able to go down to lower voltages and appears to have a greater efficiency, quoted up too 98%, compared with the LM's at around 80%. Thou i understand that with adjustments changes efficncey.  LM2577S LM2596S;=STRK%3AMEBIDX%3AIT LTC3780;=STRK%3AMEBIDX%3AIT Which one do you think i should use? Regards

Posted by JonathanM221 1 year ago

Ultra low voltage buck converter

I want to step down voltage from a 1.2/1.5v battery to 0.05V. Any advice?

Posted by huzefa 9 years ago

Use of IC Buck-Boost drivers in automotive LED lighting projects

I've been contemplating the use of high power amber or yellow LEDs in a low cost automotive warning system (think tow truck).  However, car electrical systems are not set at 12v.  They can range from 9 to 19v with spikes up to 70v.  To protect the components I would need more than just a current limiting resister.  Under those conditions they would need a buck-boost driver.  Unfortunately I'm new to ICs/power LEDa and not sure where to start.  I was hoping someone would be able to help me out with further guidance.  I Thanks! -Mike

Posted by vanmankline 8 years ago

Buck Converter for Parallel LED's

So I am trying to make a gift for someone that will include about 100 LEDs. These LEDs have a forward voltage of 1.8-2.2 ( I am going with 2V) and a max continuous forward current of 30mA. The LEDs:;=item2a16538fe0 Now, I want to be able to plug this sign into a wall so I have purchased an AC to DC power adapter that plugs in into a standard 120V AC outlet and supplies 12V with 2A of current. Here it is: I know one way I could make this work is to have multiple series of 6 LEDs, as 6 LEDs in a series would then require 12V. However, it would make this project a LOT easier to have all the LEDs in a parallel circuit, so I can connect one whole side to the positive terminal and one whole side to the negative terminal. I wanted to know if I could do this: Plug the two wires (+ and -) going from the AC to DC adaptor into a Buck Converter set to 2V and wire it to all the LED's via one wire to a bus wire connected to all of the LEDs' negative terminals and same for the positive terminals.  The converter I was looking at:;=item4ad24add60 Also, if I place the switch in between the AC to DC power adapter and the buck converter, the converter would only be on when the LED's are on, right? Lastly, would all the LEDs have the same brightness? I know at 2V with 100 LEDs the output would need to be about 3A. Is it okay given that the power adapter supplies 2A but at a higher voltage? As in does the converter convert the electricity to a lower voltage but a higher current?

Posted by soulmouse 4 years ago

Laptop powerbank 12v to 20v and upto 5A output using 18650 batteries with USB 5v added

Hello ladies and gentlemen.  Im looking into buying a laptop powerbank charger for my Lenovo X1 carbon that charges at 20v 4.5A 90w fast charge with upto 80% charge in 1hr. But it will also charge at 65w and maybe 45w I've read. But this will not give me the full power of the processors and gpu etc. Unless I charge at 90w 4.53A  there are are some powerbank that are around £100-170 for sale but these don't give full 4.5A. Mainly around 2-3.5A so will maybe or maybe not charge she give me full power of the laptop   so I'm thinking about making me own using 18650 batteries. Good Samsung or LG 2500maH plus cells. Prob around 3000mah.  Im thinking I could either use a buck down or step up and use the batteries on series from 3S to 8S and then 3-4P to give me around 10000mah. I'm looking for the best efficient output so I'm not sure whether to use higher input or lower input to give me 20v.  Or or maybe I could go the inveter route using a 12-24v 150w inverter?? Efficiency is the main thing here. What is the best option do you think. Should I use 12v or 24v for max effecient conversion.  Ive searched the instructables for such devices but cannot seem to find anything like this. Or would I be better to buy one??? I would want to add USB and USB c also. Defo USB 2.0.  Could you you please help me choose and find the answers please?  I fancy the DIY route because I'm looking into solar and battery power storage and also boost my range wifi range through either ptp or directional attenna. These projects will come after the laptop powerbank.  Any my help would be appreciated a lot.  Kind regards.  Scott. 

Posted by ScottL190 1 year ago

How to earn a quick Buck!?!?!?!?!?!?

I having money trouble and i need to know how i can earn a quick buck?!?!?!?

Posted by killer7 10 years ago

Mobile phone wind generator

Hi at school, I am making a mobile phone generator. It's only GCSE so my apologies for my lack of knowledge. It is meant to be a "wind generator" but it can basically be a renewable generator via motion. So since I get to take it home afterwards I designed it to be a little record player where you turned the platter and it would change a phone. This is where I need some help. Would this 24v motor provide enough juice to charge a lithium ion battery (with a boost or buck converter [if needed to step down to an appropriate voltage] then a constant current protection circuit etc) the output 5v to charge your phone? Here is the motor:|pcrid|88056614883|pkw||pmt||prd|2483716&gclid;=CjwKEAiA4dPCBRCM4dqhlv2R1R8SJABom9pHi1B_sRuR-4nr15ce-EWd51aCsEfYqFBsUJioUXEpvRoC1unw_wcB Thanks! For non-British readers :  a GCSE is (in the UK except Scotland) a qualification in a specific subject typically taken by school students aged 14–16, at a level below A level.

Posted by MukymooD 1 year ago


Want a trampoline for five bucks? That is real doe.

Posted by Josehf Murchison 7 years ago

Mechanical Bucking Rodeo Bull

Hey everyone, does anyone have plans or know a website that explains how to make your own mechanical bucking bull? Doesn't have to be as complicated as a proper one, just something to have a bit of fun on, and not too expensive to make. Thanks!

Posted by tapdogs1 11 years ago

Supercapacitor Voltage Draw

If I am charging a super capacitor with buck converter, that is a 1 amp, 1-18 volt output, and the capacitor is rated for 2.5 volts, how do I stop the buck converter from feeding it more than 2.5 volts? When I attach the capacitor to my digital power supply, it starts charging, and the voltage slowly increase to be more than 2.5 volts, at which point I turn it off. I was wondering will it draw more than 2.5 volts from my buck converter? If so how do I stop it?

Posted by merlinj 2 years ago

36Vd.c. @ 8.3A Power Supply + Buck Converter

Hello Friends, I have a 36Vd.c. @ 8.3A Power Supply that I would like to convert into a Variable Bench Power Supply. After researching the topic, I have decided on choosing a Buck Converter as opposed to a Linear Regulator.  Shopping around online, I stumbled upon the LM2596 Converter:;=item462bb7a8a5                      Any thoughts and or suggestions? Beyond that, I do have a general question... I've read on a few power supply instructables that it's recommended that all rails be used (for example all yellow/12v cables) to insure a more steady current. Now being that the max output of the above mentioned power supply is 8.3A and (please correct me if I'm wrong) according to the supplied spec sheets, power is coming from 3 rails, would it be safe to assume it not necessary to feed all rails into a buck converter since its output is only 2A? Please put me in my place...

Posted by davidkiyan 3 years ago


I want to build a robot that will cost a max of 300 bucks. Any ideas?

Posted by sci4me 9 years ago

My New Knex Arsonal

I just bought this set off ebay for 50 bucks... do you think it was worth it? post pics of yours too

Posted by iKill 11 years ago

Astrosyn Stepper Motors

I have 2 Astrosyn Stepper Motors that I bought and ended up not using. I was going to build a small cnc machine first but decided to go bigger with the first on I built. So i bought bigger steppers for my application. I bought them for 20 bucks each and now I am selling them for 20 bucks plus shipping for both. I would like to use paypal for any transactions. Thanks for looking.

Posted by r1dd1ck913 5 years ago

winterize a camper/motorhome

We are tired of spending $85 bucks to have someone winterize our camper.  Do you need to blow the lines out with air? how much antifreez and were

Posted by geohsnider 8 years ago

dc-dc Buck vs boost efficiency

Hi guys. When you  use solar panels and have gadgets with different voltage requirements  that you want to power up. I need atleast  2 different outputs, 5v and 12v  ,   so which is most efficient ,  12/15v panels that you  regulate to 5v , or  5v panels boosted  to 12v? is there any general advantage in either case and i,m talking about using  cheap ebay switch regulators / boost converters,  not anything expensive hi tech. regards

Posted by kristerh 4 years ago



Posted by DIRTYSHOTZZ 11 years ago

Uni-polor Stepper Motors

OK so now I have some Unipolor stepper motors for sell. 20 bucks plus shipping takes all 3. Thanks for looking.

Posted by r1dd1ck913 5 years ago

Can Some Help Me

I Have a linksys usb ethernet port. And a wii. i dont wanna spend 40 bucks on that usb thing or nintendo wifi usb,so i was wondering if i could make this work with it?

Posted by nameless 11 years ago


So I have this old Roomba that I got for 25 bucks. I figured I could just use it for parts but then I saw all the neat things you can do with an irobot create. Is there anything I can do with this one?

Posted by kfoster10 7 years ago

Switch mode power supplys

I am looking into different methods of power supply's when I found out about switch mode power supply's. These are the type of supply's that you have in your phone charger (or at least i believe so). The type of supply I need, is something that can supply a voltage of 2.5 volts @ 70 amps, and plugs right into the wall. To do this, I would use whats called a buck converter (because it lowers the voltage). So I was looking on amazon for things that would work for me, and I found nothing anywhere. so I decided to lower my expectations, and just look for any buck converter that would work with a input of 120 volts dc from the wall, after it was rectified, and filtered, and I could find nothing. Then I tried looking into building my own power supply, given a switch ic, which I looked for, and still found nothing, that could handle an input of 120 volts. What I was wondering, was how come basically every single thing powered by the wall outlet is powered by these, if none of them can handle an input of 120 volts?  And how do I find one that can. Also, how would I create my power source that can step down the main wall outlet power to 2.5 volts @ over 30 amps at least? Also, why is it that I could not find any switch ic that could handle 120 volts, if every phone charger has one that can? Do they not sell them to the public? Why is it that I could not find a Built buck converter on amazon that could handle an input of 120 volts? Could I modify a 30 volt one to work with 120 volts, or put something between the filtered dc wall current and the buck converter to do this? Thanks for the help, it is really appreciated.

Posted by merlinj 2 years ago


What do you think I should do? I think I spooked a monster buck off my property. (A 12 point) I have been keeping my eye on him during the off season but now he has disappeared.

Posted by Pat Sowers 10 years ago

I need a 18 Ohm resistor

Does any one have a 18 Ohm resistor that they could stick in an envelope and send to me because eighteen bucks is a little steep for A resistor. oh ,and radioshack doesn't carry them either :( ~Matt

Posted by iman 9 years ago

fiber reinforced concrete $$$

Online i can see that a 60 lb bag from quickcrete is about $5. ok. easy.   Shipping----$20 to----$50----- ouch. so .   where to find it?      gotta be someplace that has 1000s of lbs of it on the shelf, and sells it at 5 or 10 bucks.

Posted by Toga_Dan 4 years ago

cheap mythbusters

Does anyone know where to get all of the mythbusters episodes at a resonable price like: Season 1 part 1 Season 1 part 2 (is there a second season!?!) season 3 season 4 to buy all of them off of discovery it's 200 bucks!

Posted by guyfrom7up 10 years ago

Help me spend my money

I got $75 in Lowes gift cards and am having trouble spending it. What tools/materials should I buy to get the most bang for my buck? There are so many things I want I just cannot decide.

Posted by ehudwill 5 years ago

D.I.Y.: How To Build A Fully Automatic Cat Door?

Paying over $300 for one, is just too much. plus 40 bucks for each collars. Do anyone know How To build a Fully Automatic Cat Door?

Posted by marquita188 7 years ago

CyberPunk goggles idea.... cheaper altern.

Okkkkk so i was wondering in these type of goggles could be made and be made a little cheaper, there 99 bucks from and i was thinking why don't people on instructables find premade material instead of aluminum roundstock... whatever, so is anyone interested..?

Posted by Silverpoint 9 years ago

Steampunk USB Memory

Meticulously crafted from hand-polished brass and copper, the USB drive reminds me of something out of the art deco neo-future of Buck Rogers - or perhaps more apropos - Flash Gordon.If you want to know how to make it yourself, learn to read russian and go HERE

Posted by laminterious 10 years ago

Dumpster Pools Invade Brooklyn

Over in Brooklyn, some overheated and dedicated folks have turned some dumpsters into pools for their very own urban pool party. Not too shabby for a budget of a few thousand bucks. I wonder if they can connect them together to get a proper bit of space to swim in.via Treehugger

Posted by fungus amungus 9 years ago

Best Poster

Me and my brother are buying posters for our basement, and we want to know what poster is the best. We already have Scarface, Godfather, Indiana Jones, Batman: The Dark Knight. So if you have a favorite post it. (We would buy Saving Private Ryan, but it cost 20-30 bucks. Thanks

Posted by Thornburg 10 years ago

Cheap Power Conditioning Unit (PCU)

In the video released by the windbelt creator, he mentions that his PCU only costs about a quarter. I dont know if that is his mass produced price, or his off the shelf price, but does anyone have any ideas about how to make a PCU for say, under a buck?

Posted by fafnir665 10 years ago

New Jig Saw

I just went out and bought the Craftsman Evolv Corded Jig Saw, I have yet to test it but from what reviews said its a great little tool. I got it at sears for 30 bucks. Any tips or suggestions for using it as its my first jig saw. Thanks, Clemsonguy1125

Posted by imthatguy1125 8 years ago

guess-the-joke's-punchline contest

EDIT: THE CONTEST HAS CLOSED!the winners:blue ribbon: GorillazmikoHonorable mention: Dsman195267the joke:A man walks into a fireworks store and asks: "Can I have a bang for a buck?"the joke with honorable mention:a man walks into a fireworks store and says: "it's dark in here, can I have a match?"

Posted by DJ Radio 10 years ago

Need help in soundproofing a small card shuffler

I don't have any pictures of it as of now, but I was wondering if anyone might have some suggestions in what to use to soundproof a cheap little plastic card shuffler I bought yesterday for a couple bucks. I'm not sure what kinds of material I'd need, any suggestions?

Posted by dotdarkcloud 10 years ago

Can't Download PDF's!

I just upgraded to a 2-year Pro Membership. In Safari, when I click Download PDF on somebody's Instructable, it first looks like it's going to download, but nothing really happens! All I get is a blank dark gray window on the new tab that appears. What's going on? I just paid 40 bucks and can't download anything.

Posted by swinget 5 years ago

test RJ45Cat5 to USB Female

I'm new to this forum. I need some instructions. I have an RJ45-cat5 male to USB female connector that I bought for 3 bucks. I've tried using it to connect my HP 1050 j410 USB printer to my Linksys WRT54GS (wireless) router so I can have a network printer. (The Desktop is directly wired to the cable modem and the to the router.) It doesn't work, but I don't know if it's the connector itself, or that the printer will not communicate with the router, directly. Is there a way to test the connector with another piece of hardware to determine whether the connector is actually any good? BTW.. I can't determine from HP, whether the 1050 j410 USB printer can become a network printer. Should I just go buy a USB print server for 20 bucks, or whatever? I'm using an Ubuntu 10.04 LTS Desktop with AMD-64 processor. Thanks to you for the best advice. Shobuz99

Posted by shobuz99 6 years ago

get some money

I need some cash for something i found im to young for a job well a real job and i was wondering if you had any ideas? i dont want to like have a big hassle like going to nyc im in north smithefield. i need like 60$ for what i want. so i want a quick buck any ideas?

Posted by blue72 10 years ago

airsoft rpg/giant shotugn

Ok i finaly made a rpg for airsoft (usues my home made greandes) i might posted it up (dont have pic yet) and im gonna paint it but i need to change the presure system but i dont want to spend over 20 bucks per gun so im just wonering any other presure system?

Posted by gotja 11 years ago

Maybe Found Cheap EL Wire?

Hey,  I was doing a quick search on ebay and found this. Its cheap el wire. The best part is its orange,(Clemson Stuff). Its about 10 bucks including shipping.;=110416611409&Category;=71537&_trkparms=algo%3DLVI%26its%3DI%26otn%3D1 Is there any problem with this stuff. 

Posted by imthatguy1125 8 years ago

Cruise Ship 3d print

I recently went on the Disney Cruise and I thought it would be nice if I got a small model of the ship for my mom.  Turns out the model costs 50 bucks and I don't know how to design a 3d print.  Can somebody please post an instructable on how to make this ship and I will help with any details needed.  Thanks!

Posted by DoctorDv 6 years ago

Reinforced Anti-theft Backpack Straps

Hey guys, I'd really like a cutproof backpack without spending big bucks on it. Can anyone take a regular (aka cheap) backpack and run some steel cable through the straps without making it uncomfortable to wear? Should the cable extend beyond the straps into the fabric of the bag itself? Thanks in advance!

Posted by rwilliams8 3 years ago

self tying shoelace

Ok i know im gonna get alot of crap cause people hate it when i ask them this but the self tying shoelace i dont really feel like spending 20 bucks 4 that and ive been doin magic 4 awhile like 3 years and i just wanna know how to do it if you dont feel like syin it you can emial me at thanks

Posted by pyrokid648 11 years ago

Half broken monitor

I recently bought a 19 inch LCD monitor for 40 bucks (used). It works perfectly for about half an hour (i havn't timed it) and then the screen just goes blank. If i turn it off and then back on it works for a couple of seconds then it turns back off. If I let it be for a while (like an hour or just when I'm not using my computer) it works fine for another half hour. Is this an overheating problem or what is going on?

Posted by guyfrom7up 10 years ago

Mac OSX Leopard 10.5.1 - $75

I have here Mac OSX 10.5.1 (Leopard) still in the box, unused and for sale. This retails from the apple store for about 130.00, but I'm making room in my studio and I would like for it to find a new home! 75 bucks or best offer and it's yours. Serious offers only.

Posted by InvaderDig 9 years ago

3D Modeling Program?

I have some ideas for a project I want to build, but I'd let to sketch it out in 3D form and create a model. Are there programs that can do this? I'd prefer free ones, but I guess I can shell out a few bucks if needed. I basically just need somewhere to put my thoughts into a 3D design so I can view what I'm actually building.

Posted by freethetech 7 years ago

Your favorite dessert...Question

I have been ordered to come up with a new dessert for our menu at work and need some ideas. Keep in mind I have some VERY high quality vanilla. If your idea gets accepted by my boss you'll get ten or fifteen bucks via paypal. IT DOSEN'T HAVE TO BE A RECIPE, JUST AN IDEA. I will of course make an instructable of the item, and possibly some of the others.

Posted by adrewmc 11 years ago