Low AC to DC conversion

Hi, I'm looking for simple way to convert a low AC into a usable DC, of say 4 - 5 volts for charging batteries. I recently saw one discussed online, specced at costing about a quarter, but couldn't find a way to do it, or a way to purchase something like that. Thanks!

Topic by fafnir665 11 years ago  |  last reply 7 years ago


how is ac current generated? Answered

Ok, so I was under the impression that brushless motors were AC motors (and therefore conducted AC current), until recent internet searches proved me wrong. I am curious how AC current is conducted, is it conducted using brushless motors? Or is it a different type of motor that will generate such electricity?

Question by A-Nony-Mus 8 years ago  |  last reply 8 years ago


Low voltage AC?

How can I make a simple circuit that will produce alternating current using 1.5 to 9v power supply? This is an experiment for using an AC voltmeter - that is, making the needle move.

Question by brandegor 9 years ago  |  last reply 9 years ago


How to increase AC current without using amplifiers and external power source? Answered

Iam having 12V AC and the current 100mA.When i apply the 12V AC to secondary winding of 5V transformer.The voltage gets boosted up to 64V.I don't want voltage to be boosted,instead i want to increase the AC current without using transistors,external power sources,etc.Like the transformer which is boosting voltage when applying AC voltage at secondary.I need to increase AC current only and not the voltage.I want these to be done without using amplifiers.Because amplifiers uses external power source.Any one tell me how to increase current.Otherwise is there any way to increase AC current by reducing the voltage?

Question by Rajkumar2506 1 year ago  |  last reply 1 year ago


Ac current limiting per light bulb? Answered

Dear all.. Please help me to know: how wattage of light bulb(please see photo) is needed for limiting my circuit 120ac 60 watt maximum Thank you so much.

Question by lam 5 years ago  |  last reply 5 years ago


Trouble out putting a DC current to AC current?

Im looking for a way to use a 9v DC current to regulate an AC current.  I have a set up a diagram of my problem: I thought of using a relay but i would like the light to be able to dim not just either be on or off, then i thought of a transistor but im not sure if that will work with both ac and dc at the same time.  I could really use some help here.

Question by keeperrico 8 years ago  |  last reply 9 months ago


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 8 years ago  |  last reply 8 years ago


What is the easiest way generate AC from a natural source, and then transform it into DC?

I have a school project where I have to generate AC, it can be a small amount, using wind or whatever; and then I have to turn it into DC. To be honest I'm a bit lost, I've read you can do it with an alternator, but I couldn't find one in my local electronic store. I've also read that with two magnets and a square shaped wire, but I don't know how plausible it is to do it this way. Any help is welcome, also if you could help me with how it should be connected would be great.

Question by JorgeV115 2 years ago  |  last reply 2 years ago


Homebuilt AC

Hello again everybody, bwpatton1 here with another one of his strange Ideas..... not as dangerous this time. Well, we built a gameroom, and currently it has a 10000 BTU window unit, in the South Texas summer it has a hard time keeping up, it also uses 900watts, well 900watts by itself isnt bad but we have two of these b/c we have two floors. I was wondering if i could build an AC to help supplement the run times of these AC's. My idea was to get an old refrigerator (and keep it outside) and run copper tubing through the freezer and into the refrigerator area and out of the refrigerator. Then, run this copper tube to a copper coil with a blower fan. Sound good sofar? Then I would run the end of the tubing back to the top of the freezer, somewhere in there there would be an inline pump somewhere............ OH and the lines would be filled with water/antifreeze??? Does anybody think this would be efficient enough to build? Or am I just wasting my/your time Diagram- the thing to the left is the refrigerator, and the squiggles are copper coils, and the thing to the right is a blower/coil. You were supposed to be able to read the writing on the diagram but the camera wouldnt cooperate

Topic by bwpatton1 9 years ago  |  last reply 9 years ago


can i increase current in a ac current without decreasing voltage?

Question by lohithg 7 years ago  |  last reply 7 years ago


how can i generate a small amount of ac current...?? Answered

I want to generate 9-12 v ac current....is there any simple way to do that...?? secondly....if i connect two wires from a  dc motor to a bulb, and then rotate the axle of the motor, then is the current produced by the motor the ac current..??...plzzz tell me..!!

Question by kool.mukesh 9 years ago  |  last reply 9 years ago


How do I measure AC current (0 - 7 Amps) using a microcontroller? Answered

 I know how to design microcontroller circuits using PIC/ATMega processors but my analog experience is lacking. I understand I can use a transformer to transduce the current going through  a cable, or use a Hall-Effect based transducer in a similar fashion. How do I scale the output voltage of the transducer (DC in the Hall effect, and AC in the simple coil) to match the -VRef to +VRef swing of the A/D converter built into the microcontroller?  The only thing I know about analog circuits is "ground" is the place you grow roses... Thanks, David, Melbourne, Florida

Question by dk-info 9 years ago  |  last reply 9 years ago


Transformer current restriction? Answered

I am aware mostly how transformers (AC - AC) work, but I am lest informed on a few key parts.  I know there is a direct relationship between windings and voltage as well as an inverse relationship between voltage and amperage. The thing I don't understand is what limits the current produced by the transformer.  I know you can keep droping the secondary windings to increase amperage, but eventually you get to a point you can no longer do that.  To overcome this one can use three sets of windings wired in parallel which will retain voltage but increase amperage.  The amount of amperage is still limited to the maximum throughput of the primary, but how do you actually find this out.  If one wanted to make a variable current AC welder, it would be relatively easy to predict the voltage, but establishing a potential amperage is more difficult.  What actually establishes the maximum output of a transformer because in some cases the max current is reached long before the actual failure, and is there a way to predict the end product.  P.S. I am not looking for the answer they use voltage/current limiting circuts ect...  I am looking at something like a pole pig which maxes out output before internal failure and contains no additional circutry, not a wall wart

Question by jj.inc 5 years ago  |  last reply 5 years ago


If I connect an AC fan motor to an engine of some type, will it create AC current? Answered

Or am I completely wrong in thinking that a motor can be a generator if you apply force to it instead of applying electricity?

Question by Funk_D 9 years ago  |  last reply 8 years ago


How to pulse dc current? Answered

Hi! I was just wondering if people could give me some different ways to pulse dc current. I am trying to power a transformer with dc. Thank you in advanced.

Question by tesla man 6 years ago  |  last reply 3 years ago


Do audio devices put out alternating current? Does the current ever switch itself?

Hi I'm making a prop Geiger counter for Halloween, and i was going to have bi-polar LEDs on it depicting if it is safe or not to proceed. I have worked out all the main issues with making a prop Geiger counter, Producing the sound, amplifying it, and distributing it. I was going to have one channel of my MP3 player play Geiger counter clicks and the other  channel square waves to drive a transistor to drive the Bi-polar LEDs I was going to have Red LEDs light up to the positive part of the wave, and the Green to the negative. This is where i ran into a small problem, i don't really remember if Electronically produced sound waves have both Parts of a wave (look at the picture), or of it just produces a positive pulse without reversing polarity. I will be using a computer speaker amplifier for this project Thank you! (basically, i need to know if Computer speaker amplifiers produce AC current)

Question by Sandisk1duo 8 years ago  |  last reply 8 years ago


why do we receive AC power in our homes if mostly everything converts it to DC?

*except lightbulbs and welders. maybe water heaters?

Question by k_man93 9 years ago  |  last reply 9 years ago


Need help changing an AC circuits frequency

Alright, so I have a question about an alternating current circuit I was working on.  The wall outlets I'm drawing power from are AC at 120V, and 60 Hz, but I need it to be 120V at between 60 Hz and 1000 Hz.  A variable system would be nice, but I'm not picky.  How would I do this?  Is my only option to convert the power to DC, and then run it through an inverter?  I would like to be able to do this with a small circuit I could build, something that would fit in a project box.  Any ideas?

Topic by Avren5 8 years ago  |  last reply 8 years ago


Parts info please

Hi all: Does anyone know of a part that will swith  240v AC current on & off for short periods of time like a pulse effect ?. Thanks.

Topic by tezza1 7 years ago  |  last reply 7 years ago


My Current 100 Favourite Songs

Inspired by Viccie's topic, I made my own. It took about an hour. 1. Riff Raff - AC/DC 2. Paradise City - Guns 'n' Roses 3. It's A Long Way To The Top (If You Wanna Rock 'n' Roll) - AC/DC 4. November Rain - Guns 'n' Roses 5. Sweet Child 'o' Mine - Guns 'n' Roses 5.5. American Idiot - Green Day 6. Let's Get Rocked - Def Leppard 7. Dirty Deeds Done Dirt Cheap - AC/DC 8. You Shook Me All Night Long - AC/DC 9. Dream On - Aerosmith 10. T.N.T - AC/DC 11. ELMO'S SONG! 12. Back In Black - AC/DC 13. Rocker - AC/DC 14. Thunderstruck - AC/DC 15. Shot Down In Flames - AC/DC 15.5 The Wall (Pt II) - Pink Floyd 16. Whole Lotta Love - Led Zeppelin 17. Fallen Leaves - Billy Tlent 18. Red Flag - Billy Talent 19. Surfing With The Alien - Joe Satriani 20. Devil Gate Drive - Suzi Quattro 20.5 My Apocolypse - Metallica 21. Beatin' Around The Bush - AC/DC 22. Welcome To The Jungle - Guns 'n' Roses 23. Moonshine - Savage ft Akon 24. I Believe In A Thing Called Love - The Darkness 24.5. One - Metallica 25. The Furor - AC/DC 26. Love At First Feel - AC/DC 27. Let There Be Rock - AC/DC 27.5. Whole Lotta Rosie - AC/DC 28. Layla - Eric Clapton 29. Heartbreaker - Led Zeppelin 30. Hard As A Rock - AC/DC 31. Sunshine Of Your Love - Eric Clapton 32. Always With Me, Always With You - Joe Satriani' 32.5 Nothing Else Matters - Metallic 33. Bohemian Rhapsody - Queen 34. When I'm Gone - Eminem 35. Chinese Democracy - Guns 'n' Roses 36. Verona - Elemeno P 37. Black Night - Deep Purple 38. Fat Bottomed Girls - Queen 39. Paranoid - Black Sabbath 40. Livin' On A Prayer - Bon Jovi 40.5. Battery - Metallica 41. Who Made Who - AC/DC 42. Hot For Teacher - Van Halen 43. Voodoo Child - Jimi Hendrix 44. Stairway To Heaven - Led Zeppelin 45. (Moved Up To Number 5.5) 46. Lonely - Akon 46.5. Pour Some Sugar On Me - Def Leppard 47. Sweet Home Alabama - Lynyrd Skynyrd 48. Sink The Pink - AC/DC 48.5. Photograph - Def Leppard 49. Are You Gonna Be My Girl - Jet 50. Make Love Like A Man - Def Leppard 51. For Those About To Rock (We Salute You) - AC/DC 52. Shake Your Foundations - AC/DC 53. Devil On My Shoulder - Billy Talent 54. Worker Bees - Billy Talent 55. Smoke On The Water - Deep Purple 56. Under The Bridge - Red Hot Chilli Peppers 57. Smells Like Teen Spirit - Nirvana 58. Walkie Talkie Man - Stereogram 59. Don't Cry - Guns 'n' Roses 60. High Voltage - AC/DC 61. Khe Sahn - Cold Chisel 62. Highway To Hell - AC/DC 63. Kashmir - Led Zeppelin 64. In and Out Of Love - Bon Jovi 65. Ramble On - Led Zeppelin 66. Purple Haze - Jimi Hendrix 67. Teenagers - My Chemical Romance 68. Give It Away - Red Hot Chilli Peppers 69. Stop Drop And Roll - Mareko 70. One Eyed One Horned Flying Purple People Eater 71. Walk All Over You - AC/DC 72. Cut The Curtains - Billy Talent 73. Live And Let Die - Guns 'n' Roses 74. I Wanna Rock 'n' Roll All Nite - Kiss 75. Message In A Bottle - The Police 76. Iron Man - Black Sabbath 77. There's Gonna Be Some Rocking - AC/DC 78. Ride On - AC/DC 79. Lights and Sounds - Yellow Card 80. Holidae Inn - Chingy 81. Rock 'n' Roll Ain't Noise Pollution - AC/DC 82. Have You Ever Needed Someone - Def Leppard 83. Not Many - Scribe 84. Holiday - Greenday 85. Hotel California - Eagles 86. Heart Shaped Box - Nirvana 87. Heaven Is - Def Leppard 88. Over The Hills And Far Away - Led Zeppelin 89. Hells Bells - AC/DC 90. Tears In Heaven - Eric Clapton 91. DT - AC/DC 92. Moneytalks - AC/DC 93. Alberta - Eric Clapton 94. Killer Queen - Queen 95. Rock This Town - Stray Cats 96. Stiff Upper Lip - AC/DC 96.5. I Love Rock 'n' Roll - Joan Jett 97. The Jack - AC/DC 98. Angie - Rolling Stones 99. Black Ice - AC/DC 100. Invisible Man - Queen I'll be always updating this list with song that i've forgotten to put in!

Topic by ajleece 9 years ago  |  last reply 9 years ago


What capacitors should I use for an ac tesla coil?

I have just finnished my tesla coil build and I had been using a dc flyback to power it.  Now I have a dual mot set up and it outputs ac. To rectify it would cost over $300, so I need to find caps with a good ac raiting. Does anyone know where to buy these?

Question by MasonG11 2 years ago  |  last reply 2 years ago


how do i make an ac current with a battery? Answered

Hi, i have searched over the internet many a time, looking for how to make pulsating dc or an ac current, however all my results end up with devices which use ac or pulsating dc, which is comming from some homemade ac-dc converter running of mains. now, i am trying to find out how i can use a aa battery to aquire an ac current, or pulsating dc current, preferebly using parts aquirable from a disposale camera. the reason i need ac or pulsating dc is so that i can build a voltage multiplier, and also a tazer. i have tried plasmanas instructable on making a worlds smallest shocker, but it just doesnt work, if you cant get the specific transistors and transformers only aquirable from polaroid brand disposable cameras. plus there are no details on where to buy the parts, or even their details, beyond resistance and capacitance values. the main thing though is that i need to make the pulsating dc or ac from a portable power supply, aka a battery, as i also wish to make a dc-dc boost converter to use on different components within my rc tank. please help, whoever can answer my question best will receive a " best answer"

Question by oldmanbeefjerky 8 years ago  |  last reply 7 years ago


How can I limit the current of my AC regulator?

Dear All, I am having a problem with my AC regulator that I use with my gadget. The AC regulator supply 12volts and 2.66 amps when connected to the grid. My problem is that my gadget used to be charged using 12volts and .660 amp, I noticed that when I plugged the AC regulator and connect it to my gadget it gets really hot after a short period of time. I want to limit the 2 amps so that the regulator then produce the required current. I have quite a bit understanding with electricity and I want to know what kind of resistor should I wire with my AC regulator for that to be able to supply the said amount of current. Also can I wire a thermostat or a fuse that will shut down the system if it gets to hot? Please help me anyone?

Question by mitchiko 7 years ago  |  last reply 7 years ago


Is it possible to live in my small trailer on Direct Current only?

How can I do it? I'm living off the grid with 2 deep cycle 12 volt batteries. Wouldn't my batteries last longer without converting all the time to Alternating Current? Can't I just use 12 volt accessory plug-ins? What do you think of DC vs. AC? I'd like to also start adding solar panels as I can afford to, one at a time.

Question by arnold54 9 years ago  |  last reply 9 years ago


Can I use a 10 amp 120 volt relay for more then 10 amps if the voltage is lower? Answered

I am currently working on a mini A/C with a TEC that draws 12V and 12 amps and the relays I want to control it with have a rating of 10 amps 120v. not sure if it is as simple as this but 10A*120V=1200 watts. While 12A*12V=144 watts so in my eyes this would work because there is much less power flowing through the relay but I would like to request advice from someone who is a bit more knowledgeable then I. Help would be greatly appreciated thanks a bunch. Harry

Question by harry88 4 years ago  |  last reply 4 years ago


How to measure max output current of transformer ?

Question by Rendydevara 8 years ago  |  last reply 8 years ago


Why DC current is not used in Homes? Answered

Why DC current is not used in Homes as it is more safer than AC current.

Question by Dipankar 7 years ago  |  last reply 10 months 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.

Topic by AnandC10 3 years ago  |  last reply 2 years ago


Homebuilt AC unit???

Hello again everybody, bwpatton1 here with another one of his strange Ideas..... not as dangerous this time. Well, we built a gameroom, and currently it has a 10000 BTU window unit, in the South Texas summer it has a hard time keeping up, it also uses 900watts, well 900watts by itself isnt bad but we have two of these b/c we have two floors. I was wondering if i could build an AC to help supplement the run times of these AC's. My idea was to get an old refrigerator (and keep it outside) and run copper tubing through the freezer and into the refrigerator area and out of the refrigerator. Then, run this copper tube to a copper coil with a blower fan. Sound good sofar? Then I would run the end of the tubing back to the top of the freezer, somewhere in there there would be an inline pump somewhere............ OH and the lines would be filled with water/antifreeze??? Does anybody think this would be efficient enough to build? Or am I just wasting my/your time Diagram- the thing to the left is the refrigerator, and the squiggles are copper coils, and the thing to the right is a blower/coil. You were supposed to be able to read the writing on the diagram but the camera wouldnt cooperate

Topic by bwpatton1 9 years ago  |  last reply 9 years ago


Run AC device on DC: An idea, could it work?

I need to run an AC powered audio mixer on DC current from a battery. Yes, I could buy a power inverter, but I want to make the system the simplest I can, and I also have an old small mixer I'm not using (that I can experiment on). I'm self taught on electronics, so please tell me if there's any inaccuracies in the following lines: My idea is to find where in the circuit AC gets converted into DC, and then at that point feed the DC current from my battery. I think that point would be right after the bridge rectifier. So, in shot: Can I connect de dc output from my baterry to the end of my audio mixer bridge rectifier? Thank you!!

Topic by FrancoMolina 2 years ago  |  last reply 2 years ago


Converting Dc to Ac

Ok this is my first post on this site so forgive me if i sound stupid...i like to tinker with things so just to tell a little about things i have done...completely rebuilt a pc..wired up an adapter for an old xbox to work on pc...the easier things....fixing frayed speaker wire....rebuilt/and upgraded a zune 30gb to zune 60gb the usual stuff...my most proud is overclocking my amd 64x2 4000+ to 2.9Ghz.....everyone said it couldnt be done...........anyways on to my question.......i want to know what all i will need to convert Dc to Ac power for a set of old desktop speakers i found in my closet.......i have an idea of what i want to be able to do.......put them in a backpack and make it portable.....currently i have two old 7.2v 1200mah Rc car batteries that i would like to use to power it.....and i also have a charger for them...it can charge and discharge...its old but works....so now my next step is what else am i going to need to complete this project...i dont know a whole lot about electricity but know enough to follow directions...if someone has already done this or knows how to and could walk me through what i need to do i would greatly appreciate it....

Topic by Celestial_Artisian 10 years ago  |  last reply 10 years ago


Please help! How do I lower the current strength (Amps) in a parallel circuit so I don't fry my LEDs? Answered

I have a AC/DC adapter that gives out 4.5V and 500mA, how could I lower the strength of the current so that I can connect four LEDs (4.5V, 20mA) in parallel and not fry them? Sorry if I ask the impossible, I'm a total electric beginner. Thank you in advance!

Question by dark_boshkarin 9 years ago  |  last reply 9 years ago


Does an electric fly swatter output dc or ac current?

 

Question by WerdnaN 9 years ago  |  last reply 2 years ago


How to run a single LED from AC current?

I've been reading up on a lot of existing posts and projects about people wanting to power LED(s) off of 120VAC. Most of the suggestions I see refer to the use of a wall wart DC power adapter to accomplish this task. In many cases, it would probably suffice. However, due to a very limited amount of space I have to work with, I need to make this project as thin as possible. I really don't have the room to accommodate a big wall wart adapter. Can anyone direct me towards being able ot make a single LED run off AC? I'd also like the ability if possible, to run it with a photo sensor to turn on/off night/day. Thanks! Dustin

Question by djc311 6 years ago  |  last reply 3 years ago


how to make a 240v 2A dc power supply?

I need a 240v dc power supply for a project but my pablum is ,i need to reduce the current up to 2 amps i know how to reduce the voltage but how i can reduce current ?

Question by vina1991 2 years ago  |  last reply 2 years ago


How does an inductor cause current to lag voltage in the case of an alternating current, and why is this bad? Answered

Basically, can someone help me with this: http://www.alpharubicon.com/altenergy/understandingAC.htm ? What are the EXACT physics behind it?

Question by Xellers 9 years ago  |  last reply 9 years ago


Reduce current but maintain voltage?

Do resistors reduce voltage or amprage? It's amprage as far as i know. I've got a power supply thag outputs 9kV at 300mA and I need to get it to 9kV at 0.2mA, someone suggested a 450kOhm resistor. When I phoned go get one they asked if I want a quarter watt resistor, what does that mean (1/4, 1/2 watt). I need to reduce the current comingfrom the power supply because I'm using it to power a fusion reactor and the diodes I have to comvert the AC to DC can only handle 0.02mA

Question by JunaidA44 3 years ago  |  last reply 3 years ago


LEDs off house current?

I have recently conceived a desire to pimp out small household appliances, like say a hand mixer. I want to add LED running lights around the joint where the top part of the case and the bottom part fit together. Of course, I also want to still be able to use the mixer for its intended purpose, so I can't just slap a wall wart on the cord. Does anyone have any hints on a safe way to divert/convert about 12v of DC power from the 120v AC power cord? Ideally, I'd like a compact solution, one that will fit inside the case of the appliance.

Topic by TeratoMarty 11 years ago  |  last reply 11 years ago


Solar Panel Messenger Bag : Current help?

I found a super cheap solar charger at goodwill and couldn't pass it up. ($2 for this thing!)  It's supposed to charge car batteries through the OBD2/EOBD plug. http://www.amazon.co.uk/ICP-06002IC10-Solar-Trickle-Charger/dp/B003IVD77Q It's rated 240mA @ 18V, 4.3W What I was wondering was, if I just lobbed off just the end of the connector to have the DC wires, and left the voltage regulator, could it power a laptop?  Through the laptop's own AC!!!!! adapter?  I recently discovered that the NES was an AC device that did fine on DC power but it's kind of a different story when it's a macbook. Or instead of through the standard adapter, straight to the laptop power port itself?  Probably after making another small current regulator to get the right voltage.  The adapter accepts AC 1.5A 100-240V 50/60Hz as input and outputs +16.5V DC 3.65A Or possibly lob off the voltage regulator on the solar panel and seeing what I can max out at?  I'm open to a lot of suggestions.  Evidently it has some sort of protection circuit to prevent overcharging the battery so I dunno if that would help or hurt this endeavor.  But having an integrated toteable power supply would be pretty neat, always charging my macbook.  Or even my DS lite or GBA SP.

Topic by stalledaction 8 years ago  |  last reply 8 years ago


Which transistor for ne555 output?

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

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


Will a 240 Volt AC Motor Operate on 120 Volts AC

I need to know if a 240 volt ac squirrel cage fan motor can be safely run on 120 volts ac. An quick internet search reveals several sources that all say no, but I am concerned that the people answering the question don't know what they are talking about - as is often the case on the internet. I know there are a lot of want-to-be engineers out there ready to answer any question posed even when they have no experience or knowledge of the issue. Please do not guess at this or offer some unsubstantiated opinion.  I need a real answer to this question. Here is what I do know about this issue from researching a couple of electrical engineering sites. Lowering the motor input voltage by 50 % does several things. 1) The motor will run slower. 2) The torque developed will drop to about 25% of its full voltage rating.  3) This decrease in torque can make the motor stall when trying to start under a heavy load. 4) There may be drastic speed fluctuations due to load variations.  5) The motor current will double if the load remains constant. I can understand how these issues could cause severe problems in some applications, but perhaps not in the application I am looking at. I want to use a squirrel cage motor rated at 1/20 HP, 240 volts, 0.5 amp in a direct drive fan application. Here is how I am looking at this issue: - I need to reduce the fan speed so the speed reduction is a good thing in my application. - I have test run the motor on 120 volts for about an hour and there is plenty of torque to operate the fan. I figure at the lower speed there is less air load on the fan blades so less torque is required. Again a good thing for this application. The is no heavy load at start up and the motor seems to have plenty of starting torque for the fan. The fan does not reach full speed as fast as it does on 240 volts, but it still does so in about 4 to 5 seconds so this shouldn't be an issue either. Since it is a fan moving air and not some machine moving gears and levers the load is constant so the speed does not fluctuate at all. Again this should not be a problem. The possibility of the motor current increasing is my only concern so far and apparently it is not an issue since a test run showed the current decreased from 0.5 amps at 240 volts to 0.4 amps at 120 volts.That is a significant current drop instead of the predicted increase. Since this is a fan, I think the current decreases because the load decreases with the lower speed. For these reasons and based on my apparently successful test run I think the motor will operate fine on the decreased voltage. However, I am not sure how to factor the motor slip into this. Slip is the difference between the synchronous and asynchronous speed of an induction motor. From what I have read the slip will increase dramatically when the voltage is cut in half, but I am not sure what physical affect that will have on the motor. If you know what effect that will have or know of some other factor I am not catching please let me know.         

Topic by biochemtronics 6 years ago  |  last reply 2 years ago


DC power drop alarm Answered

I need a very simple way to see if power is ever lost to load.  I am trying to run a long term test of at least 60 days.  I have a UPS that is powering a load and I need to be able to determine if the 12 - 15 V dc that the UPS is providing is ever lost. The UPS has a battery that will supply power if the AC input is lost.  The solution can be very simple and I really don't want the load to be reconnected if the current going to the load is ever lost. I need to know if the load is ever not powered, even for a brief instant.  I was hoping there might be some type of switch that would open if the current stopped flowing through it.  Sorry for the simplicity but I know very little about electronics.  Thanks for any help or advice.

Question by brentatespicorpdotcom 3 years ago  |  last reply 3 years ago


My TV n Cable turn off im running DC not AC?

Called the cable  company and inquired as to why my tv and cable box and other things keep turning off.  when they sent some one to check the installation they said that after checking my outlets, they said i was running a DC hot lead and that i was not on an AC type current. WTH does that mean how do i check to see what kind of current my house is using, i have had no problems in the last 25 yrs. so this does not make any sense to me.

Question by evollover6969 4 years ago  |  last reply 4 years ago


AC Switch Wiring... HELP?

I just purchased an AC lighted switch @ rs, but the wiring diagram is giving me trouble, and off the top of my head, it looks like i'll have big problems using it (without losing the lighted feature) in my current circuit... If anyone knows how to make it fit, or knows a good replacement, please help... the problem, as illustrated in the diagrams below, is that I need to wire the switch in series with the load, where as it wants the lamp to be in parallel . i only have easy access to the hot wire before reaching the load, but would like to use this switch.

Topic by gschoppe 12 years ago  |  last reply 12 years ago


Limit current to 170v 5 amps?

So... I connected 120v ac mains power to a bridge rectifier > capacitors to smoothe > switch > output... how can I prevent the breaker from...breaking.  Also the integrated bridge rectifier can only take 6 amps for long amounts of time.  I need to somehow limit current without limiting voltage (at least to much)

Question by TypeNameHere 1 year ago  |  last reply 1 year ago


How to create dc input to dc 5v, 5v, 12v (three outputs w/ diff currents)? Answered

I want to create a single power source for these three components: 1.Raspberry pi : 5v , >750mA 2. Display : 12v, 750mA needed 3. Powered USB Hub The input source should be dc max 12v...

Question by akki5230 4 years ago  |  last reply 4 years ago


how to convert ac to pure dc? Answered

I want to convert 5volt ac to 5 or less voltage! i got  a transformer it gives out 5volts dc! i used four diodes bridge ! but the current is still vibrating i came to know this by using a simple white led it vibrates! although the diode bridge converts it to dc but not in pure dc format help me!! can anyone give me a simple circuit to convert it to dc ( i have used diode bridge but it it is still vibrating i need some more out here to make it!!  )

Question by ubdussamad 6 years ago  |  last reply 6 years ago


Can I power my 9v amplifier using usb? Answered

I made a small amplifier in a design class once and it requires a 9v battery to run. I want to use it to make some LED's flash in time with music and so I would like to run the amp off usb. I thought about using a transformer or dc converter but I'm not sure whether it will give enough current to run. Could I just run it straight off usb or will the 5v not be able to powere it? I have a multimeter so if needed I could possibly use it to find out the rquired voltage and current? Please reply if you can help me with what to do. Thanks

Question by pyro-jim 9 years ago  |  last reply 3 years ago


is there a way to make an ac arc using a disposable camera? Answered

I am currently searching for a way to mod a disposable camera so it will make an ac current and in extension an arc (continious or regularily pulsing , either one is fine) for my potato launchers ignition. i have seen that a decent spark can be made by connecting to wires together connected to the capasitor, but i want it to work electronicaly , not manualy aka with a trigger what i want to know is how (if its possible) to create an arc from the disposable caremas transformer that will work straight away, or converted from the capasitors dicharge into ac current which can jump to cause ignition.

Question by oldmanbeefjerky 8 years ago  |  last reply 7 years ago


Low voltage to very high voltage transformer that can handle as high a current as possible?

I'm looking to convert roughly 5v ac to around 400v or 500v and be able to handle an enormous current. I know very little about transformers when it comes to their current limits. Any help would be appreciated.

Question by ChrisW7 3 years ago  |  last reply 3 years ago