i need a power supply

I am making chlorate's in a cell. but i need to give it about 5 volts and 1-2 amps. how would i do this cheaply?

Posted by DELETED_DELETED_kruser495 10 years ago

What to do with free power supply?

I got this in the mail today from Allied (Free Sample) http://www.alliedelec.com/search/productdetail.aspx?SKU=9210079 SO...  what should I do with it?  Any thoughts?  

Posted by RicoSPD 8 years ago

12v 20-30a power supply

Good day yall, i want to make a simple power supply to power up car amplifier, i have a transformer the trans former and is working with the kbu 606 diode, what type of regulator would be best to use and how much would i need, and if you have a diagram of something simple that can be adjusted then that would be great, thank yow

Posted by WIZZIEDEE 6 years ago

ATX Power Supply Conversion

Hi Again, My question is when building an ATX power supply, Can you join the 12 volt leads with the 5 volts leads to make 17 volts? If not how can I get lets say 20 volts. I am going to use a DC to DC converter to make a variable power supply. I would like at least 20V in then I can adjust from 1.2 to 60 volts out. I use it now running directly off battery but would like to add it to the ATX build case. Thanks for any help again.

Posted by Shorty954 3 years ago

power supply voltage reduction 9v input to two 3v outputs

Hello all ! I'm new to instructables and I’ve found some cool and helpful information for my projects. I need a bit of help designing a power supply voltage reduction device. One that accepts 9v input and output into two 3v 5mA outputs. I want to replace the batteries in a/b Boss selector with a more reliable source of power.

Posted by testpartner 10 years ago

ATX power supply conversion

I know this is a long passed DIY. But while building a ATX Power supply I separated all the wires as stated. I then put the green and a black wire to a switch and added the 3 brown leads to the orange leads. When I plug in the unit the supply light comes on, but when I turn the green wire switch the main power LED goes out and no fan comes on. It acts like the switch is shutting the unit off.  Can anyone help. I am 60 years old and just getting into doing some bench work to pass the time. Thanks for any help.

Posted by Shorty954 3 years ago

Power supply help?

Hi- i have an ION electronic drum kit that i got from a friend, but i somehow managed to lose the power brick. It wants 9V AC & 850mA, which for the life of me i cannot find anywhere. So, does anyone know where i can find one, or if there is something else that might work? Thanks a lot.

Posted by Samster1214 10 years ago

48 volt power supply

Hello everyone. i am interested in building a power supply from 0-48 volts and able to push a good amount of amps. any one have a ruff idea on how to beable to adjust the voltage and not limit my current to 2 amps i would like to puch say 15-20 amps. i can build the rectifier i have a 600v i think 30 amp bridge rectifier. just not sure on how to do the adjusting without useing a regulator chip that only pushes a few amps. any help would be greatly appreciated.

Posted by omnacron 4 years ago

SMPS to Bench Supply - Help

Hi There, I want to make a bench supply using my old SMPS. I have seen many tutorials and I've some questions which I need assistance with. My SMPS says 12 V @ 25 A, 5 V @ 10 A and so on.. In tutorials I see people soldering all the same colored wires to one output 12V, 5V, 3.3V and so on. So, if we do that and I connect a 12V device that operates @ 2A or 3A  to the 12V ouput @ 25A in SMPS that we make, will it fry my device. If so, how do we control the current to supply 12V @ 2A only. I want to make a bench supply with below specifications. Can I do that? 1. I want 2 to 3 outputs each for 12V, 5V and 3V. 2. I want to regulate the current for each such socket mentioned in clause 1 to 1A, 2A, 3A and so on.. Is that possible? If so, how any instructions? Thanks, Avinash B

Posted by goudavinash_b 1 year ago

What would you do with five 5 v 75 amp power supplies?

I have these lying around and I know they are useful, but I'm just not sure how.

Posted by iculus 9 years ago

pls help about power suppy

Can anyone help me? pls give me some advice how to create 0-10volts and 3amps(fixed) output power supply... give me some tips and some schematic diagram... i need it badly in our project...

Posted by stanum887 8 years ago

Power supply

Last time I tried to do my own homemade project I failed utterly, I think mostly because I had no idea what anything was (if you saw my last topic on a distortion petal, you know what I'm talking about). I decided instead to buy a book (Tab Electronics Guide to Understanding Electricity and Electronics by G. Randy Slone) which has projects in it, the first one being a power supply. I haven't started building it yet (waiting until I get back to the city) but I've started looking up parts. The thing is, I can't find a 4400-uF 50-WVdc capacitor anywhere! So my question is, can I just put two 2200-uF 50-WVdc capacitors in parallel to do the job of one of the 4400's? That isn't my only question, just the first which I'll ask later in this thread. Thank you (PS: Has anyone had a problem with using Chrome and entering text into these fields? I had to switch to Firefox to get it to work)

Posted by gohuskies 9 years ago

Building 24 VDC using three 9 v dc battery

Hi , Any circuit that I can use three 9 vdc battery to get 24 VDc output less than 1.00 amp . The power would be used for demos powering sensor that can accept 12~24 VDC.

Posted by rganap 3 years ago

How do I transform a power supply to other voltage value?

Hi! I need a 9.0 V AC  1.0 A power supply but despite I have a lot of power supplies around, no one has this values. The most I have are 12 V DC I suppose there must be some method to lower or rise the voltage of a power supply to meet the required voltage. Also, the resulting power supply must be AC (I also have a 20V AC power supply if this is easier than converting from DC to AC) Please, tell me what do I have to do.

Posted by jedikalimero 7 years ago

OEM Power Supply

I have an unregulated power supply, with a bridge rectifier. I suspect that the rectifier is damaged. I measured the components and the voltage on the rectifier, every connection past that measures 0 volts. Shall I replace the 4 diodes?

Posted by knektek 8 years ago

Question about low voltage power supplies

I have several wall plug power supplies. The voltage on one says 12v 300ma but on my multimeter im getting 17 volts. Why is it 17v and not 12v?

Posted by Rob K 10 years ago

12v power supply using AA batteries help

Hello!  I would like to power my arduino using a 12v 1A power supply, can i achieve this by using 8 AA batteries? Or would that not give me 1 amp? The arduino only draws around 50mA i believe.  Thanks in advance!

Posted by lelegriccioli 4 years ago

Online supplies?

Hey guys, question for you guys. Im looking for a good online sotre for electronics parts. Ive looked at a few but it seems i can't find a store that has everything. LED's, resistors, tools, capacitors, etc. Plus the cheaper the better. Anyone have some ideas? EDIT: Can someone also suggest a good size of LED's for general building and work. Thanks

Posted by BraedenNaylor 9 years ago

power supply cooling

Normally I'm pretty good with electronics, but I need some help with this problem. I'm building a power supply for a cnc machine and I need help designing a circuit to power fans when it's over a certain temperature. Here's some things it needs: 1) 12 volts supply (easy with a transformer and filtering it) 2) power fans when it reaches a certain temperature. 3) still keeps the fans on even though the rest of the system is off. 4) after the system if off and it's down to temperature then the transformer turns off, to save electricity and to not make it hot after a long time. If possible can someone draw up a schematic? Thanks in advance!

Posted by guyfrom7up 10 years ago

Computer power supply $15

For sale is a Power Tronic switching power supply for a computer. One plug has been cut off I think it may have been for the power switch. The harnesses to the left have a second plug for a total of six plugs. The fan shroud is 3 3/16 high from the top of the supply its 1 1/2 high on the left and tapers to 1 on the end. Here are the ratings. Dc output Min Max +3.3v 0.3A 12A +5v 2.5A 18A +12v 0.2A 4.2A -5v 0A 0.5A -12v 0A 0.8A +5VSB 0A 0.7AI will include the power cord for free. $15

Posted by Zuma07 9 years ago

Can you run multiple mobos off one power supply??

I was wonder, as I have a whole box of assorted pentium 1's (although I still have to gather up the processors around here, I also have an old p2 sitting here somewhere). I only have a few power supplies, and really, getting more power supplies isn't a problem, but they can consume a bit of power all together. I was wondering how many motherboards it would be possible to power off say a 300 watt power supply? I was thinking of splicing some additional mobo power connectors in off other power supplies. I want to just run these all open and don't plan to use them for much more than giant hard drive controllers (4 hd's to a mobo isn't that bad, wouldn't take up much more space than 4 external usb drives).

Posted by Punkguyta 9 years ago

Direct connection of 5V from power supply to front USB

Hello, I need to charge some devices via USB, but my computer seems to give less than 500mA, so charge takes 12 hours... I have one unused front USB on my computer, and I would like to ask if it will be a good idea to solder the pins 1 and 4 of this connector, directly to a connector coming from the power supply to get 5V but without the limitation on current. Any comments will be appreciated. regards, Angel.

Posted by angel6700 8 years ago

How do cheap power-supplies work?

I was briefly entertaining the idea of making my own power supplies for some electronics projects.  Everything I see involves the basic two step process of: 1)  Use a transformer between the 110V mains to bring the voltage down to the level you want, 2)  Use circuitry to smooth out the current from AC to filtered DC.  However, when I went to price transformers, I quickly discovered that to buy a power transformer rated to hook into 110V AC, the transformer alone would always cost significantly more than the cost of buying a full ready-made power supply of similar output. You can't buy a transformer rated for 110V for under $20-30, but you can find thousands of cheap wall-warts (transformer plus AD/DC conversion circuitry, plus connectors)  for <<<$10.  Or, if you look at higher wattage units, you find similarly rated (for volts and amps) power transformers cost $30-100+ dollars more than full power supplies. How are these cheap power supplies made for the prices they are sold at?  What am I missing here?

Posted by SvdSinner 6 years ago

More patches?

According to my "you" page... Soon, you'll be able to buy or earn more [patches]. For now, wait until next month for your next batch of patches. Do we get a monthly supply, or does that text need changing?

Posted by Kiteman 8 years ago

Regulating a Spark

I need to build a unit capable of supplying a timed spark. At approx 1 sec intervals. The unit will need to be small/cheap to build and be able to supply current as to generate a timed spark across two electrodes via 240v power supply. The unit I am attempting to build is a flammable gas warning/ignition device. The purpose of it is to ignite the first immediate gas detected, as to avoid a larger detination later. The unit will be made of machined aluminum. It will consist of a vapour detector hooked to a fan unit, which inturn vents the gas to the ignition device. Thus igniting the gas. At the moment I am working on the ignition system, hence the question. Thanks for any help.

Posted by Lftndbt 9 years ago

Power supply cooling

I'm building a power supply for my cnc machine that gives off about 37volts at 8 amps, and 12 volts at 0.9 amps. All of the transformers are from radioshack (using 6 heavy duty, 25.2volts, 2 amps transformers, 4 in parallel giving off 25.2 vdc at 8 amps, and 2 12.6 volts in parallel. Together in series gives about 37 volts at 8 amps. using 1 25.2 volts 450mA transformer, center tapped) My case does not have enough room for proper cooling such as fans. My case is water tight though, should I fill it up with something like mineral oil to keep the transformers cool?

Posted by guyfrom7up 10 years ago

How about a teeny tiny power supply??

I've seen some pretty good power supply projects on here. Here's a challenge: Make a 5 to 12 volt power supply that can fit into a 1 cubic inch space, of any dimensions, i.e. 1"x 1" x 1" or 1/2" x 2" x 1", etc, including any enclosure. It must put out at least 300ma sustained and must have a fairly smooth voltage regulation for use with other electronics (of course). It must have clear schematics without the use of special programs to view, i.e. it shouldn't be in an eagle format or rather can be viewed with paint, or any of the other picture viewers. It must be powered from the mains and NOT use a microcontroller or any custom chips. The smaller it is, the better, and less than 1 cubic inch is excellent. I've seen real genius on here. Is this genius ready to try this?

Posted by Pazzerz 9 years ago

power supply to arduino

Actually i am trying to make a web connected robot after seing it from instruct table.com the wiring skeem which is shown in it is :- they are powering the arduino with a 9 volt battery from the connector and running the servos with the 4AA batteries so i also done the same thing but when i done it then an error starts comming while uploading the programe on the board so i contact the manufacturer of the board so he told me that your chip has got fried and if you further want to protect your chip so set the jumper before providing external power supply but on instruct table they directly have done all the wirings they does not have told of jumper and all. as i am really new to arduino i does not know how should i set the jumper.so please help me out..........

Posted by armaghan rehman 4 years ago

Need help powering two circuits on a single power supply

Hello, I need some help with a project I'm working on and hopefully someone has an answer. I'm building a white noise generator  and it consists of two circuits, the white noise generator and a amplifier. Now when I bread boarded these I had each circuit built on its own bread board powered by its own 9v battery supply, but I want to have both circuits powered by a single 9v power supply with a 5v voltage regulator. Now when I bread boarded the device it worked fine using two 9v batteries powering the individual circuits, but when I connect them to a single power supply the circuit starts oscillating instead of generating white noise.  I've tried all sorts of different ways of rewiring the circuit, but I can't get it to run on a single 9v source without it oscillating. I think it has something to do with the amplifier signal feeding back into the white noise circuit. What I can't figure out is why it works when powered by two separate power sources and not a single power source. Anyone have an idea of what's going on here? I could really use some advice.

Posted by nfortier 4 years ago

light bulb

Hi, i got a problem with the power supply of a light that i found in an old car. it is a 6V 55W  light, the thing is that i want to make it work with a battery made of several cellphone bateries but i don´t know really whats the  voltage and current that my recicled battery must have in order to turn on the light and survive. thanks for reading, and i hope  anyone can help me.

Posted by kvalero 6 years ago

Power supply/Adapter Question

Okay i've recently bpught an rc battery quick charger. the input on it just says 12-13.8v i do have a standard 110 to 12v @ 400mA Should the ma Matter? you can hook the battery up to a 12v battery in order to power it also. basicly i'm wanting to know if i could use my ac adaper to power it. Thanks in advance

Posted by Pie_eata 9 years ago

Needing Schematic for a High Amp Power Regulator

I have two transformers ( 430-7101A) that're wired together from a APC Battery Back-up that I'd like to turn into a high amp regulated power supply. I've been looking through the site and have seen very few options. I'm positave that (sorry for the pun) there's a shematic somewhere out there and would Love to get my hands on it. These are a very nice pair of transformers that I'd Hate to see go to waste. And help would be Great! TIA

Posted by your_dragon113 6 years ago

Noisy pot issues?

Hi, I've been experimenting with a variable output power supply. It takes 18V @ 2amps in from a wall adapter. It uses the LM2596 simple switcher as a regulator. My circuit is more or less the same as the test circuit from the datasheet (image attached). The only thing I've changed is that R1 is a 5k trimpot and R2 is a 50k 10-turn pot. The trimpot is so I can dial in the proper value for R1 and the other pot is to vary the output voltage. It works more or less as it should. The one issue I'm having is I think due to the inherent "noisiness" of potentiometers. When I turn the knob (sometimes it seems when I just touch it), the output voltage will "spike" up. It eventually falls back down to where it should be and stays steady, but it seems to spike everytime I adjust it. Does this indicate a bad pot? Or is there some additional filtering circuitry I can put to avoid these spikes or ripples? Would another L-C filter help? Thanks in advance,

Posted by deadbilly 10 years ago

circuit troubleshooting help

Hi- First on an unrelated note, does anyone besides me see "A fatal, non-recoverable error has occurred" over on the Makezine forums when you try to sign in? I've been getting that for weeks! Anyway... I'm working on a variable power supply that uses a 317 to regulate the 18 volts coming from a laptop switching supply. There are two 5k 10-turn (for precision) pots with a switch so that you can have two "preset" voltages and switch between the two of them at will. There's a single output. There's also a little lamp (I used a micro mini 12v lamp instead of an LED because that's what I had) that goes on above the pot that's currently switched in. The circuit I built (schematic is below) seems to work more or less fine. 'cept there's two strange issues: First, although the pots are linear (not sure if that would make the difference or not), they seem to "flatten out" toward their upper range. The first six turns gets you from 1.2 to about 16.5 volts. Then the last four turns either don't change anything or they do so in _very_ fine increments so that you only get from 16.5 to just over 17 volts. That's in four whole turns of the knob. This happens for both pots. The second stange thing is that turning the non-activated pot will affect the current voltage. When you increase the resistance (turn the knob to the right), the voltage level actually drops! Conversely, turning it to the left will increase the voltage. Remember, this is the switched-off pot. The switched-on pot works as it should (barring the mentioned weirdnesses). It looks like how much the voltage changes depends on how many turns you've given the activated pot. I suspect this has to do with me using a SPDT switch instead of a DPDT and maybe some voltage / current bleeding through the lamps and into the adjust pin, or something. But I ca/n't figure out why the switched-off pot would do anything. Anyway, take a look at the schematic. Is there anything I've done wrong that I'm missing? Should I, um, switch (*cough*) to a DPDT switch (something like the second schematic)? I used the SPDT cuz that's what I had. Anyy help is appreciated, Thanks!

Posted by deadbilly 11 years ago


I am using a MOSFET with a remote control momentary switch to turn a 1.5v mini DIY motor, which in turn controls the movement of a tiny plastic mouth to simulate speaking.   My issue is this.....the MOSFET I have calls for DC 3v-5v powersupply.   When I use 3v, the battery drains very quickly.   I've found no such thing as a SMALL 5v battery in the U.S., so I switched to 6v and it works just fine, but I am worried I will damage the MOSFET.   Here is the spec info from the seller (we are using Version A - DC3v-DC5v).  Product Description 1. Working Voltage: A: DC3V-DC5V     B: DC3.5V-DC12V  Optional                                   2. Max Load: 1A (have better load less than 700ma)  3.  Working Frequency: 433.92MHz   Working Current / Quiescent current : 7ma/H  4. Frequency Deviation: more or less than 0.2MHz  5. Working temperature:  -20'C- +80'C  6. Receiving Sensitivity: ≥-110dBm  7. Output State: A: Input DC3V-DC5V  Output DC3V-DC5V 

Posted by croswords 1 year ago

Make your own Laptop Power Supply from a modded ATX (desktop) power supply

There seem to be plenty of Ebay laptops that are being sold without power supplies. I've seen a few instructables where people are taking their desktop ATX power supply and making a bench power supply. From these bench supplies people are powering electronic circuits as well as other things. SO, that being said should you be able to power laptop computers from these ATX supplies? IF so, how would you go about doing it? Thanks! JP

Posted by jpl500 10 years ago

Convert an ATX power supply into a regular DC power supply

I did this project https://www.instructables.com/id/Convert-an-ATX-Power-Supply-Into-a-Regular-DC-Powe/ just today, but all the results came out negative voltage (e.g. -11,45 on the 12v) on the multimeter. Did I do something wrong or is it supposed to be like that?

Posted by kithso 9 years ago

splicing a power cord together

I want to make a laptop power supply cord longer by connecting two power supply cords together. My question is? one power supply cord has a ( RED WIRE AND A WHITE WIRE) and the other power supply cord has a (WHITE WIRE AND A GREY WIRE). Which wires do I solder together to make the wiring correct.

Posted by eljero 6 years ago

How do i connect some wires to a power supply?

I know nothing about electronics but i need this for a proyect. So i have some LED lights that come with positive and negative wires to connect to some sort of power supply (i need recommendations for cheapest!). My guess is i need some sort of power supply with the wires out so i can "twist together?"(or make them come into contact?) the negative of the LEDS with the negative of the power supply and positive with positive. I dont know if that's the way... and what would be the cheapest power supply if the LED's wires are 12v?

Posted by yerbamala 8 years ago

UPS Uninterrupted Power Supply

Just an open forum about UPS, the pro's/con's.... What do you use yours for? Lately Ive been thinking about getting one, then ask myself "Why?" I don't know, but still think it could be useful. Sooo, do you use it for a certain purpose? Do you buy it, just to strip it for parts? Or maybe IBLE idea's on uses for an UPS!

Posted by killarowa 10 years ago

Did I fry my DC power supply with AC?

Hi yall, I was a very stupid person tonight, but I have learned from my mistakes. In short I fed my DC power supply AC voltage INTO it, I was working on a subwoofers power board this afternoon, trying to diagnose why it is continually blowing fuses, anyway later I finally figure out that the 8A bridge rectifier is visually burnt as well as two small ceramic caps near it, taking the most obvious route I replace them with the same spec parts and power on, no activity but its not burning fuses at least for now. I usually have my multimeter connected right to my 40V old "Lambda" (crap brand) power supply on the same test leads, so I can get an accurate reading of how much power I am putting INTO the circuit. I rarely work on live circuits and should have known this. I attempt to get a reading with the meter while the sub woofer is plugged in and turned on. Little do I realize that the meter and the power supply are both the same leads, so I am putting AC power INTO my power supply where it should only be outputting power. I of course see the power supplys indicators light up and show a spike of the max 40V and then slowly dying down to 0 then I hear something fizzle and smell electronics heating up. I shut it off obviously after only about a few seconds Now I cant even get it to power a lamp or LED, NO MORE POWER. Should I cut my losses and just get a new power supply or try and salvage mine?

Posted by jackillac92 7 years ago

High Current Power Supply

For a project totally nonrelated to my tesla coil I need a way of regulating a voltage down to 36 Volts at 8 amps. My transformer (or a bunch of transformers hooked together) is suppose to have an output of about 38 volts at 8 amps, yet the voltage (with no load) is actually around 60 volts... Basically I need a way of regulating this voltage. For saftey, lets say the max input is 70 volts and it should be able to handle 10 Amps. The output voltage should be 36.

Posted by guyfrom7up 10 years ago

Need help with power supplies

I've been reading about electronics for a while and watching the Make podcast and I've finally started making my own projects. Anyway I have some cordless tools with 3 extra batteries but only one of them still takes a charge. So I thought it would be cool if I could put a power supply in one of my dead batteries so that I could plug it into the wall. I've been looking around my garage and thrift stores for a wall wart that would get the job done (the batteries are 19.2V Craftsman batteries I think they pull about 2000ma) but the closest I've been able to find is an old laptop power cord has a DC output of 19v and 3.9amps. So I'm not sure if that will work or if the extra amps will burn out my tools or something. Does anyone know if it would work? If not how can I dial down the amps?

Posted by cannedham160 9 years ago

2 Voltage Regulators, 1 Power Source?

Is it possible to use two voltage regulators of different values with one power source?

Posted by flagrantfouler 9 years ago

reducing current on a power supply

So I am trying to reduce the on the current power supply I have from an old router. The out put is 12v DC 800mA (.8A). I want to use it to run a man 12v .3AI just wanted to make sure I did my math right and to make sure I didnt miss anything.Ohms LawI = V/RR= V/I V = 12 I = .812/.8 = 15 ohms resistance in theroy_Current on the fan is .3 A, I am assuming that is the max. So desired current is .25I = .25 V = 12 R is current resistance, X is additional resistance Q=(R+X)I = V/QQ= V/IR+X = V/IX = (V/I) - R V = 12 I = .25 R = 15(12/.25) - 15 = 33 ohm resistance neededSo I would need a minimum of 33 ohm resistor. Am I correct?Sorry for the explicitness of the math, its been drilled into me to show every step.

Posted by dragonkeeper117 9 years ago

Are high power resistors really neccessary on a benchtop PSU conversion?

Was looking through the site and I was just wondering--why all the huge resistors on the bench-top power supply conversions of PC Power supplies? From personal experience this seems like a waste of perfectly good electricity.I know that they require some current to just stay on however in designing a project for my school's Engineering Technology department I found that the heat generated by such a small resistance (Around 10 ohms) was unacceptably high. Originally I was looking at Instructables and this sitethis site for inspiration but all the cooling measures taken to prevent the high power resistor from becoming a hazard seemed rather silly. A few calculations and experiments later with the 250 watt power supply and I determined that 160 ohm1 watt resistors and 1K 1/2 watt resistors were perfectly acceptable for the purpose of keeping the PSU awake and functioning. I connected one of each between each voltage and ground. According to calculations I can get away with dissipating a grand total of two watts or less spread across multiple resistors.The current divider rule dictates that if you add resistances in parallel, the resulting resistance will be smaller meaning more current will flow through the overall circuit. However this increased current will divide itself across the parallel resistances according to the rule Ix= RtIT/(Rx+Rt). The current through and power dissipated by the resistor you've soldered into the PSU will not change enough to be significant no matter how large or small a resistance you attach in parallel with it--with the exception of an effective short and what in God's name are you doing intentionally shorting the terminals of your bench-top PSU? Now several months later, the PSU is still operating happily and powering multiple micro-controller projects on a display board. Therefore I can reliably conclude that the high-power 10 ohm resistors in many computer power supply conversions are probably a gratuitous waste of wattage. You can get away with using a higher resistance and a resistor that dissipates much less current.

Posted by Psickattus 10 years ago

Can I wire an LED directly to an AC DC power supply?

Hi everyone,  This is my first time posting on Instructables.com so please forgive my noobness! Here is my issue: I have an idea of a really nice lamp to make for my girlfriend using a single 8W High-powered LED (http://shop.rabtron.co.za/catalog/high-power-white-p-7492.html) powered with a 12V 500mA AC DC Adapter (http://shop.rabtron.co.za/catalog/adaptor-500ma-fixed-p-6289.html) First off, is this possible? If not, why not and what is the correct way to go about it? Secondly, will this LED be bright enough for a desk lamp?  Thanks all! Happy instructing!

Posted by Shampoo1014 2 years ago

5 5mw lasers powered by one 120V outlet

Any comments or advice on making this happen? Im looking at buying five of these....http://z-bolt.com/MODR-red-laser-module.htmland hooking them upto a wall transformer off of a 120V outlet.

Posted by mnc615 9 years ago

request, 12v dc-12v ac power supply

Why?  So I can run a pile of 'pro' audio equipment on of a parade float without resorting to a generator or an off the shelf 120vac (barely) inverter. The equipment I'm talking about is a pair of 4 channel wireless mike receivers (8 mikes total) and a 10 channel mixer.  Other input comes from an MP3 player or CD player.  We also have an AM/FM/HD radio on board for those long waits in parade linup.  The power amp is an automotive (12vdc) unit, 4 x 1000 watts.  Main power is a pair of deep-cycle NAPA (optima clone) spiral cell batteries topped-off from the tow vehicle via a charge isolator.  There is also an 35watt solar panel (again, for those long lineups) run through the charge isolator.  The solar panel maintains the batteries while the float is parked or in storage. Cracking open the gear we have, every single one of them uses a 10:1 step down transformer to drop 120 vac line to 12vac before dumping it into the mainboard. It looks like 12vac @ 3 amps will do it for the wireless mike receivers and mixer, but why not shoot for 5 amps to be safe? Ideally, there would be some serious filtering and regulation/protection on the output. In a Perfect & Ideal world, there would be multiple 12vac outputs each capable of 2 or 3 amps and isolated from each other. Too much for a request?  You never know if you don't ask. And, in advance, many thanks! 

Posted by snoeclipse 8 years ago


I'm building a power supply for a cnc router powersupply. The output has to be 36 volts at 12 amps. I'm going to use 6 of the 25.2 volts, 2 amps transformers at radioshack (I have a coupon). When I rectify it it should be about 36 volts. Couple questions about transformers 1) don't transformers essentially short out an AC socket? I don't wwant to start a fire. 2) how can I have a LED indicator that indicates that each transformer is working? I don't want to use a huge resistor, because that seams inefficient. 3) how big of a filter capacitor do I need? I have a 33000uF capacitor, think it's a bit overboard? I know I need at least 4800 uF for just stuff like motors, but the only capacitors I have that works above 50volts is that capacitor. 4) can you connect AC in parralel? Can someone draw be a diagram?

Posted by guyfrom7up 10 years ago