### Power Supply

With this circuit, does it matter how many amps the input is rated at? The output is supposed to be 2 amps at 9 volts

Topic by TheLostAmish   |  last reply

I need to make a 6.5 vdc - 500ma power supply I have no clue how to make it 6.5v. any help is deeply appreciated

Question by BluTiger   |  last reply

### 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!

Topic by guyfrom7up   |  last reply

### Computer Power Supply?

Can i use a 20+4 pin power supply on a 24 pin motherboard? THANKZ!!!!

Question by sci4me   |  last reply

Hi Guys! I need some help. I recently got several pc power supplies and I don't know how to turn them on. That sounds stupid, but I don't really work with them much. I tried plugging it in expecting the fan to at least turn on, but nothing happened. No outputs from any of the leads either. What am I doing wrong? Thanks!

Question by transistorguy   |  last reply

### 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?

Topic by guyfrom7up   |  last reply

### power supply help

Hey I need help building a pedal brick power supply like the one here. i could just buy one but it wouldent be as fun, and i would rather build one if any one can help or knows of a schematic with multiple 9 volt outs i would appreciate your help.

Topic by chrischavez   |  last reply

### PSU Power Supply

I built a PSU bench power supply, but it isnt outputing the right voltages. It just out 5v for all lines(12v,5v). It has a purple wire that is said to be the stand-by, but the psu wont start unless it is connected to the 12v or 5v line. It also says that you have to have the brown sense wire attached to the 3v wire but this seems to do nothing. How can I make this thing output the right power(12v @ 22A, 5v @ 50A)?

Topic by tylerb   |  last reply

### simple power supply

I have a project that needs a 24VDC input, at only about 300 mA. I don't have any 24V power supplies, wall warts or anything else lying around, but what I do have is a 120 in, 24 out transformer, a bridge rectifier, and a large cap. Is there any reason why I shouldn't just use those? I'll put a fuse on it. I have some 317 voltage regulators but they dissipate too much to provide the full 24V. 317s are short-protected and the like, which obviously my little kludge wouldn't be, but beyond that, is it a bad idea? thanks,

### Power Supply and Driver? Answered

I've seen alot of the projects that have a power supply and a driver?  What's the difference between the two and why would you need both?

Question by lford4   |  last reply

### Flash Power Supplies

I don't have a lot of money to spend on stuff at the moment. What I do have is flash guns. Four of them in fact, three of which can be fired with triggers. Now I could invest in 16 rechargeable batteries. Or should that be 32 in case I run out? And a crap load of chargers.  And extensions cos we have no spare sockets in our house. But that just doesn't seem right to me.   Heres what I propose : 1) make some dummy batteries from wood with wire running through the middle.   Three of these go in each flash to carry the connections  2) a fourth dummy battery carries wires out of a small notch in the battery flap door 3) said wires are connected in parallel to a large rechargeable battery - I reckon a 6v from an old British motorcycle (fast draining) or from a granny wagon (deep cycle) should do the trick.  4) when I'm done shooting I charge this single battery from the mains charger I have (does 6/12v) I figure 4xAA batteries at 1.5v = a 6v battery, bu extra size should last longer, be more convenient than carrying around dozens of AAs and changing them and if I want to use AAs when our and about I still can   Any reasons tho wouldn't work or I shouldn't do it?

Topic by ohowson   |  last reply

### Power Supply and LEDs

Just wondering what i could do with my old computer power supply? THANKS.... Also...What bout LEDs ....what can i make with them??? THANKS

### power supply for LED's? Answered

I have a strip of LED's that have a warning that's says use only with a 12v class 2 power supply. Is this referring to an AC/DC transformer? Should I be able to run them straight from a 12v battery? If I am using a 12v battery is the class 2 circuitry still needed?

Question by MDheliMech   |  last reply

### Gateway Power Supplies?

I have a Gateway 24" LCD monitor, model # LP2407, with a bad power supply. Does anyone know where I can purchase parts for Gateway products? Or does anyone know the company that produces the monitors for Gateway? Gateway is useless, they directed me to companies that are resellers or Gateway's computers. I've checked with several local repair shops, all said, "Good luck, buy a new monitor."

### LED Power supply?

I have approx 200 flashing LED circut boards that I want to make a twinkling display from. Each board has a single LED that flashes about every second, each board also has a single 3v cr2032 lithium battery powering it. What Id like to do is remove the battery on each one and wire them to a DC power supply that can be plugged into 120VAC. So I actually have two questions: Should I wire these in series? Or parallel? What size power supply would I need? Heres a link to a picture of what I have. http://www.rocketproduction.com/wirefree-leds.php Thanks (in advance) for all your help!

Question by McBeeRob   |  last reply

Is there a fairly simple circuit, method to making a desktop power supply running on 240v a.c mains supply with a user controlled variable output say 0-24v D.C with variable ampage upto say 1 amp. I may be over simplicating thing in my head but is it just a case of a transformer taking my mains input down to the upper most requirement ( 24v @ 1amp ) on the output, and the using some type of variable resitors on the output to further restrict the output to my requirement. I would be grateful for any guidance and information on this topic. Thanks to the community in advance.

Question by mickcaulton   |  last reply

### Are these power supplies good?

The cheap bare metal power supplies from ebay or other sides have been reviewed many times on youtube and people have found that they are actually decent. But I cannot find any reviews of the sealed plastic kind of power supplies. The "bare metal" ones I am talking about look like this, and the "sealed plastic" ones look like this and this. Edit: None of your replies answer my question. I am not asking which one I should choose, I am asking if the plastic ones are just as decent as the metal ones. There are a few reviews of the metal ones, and people have found that they are actually quite decent. Here are some: https://www.youtube.com/watch?v=vwFrP7uK5lM https://www.youtube.com/watch?v=71NWT5vrbk8 But I cannot find any reviews of the plastic ones, so I don't know if they are just as good. I am asking if anyone has gotten any of these and made a review with some tests, or knows of a review of these.

Question by poiihy   |  last reply

### Led Power Supply?

I am going mad over trying to figure out what power supply I need. I am making an arduino controlled aquarium fixture and plan on using 30x3w leds. From what I understand using resistors could cause fire and I don't want that of course. I like the look of laptop drivers like this one http://www.gapsupply.com/LED-Power-Supply-p/12v-dc-nwp-96w.htm but I cant figure out which one I need. I have seen all the instructables for this and everyone seems to tape 8 meanwell drivers together. I dont want a big bulky ugly mess like that just one power supply to do the job. The smaller and more compact the better. I will be running 2 rows of white on the outside and one row of red in the middle. 10x3w leds per row. each row individually dimmable via ir and tft. here is the led specs. Whites: http://www.ebay.com/itm/390908787444?_trksid=p2059210.m2749.l2649&ssPageName;=STRK%3AMEBIDX%3AIT Forward Voltage: 3.2-3.8V-700MA Luminous flux: 200-230LM Output power: 3w Light Color:  White 6000-6500K View angle: 120-140 LED support：Copper Life time:50000 hours Reds: http://www.ebay.com/itm/310834616296?_trksid=p2059210.m2749.l2649&var;=610229587957&ssPageName;=STRK%3AMEBIDX%3AIT DC Forward Voltage:2.2V~2.8V Forward Current: 600-700mA Output power: 3w Light Color:  White 6000-6500K View angle: 120-140 Any help and ideas is greatly appreciated. Thanks

Question by charles.terhune

### Problems with power supplies.

I made a small circuit board which is a proximity sensor that turns on or off a small philips genie light(its a small white tubelight like light ).i tried powering it up with a 9v battery and it works fine and the relay on the circuit board switches the ac220v load and the light goes on ,however when i try powering it up with a 10vdc adapter the relay on the circuit board keeps clicking(here i have not used the ac load to switch the tubelight,i was just experimenting and came upon the problem) .what should i do .pls help me.

Question by Strontium   |  last reply

### transformer less power supply?

I needed around 500mA current to run my mini project, so i decided to go through the transformer less power supply instead of normal transformer used supply.Since the other power supplies are quite bulky. But the problem occurred is, the supply doesn't supplies minimal current to run the project. Please, help me with this problem and suggest some alternatives or amendments to be made.  I have uploaded a picture of my design.

Question by ShuvamP   |  last reply

### Questions on the Building the Power Supply

Does the wall wart need to be AC or DC. Also how does the potentiometer go in the circuit? I bought a 10k volume potiemter here:[http://www.radioshack.com/product/index.jsp?productId=3064080] Will this work?

Question by jfrazi10   |  last reply

### 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.

Topic by Shorty954   |  last reply

### PC Power Supply To Power CB Radio?

I have a cb radio my uncle gave me 12v 2-4 amps.. I have an old computer with a power supply with lines for 12v 6amps and 12v 8amps. is there anyway I can get this to power my cb radio without blowing the thing? EDIT I forgot to mention, this is a mobile cb radio, I'm trying to run it in the house, which is why I wan't to use a pc power supply to run it....

Topic by acer5050   |  last reply

### 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.

Topic by omnacron   |  last reply

### 15 volt power supply help Answered

I need a 15 volt power supply. is there any other circuit than using a 7815 and two batteries?

Question by metsfan1938   |  last reply

### how to give power supply to a speaker?

I have spekers of an old radio in working condition...but to use it as my laptop speakers i need a power supply....so what would be its voltage, current and power ratings and how could i make it??

Question by navinn_11   |  last reply

I want to run my ps2 in car, Any circuit to drop 12v to 8.5V at 6amps the lm317 circuit is not powerful enough

Question by ARJOON   |  last reply

### 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

Topic by WIZZIEDEE   |  last reply

### transformerless ac to dc power supply conversion?

Input of AC supply is 24v  output wanted from in DC of 2.5amp Without using transformer. please help.

Question by snehap22   |  last reply

### how to make a 12 v regulated power supply?

I want to make a 12v power supply.the input voltage is 220v\50hertz.please guide me with full and complete construcyion and making of power supply along with the equipments and their configurations.                                                                                                                                                                                                                                               thankz.

Question by hashmi43   |  last reply

### What is does 200 mA stand for on a power supply?

I am trying to figure out the amps on a power supply. It has an input of 120v, 60 Hz, 4w. Output is 6VDC, 200mA. I just don't know what the mA is.

Question by bbierbaum   |  last reply

### i need to build a tattoo gun power supply?

I have a real tattoo gun but i dont have enough money to buy the power supply so im trying to buil one . Does anybody know how? or is it even possible to do

### How to reduce the voltage of a laptop power supply without reducing amperage? Answered

Hi guys, I have a laptop power supply with an output of 19V, 5.6A. I want to use it to power a small stereo amplifier that needs 12V. I want to make an adapter or something that will reduce the voltage without affecting amperage for use with the small amplifier, but I also need it supplying 19V for the laptop. Is it possible to make do it this way: [19V power brick] --> [adapter/transformer] --> [amplifier]?

Question by Tristan GianP   |  last reply

### I want to build a power supply input 12 or 24 VAC output12VDC? Answered

Question by Basem Salep   |  last reply

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

Hello all ! I'm new to instructables and Iâ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.

Topic by testpartner   |  last reply

### can I use a 10k pot instead of a 5k pot in my power supply?

Its a o to 24vdc power supply . it calls for a 5k pot. want to know if i can use a 10k pot . and what will be the diffrents

Question by mojomojo99   |  last reply

### Will you please help me to design a power supply of 12v and 1amp with calculations for selection of right components ?

As above mentioned i would like to have the basic knowledge regarding the designing power supply. Here i want the selection criteria for all components of power supply .I would like to have basics of the calculations or formula regarding selection of values of capacitors used in design.          Kindly help me please!!!!

Question by Anuja Sham Londhe   |  last reply

### How to make a regulated power supply with 1.5, 3, 4.5, 6, 9, and 12 volts dc output?

Kindly, please give also the schematic and block diagram and the parts to be used with PCB design. Thank you very much!

Question by ymx   |  last reply

### I would like to power a 12v dc 10amp water pump with a 120v power source...Ideas???

What could I use to do this without actually buying a \$100 converter...I have read some instructables on using a pc power supply to make a bench power supply...but that seems like more than I need...any ideas???

Question by wingrider78   |  last reply

### Any one here have an idea as a configuration to turn on a Astec AA20790 computer power supply?

I have two ASTEC power supply, but I don't know how turn this on, I want the 12v output with my cnc printer, but in internet and youtube they don't have so much. Please, can you help me my with give me some diagram or configuration with this power supply. I try to put a resistor with com and 12v cghs something like that. But the power output stay in 0v and the fan stay too in low power. This russian guy put a cable but he doesn't say how active the output, I think is the same thing I wanted to do but doesn't turn on. https://newauctionstatic.com.ua/offer_images/2016/10/10/03/big/D/dl1oLB3EXK7/astec_aa20790_blok_pitanija_12v_14a_dlja_videokarta.jpg Thanks a lot and some kisses.

Question by paberu   |  last reply

### Are there any instructables or schematics available for power supplys36vdc at 5amps with volt meters and amp meters?

I need help in schematics only in power supplys at 36vdcplus at 3amps to 5amps with meters for determining amps in any given scxhematic.

Question by kbyrne   |  last reply

I have posted 2 other questions on the variable power supply. I have put together 3 of them and none of them worked! Yes I'm a newbee to electronics and I guess I just dont understand how to read the schematic. One of the answers said that this circuit would not power a motor even if it is a very small one as this is like a direct short. Could someone please explain this. Regardless I feel so defeated, I have spent a week on this with no success. could someone please send me the wire connections as they would be on the circuit board. I was wanting this to power a small dc motor, so if this is not the circuit I need could someone send me a schematic with actual wire connections for a circuit that will give me variable power to control the speed of a dc motor. Everyone has been so nice and I apologize for my ignorance! I just want to learn so bad!!! No one locally to help me. Thanks in advance!

Question by pollock9131   |  last reply

I have a power supply that is rated at 12V on a couple of pins (8 pin connector) but it does not seem to work. I suspect that one pin (called remote) needs to be activated, but I am not sure what would make it stay up. I have included a drawing from the power supply label.

Question by pbraatelien   |  last reply

### 9v battery simulation?

I want to use a lab power supply to run simple ohm's law experiments instead of using a 9v alkaline battery. One of the experiments uses a resister in series with an LED to show the effects of how a resister limits current. I can set my lab power supply to 9V but I don't know what current to set it to in order to be the equivalent of the 9V battery. Can anybody enlighten me please? I'm just getting into learning electronics.

Question by woodyd   |  last reply

### how to make a dc current from ac current?

I m making a power supply project which works on dc. but i don't wan't a battery, so i wanna connect it direct to ac to dc convertor i don't know how to make it :[...... Anyone who answer plzz give detail summary with a perfect diagram of the circuit

Question by arihant   |  last reply

### cant get 5k pot adjustment to work. what am i doing wrong? does R2 hook into Adj?

Question by hillbillyboy_316   |  last reply

### What this button does?? Answered

The images are given below(one with closer look and one with outer look) i have marked one red button and i want to know what it does and it has two faces when i push it down it has 15 written on it and when i pull it down 230 is written there! Do any one have any idea?

### How to convert 300 volts DC to 30 volts DC?

Alright so i made a simple full bridge rectifier (http://www.electroboom.com/?p=544) credits to Medhi Sadahagar. I modified it such that it works with 240 volts mains instead of 120 volts mains. my capacitor bank is 2.4 mF and 400 volts. However, the output is 312 volts DC and I require around 12-36 volts DC at minimum 10 amps to power a ZVS driver (by Plasmana). I tried a voltage divider but I think the power rating of my resistors was not enough as one of them heated up and broke. I need help in designing or making a suitable circuit to reduce 312 volts DC to 12-36 volts DC at 10 amps minimum. Please help me and have a great day :D

Question by BenderSanchez   |  last reply

### How to properly bridge 2 mono jacks using a 1uf capacitor and connect to rheostat?

Hello everyone, I am struggling on the proper way connect a few parts in my power source. At the moment I am about to wire my rheostat to a mono jack. From there I need to wire a 1uf capacitor to a 2nd mono jack. I do not understand where to connect each wire. I know how to wire the rheostat to the first jack but from there I do not know how to properly bridge the 2 jacks with the capacitor. I know I need to connect both jacks but how do I wire this? Do I connect the capacitor between both "ground" leads on the jacks? Does this also constitute  connecting both jacks in general? Also, the 2nd jack will be connected to the rest of the negative circuit in the source. I really hope I explained this well enough. I am new to electronics and I am still not that familiar with terminology so please bare with me. I would appreciate any help offered. Thank you in advance!

Question by alp0204   |  last reply

### problems with external power supply

I cant able to run my arduino in external dc power supply.and also when i give my shield  a external power supply of 9V battery and 5V from the arduino, the battery is lasting only for 30 minutes.can i know what is happening & how can i overcome this?

Question by harish.rahman.75   |  last reply