How can I get the MilliAmps lower on a adjustable power adapter?

Im looking to power a 12V 200mm Fan with a adjustable power adapter which is set to 12V DC. The thing is the fan only needs 0.16mA "Milli Amps" while the adapter gives 0.5 How can I lower this physically?Maybe open the adapter and break some things replace then etc etc. Thanks

Asked by Cartman007 8 years ago


how do i lower the milliamps in my adjustable adaptor?

Hi it seems i need to lower the milliamps, currently at 1500, in my adjustable adaptor in order to run a small dc motor that usually runs with a rechargeable 2.6v battery. i think the ohm rating was 006.5 but im not sure. im trying to test these motors without having to bother to charge up loads of batteries all the bloody time. but i cant test them accurately as the motors run alot faster when plugged into the mains using the adaptor. what do you think is the best solution?

Asked by jbasham1 5 years ago


How to increase amps?

I heard ampere could be increased by capacitor. If true then how to do it???

Asked by simba1 3 years ago



Battery has lost amps?

I have used a 12v 7aH lead acid battery to power a small amp and speakers, yet recently the battery doesnt produce enough amps for the amplifier (3A). What could this be down to, and is there anyway to fix it? Thanks.

Asked by finnlay 8 years ago


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

Posted by TheLostAmish 9 years ago


can stepper motors be combined to double the amps?

I have four stepper motors connected in series to get 12v and more . Can I connect them differently for getting higher amps I think they currently put out like 30 ma each is there a way to increase this amp? thanks for sharing Al

Asked by celalboz 8 years ago


Amps

Say, I thought I'd ask seeing as I got a little extra money to burn from christmas, anyone got any old/unused car amps they might want to sell to moi? My current sub amp is ever increasingly scaring me and my sub sound's like it's blown a voice coil or something (although I know if it were blown it wouldn't be working as good as it is). What do you got to say Nachomama?

Posted by Punkguyta 10 years ago


How to change old speakers into amp.

Help! I've got a pair of JVC 5-way speakers that I'm trying to power with a Danelectro E-studio 9V headphone amp for my guitar. I've been successful using it to power some old walkman type two way speakers by just plugging into the headphone port. The JVC's will take up to 400 watts. I made a small port 1/8 plug but to no avail. Any ideas?

Asked by 9 years ago



How many Ah are car batteries?

I want to know how many Amp hours a car battery has? I need to know how long I can use them for particular things. Also how many Amps will you be able to draw from a moderate sized one? I need to know how much I can squeeze out of them before I start experimenting with them.

Asked by The MadScientist 7 years ago



12v DC battery amp measurement? Answered

HI, I have a 12v dc battery and I wanted to measure the amps. Can anyone show me how to hook up the multimeter? Thanks

Asked by amantux 6 years ago


Not getting an amp reading from panel?

I am a newbie, I built a panel and I am able to get the voltage but I am not able to get a reading for amps.  Any help will be greatly appreciated. Natalie

Asked by Kumachun 8 years ago


When to use solar cells w/ 5 to 8 amps vs. cells with 3.5 amps?

What are the ups and downs of using solar cells with higher amps like 5 or 8amps does it all break down to use of space? Do you have any examples for me?

Asked by golfdeals 8 years ago


Battery power

I am attempting to calculate my amp need for my garage in order to set up a 12v battery system. Using the formula; Watts / voltage = amps drawn, I have hit a question. If using a 12v battery system and converting to 110v, should I be using 12v or 110v in the formula?Example; 100 watt light bulb / 110 volts = .91 amps. Nice!But if I use the 12v; 100watt light / 12v = 8.3 amps.I'm believing I would be drawing 8.3 amps from the battery to power this light.Plus the converter draw...Please tell me which is correct?

Posted by olddawg 10 years ago


Do you add amps together? Answered

I guess I don't understand how amp ratings work. I want to use a 12v 5a power supply for a peltier plate. I am using a 2" cpu heatsink with a small fan attached to cool it properly. I tried it with a 9v battery and it worked but I want to use an AC to DC wall psu. The fan is 12v 0.12a. Do you add the amps together (5.12a) for the total? If so, does that mean a 5a psu is not enough? I don't want it to be too low and draw too many amps and damage something.

Asked by Arya42 3 years ago


Amps

Can anyone tell me what happens if you take two 1.2v, 1900mAh  rechargeable batteries in parallel connected to an LED?  Does it increase the amount of time the LED will stay on?   I'm new to this.  Working with small solar charging lamps.  Thanks Patty

Posted by PattyCA 2 years ago


how much current needed for a bilc pump to operate, will it operate with say 2 amps 12v PSU? Answered

How much current needed for a bilc pump to operate, will it operate with say 2 amps 12v PSU? I have this pump, i can barely spin it by hand and it is not working by poering by a 1 amp psu, perhaps I demaged it while testing with 24v Ac . thanks

Asked by celalboz 8 years ago


Tiny circuit to measure amps?

I am going to use a ATTiny43U to obtain the voltage of a 2vdc solar battery, via self powering (0.8-5.5VDC). Using ohms law I know I can obtain the amps as I will have the voltage and a resistor. I want to know what resistor to use? I will feed the amps result back into the ATTiny43U as well as the temperature from another sensor. Can someone please advise me what tiny circuit I can use to get the amps as I do not know what size resistor to use? The operating voltage should be between 1.55 and 2.67 vdc give or take a bit. Thanks and kind regards, jB

Asked by britesc 5 years ago


Can anyone tell me step by step instruction on how to convert an old phonograph tube amp to a guitar amp.

Can anyone tell me step by step instruction on how to convert an old phonograph tube amp to a guitar amp. It has a 6bq5 power tube 6X4 rectifier tube, and a 12aX7 pre tube. Can anybody please tell me how to do this. You would be so appreciated. I have soldering skills, but not too much electrical knowledge. I know what resisters are, I know what transformers are, I know what capacitors are, and I know the very basics of their functions, but I can't understand how to tear it down and make it a good guitar amp. I want to remove the feedback circuit so that it will distort naturally. I would also like to modify the equalization and tone to better suit guitar amp. Please help. You would make me so happy. I cant afford to buy a good tube amp, and this is my only hope of making a great sounding amp. Thanks so much. Please be as detailed as posible in these step by step directions. You are awesome if you can help me.? Thanks The amp is from a 1959 Newcomb model R124V phonograph with an inboard 6"X9" speaker. It works perfectly with no crackling knobs or nothing like that. The amp is super clean and well cared for The tubes inside are 6BQ5 FROM AMPEREX BUGLE BOY. The rectifier tube is 6X4 from sylvania, made in USA. The 12AX7 is made in Britain, but I can't see a name on it. I have many spare 12ax7's lying around though. Thanks so much in advance.

Asked by meman-mark 6 years ago


how to run 2 amplifiers in stereo?

Hello,I have 2 marshall jcm 800 amps and 2 4x12 cabinets,how do you hook them up so it will be in stereo? I have the stereo cabinets.thanks!

Asked by bones777 9 years ago


Can anyone help with making an amplifier?

I want to drive two front speakers (200 watts each) and a subwoofer (has its own amp) i would have two inputs(computer and Xbox 360). I would like to be able to switch between the inputs easily and control the volume. I could buy an amp already made up but to get the power i want there would be a number of wasted features and i would like to keep the circuitry and boxes to a minimum. If anyone could help or has any ideas i'd appreciate it?

Asked by sutek 8 years ago


URGENT! Question about in-line audio control between amp and speakers? Answered

I have a unique project that I am almost finished with, but need to make one last adjustment to. I am running a 3.7W Class D Audio Amplifier. The amp has two outputs. I need one to run as designed (controlled by my iphone before the signal gets to the amp which will be set to almost max volume). I need to then control the other output channel to reduce the volume. Any suggestions? It seems like I might be able to just get an inline control out of an old set of earphones, but I am not entirely sure. I always assumed (and pardon my ignorance if this was a foolish assumption) that the buttons in my iphone earbuds actually signal the phone to change the volume, and isn't really "in-line". So, I don't think those would work. Would an old set from Goodwill work for this? I have seen posts where others are asking similar questions and the answer seems to be a 1K Ohm Pot (which are apparently really tough to find). Since I have a 3.7W amp, perhaps a 10K Ohm Pot will work (people have said this doesn't work well for their headphones).  To summarize: 1) Will adjusting one output channel on a two-channel amp work? (or will the increased resistance simply close off the channel and pump all the signal to the other channel?) 2) If this will work, can I use a 10K Pot? 3) If not, will an old-school in-line volume control from some headphones work? Sorry for all the info...trying to be thorough! Thanks a ton for any advice!

Asked by WhiteTyrone 3 years ago


Relationship between volts and amps

I'm working on a project found in this thread https://www.instructables.com/community/Solar-powered-cell-phone-charger-case-hack/ I think I'm almost ready to buy parts and start building but I have a small issue with getting the exact voltage and amperage output I need. I've been researching for hours and I can't find a simple answer to this problem. As I understand it, as voltage decreases, amperage increases to compensate and maintain wattage. Working on this basic understanding I've come up with this model. If I have a solar array consisting of 6 PV cells (1.5V 50mA ea) wired together I get 9V and 300mA. This is too much voltage and is on the low end of amps I want. If my math (and understanding of the subject) is correct, then if I use a 5V voltage regulator I will have a final max output of 5V and 433.3 mA which is right about perfect. Am I doing this right or is there more to it, like how I'm wiring the cells together? Am I correct in the idea that using a voltage regulator will increase my amp output? I'm not schooled in electricity in any way so I would appreciate any help I can get on this in as simple of a form as possible. Everything here I've put together from several hours of studying sites on solar DYI and electricity. Thanks. For reference, these are the solar cells I was referring to: http://cgi.ebay.com/High-Efficiency-Solar-Cell-32-22mm-1-5V-50mA-0-075W-/320541888508?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item4aa1c90ffc#ht_2428wt_1148 *EDIT* Below is a diagram of what I suspect may give me a 5V/490mAh output which would be absolutely perfect. I need to know if I can wire two different sizes of solar cells together in this manner and how it will effect the output.

Posted by HittingSmoke 7 years ago


My Amps! My Amps! *Screams an old crazy man in the deli section*

Yes yes, shhh I want to ask a serious question today. I traded one of my kenwood amps for my parents as their sony surround unit is really shitting out and the sound sounds terrible and the entire control panel on the front is messed up. I just want to know a couple things about the sony to see if I can fix something. The panel, well that's quite interesting to explain and if I posted a video of it you guys would probably think I edited it or something. So imagine this, the bass + and - buttons are beside the treble + and -, two sets of buttons. If you push one of the bass adjustment buttons, it glitches and turns the treble for example, up or down randomly and doesn't do what I wanted it to do. It's like this with all of the buttons and seemed to have happened after we moved here. And I know it didn't get banged around because it was transported in the back seat of a car on blankets to the new house and carefully carried in by me. If I say try to use one of the surround sound adjustment buttons it glitches out and acts like I hit another one that's beside it in any direction. Hard to explain but I'm just damn confused as to why it suddenly happend (dry solder connections?). Damn this post is long and it's only half done...lol. Bad sound, I will not tolerate it under my household, but on the other hand it was a $400 unit back 5 or so years ago and I KNOW it used to sound good, with a such a profound richness of bass that just punched right through you. Now it sounds like shit, the sound is garbled, distorted when turned up, it's not really noticeable until you turn it up fairly loud. I have/had my technics tower speakers hooked up to it and they sounded like shit when I turned them up, yet on my kenwood they sing like the wedding singer days. Any ideas nachomoma? I'll add another note that for most of it's life it's been hooked up to a pair of 250 watt (peak) optimus floor speakers and whenever we played it, it got HORRIBLY hot and warped the top a bit when it was on, enough to push it in and make it spring back up again with quite a force. I liked this receiver a lot and would like to use it again, but I don't know where all these "degradations" came from and despite my useless amount of amp questions/bickering's about I would really appreciate any ideas from you guys. Thanks.. -Punk

Posted by Punkguyta 10 years ago


How do I know where to connect the different parts of a stereo tube amp, you know the volume control RCA jacks etc ?

I am a beginner and I bought a Diy kit, I was told but when I got the PCBA and schematic I wasn't sure where to connect the volume (pot), the input or the output RCA jacks, the power supply and lastly the output transformers. I told the seller that I was a beginner and he said that his schematic was very detailed. Well I thought it was have the connections marked or something or at least have notes written on it . I an enclosing the schematic , I have even been learning how to read a schematic and all of the symbols. But I'm still lost. HELP!!!!!

Asked by LASOUND 9 years ago


Tiny 12v motor burns out a transformer. Why?

I connected a tiny little motor (12 volts, 60 milliamps) to a 12 volt, 1000 milliamp wall wart transformer.  The motor turned (no load), but when I disconnected it after not more than 10 seconds, I noticed a burnt smell and the transformer no longer has any output.  What happened?  Bad luck, or is there something about a motor's inductive load that would be incompatible with that kind of transformer?

Posted by walter.warren1 3 years ago


Slightly larger LED project.

Ok, so to start off I have done a few very small led projects before. And for some reason I decided I was going to up the concepts and baptismal by fire. Well to say the least I have a few questions. So all that read and help thanks! The Project:I have included a picture in very horrid crayola color to show you kind of what I am trying for. Essentially I am making a 6ft x 4ft robot head. I have built a frame (the picture) and there is going to be a spandex (or screen depending on what I decide) canvas with the bots head on it. What I want to happen is when I press the button (momentary contact) on the controller it activates the appropriate leds that light up a box. I will have at most 5-6 buttons pressed at once. Simple enough. The squares are going to have 18, 3mm leds. The colors are shown in the pic. I know that different colors require different volt, thus different resisters. The eyes are going to have 2 sets of 18 leds for alternating colors. There will also be 2 outside sets of lights to shine upon the face (18 leds also). "The Questions:"Well other than just asking HOW THE WHAT? I'm going to have this (or at least I want it to be) powered by one source. Maybe a 12v AC adapter. The problem is, is this enough? How many amps do I need to power 218 leds? I guess what I am saying is I know the basics but I need help with the electrical rating part of all this.

Posted by Foreverhex 8 years ago


i have an old guitar amp, what should i do with it?

Null, by old i dont mean "old" it is a newer amp but i just dont use it i meant what cool stuff could i do to it?

Asked by 7xsevenx7 9 years ago


Is a transitor the same thing as a tube found in guitar amps?

If it is, could I use a tube in place of the transitor in a simple transitor amp circuit?  I am trying to build some tube amps...  I have built many transitor amps but I just can find that tube sound...  I want to also know as the most simple tube amp circuit.  I like to start with easy and simple and then experiment...   Any advice on tubes?  Thanks...

Asked by rickonicko 8 years ago


amps vs milliamps ?

I have a ac/dc adapter with an output of 24V - 400mA. I am looking at a new adapter with an output of 24V - 1A. Will this damage the charger or battery? Thank u

Asked by Mike07512 8 years ago


Sending more than rated amps through a switch?

I know that if you use a switch or a relay and send more amps through it than rated, it can cause the contacts in the switch to melt. My question is what if you only open and close the switch when the amps being sent is less than the rated max and then send more than the rated amps but don't touch the switch? Will this still cause the contacts to melt/explode the switch? I'm asking because I currently have a circuit that works as described above and the switch still works even after many uses. Is this because I only operate the switch when the amps are less than the rated max for the switch or is the switch going to die soon?  Thanks in advance :)

Asked by WilfredS3 2 years ago


Aurora 9 bar Kit & Custom PCB for Sell

Aurora 9 bar Kit and PCB are now available for sell. ******* Prices are reduced ******* Aurora 9 bar custom PCB price is $7.50 + $2 shipping for US address. The kit is also available at $25 + $5 shipping for US address. All parts except Molex connectors and power supply are included. Kit Contents (as pictured) 16x 120 Ohm (0603) 21x 1k Ohm (0603) 1x 10k Ohm (0603) 2x 1uF (0603) 1x 10uF (1206) 1x AP7333-33 or AP7313-33 (3.3V linear voltage regulator) 3x MMBT2907A or equivalent PNP transistor 12x MMBT2222A or equivalent NPN transistor 1x PIC24F08KA101 (SSOP) 10x 5mm Tricolor LED (common-cathode) 1x 5-way Tactile Switch Notes The PIC microcontroller is not pre-programmed. You need your own programmer to program the PIC microcontroller. The kit is also available with water clear LEDs instead of diffused type shown. Please specify if you want water clear LEDs (Special: $1 less for the water clear LEDs). The kit comes with one extra LED. Power connection cable (see the picture) - optional is available at $2 extra. (International shipping is $17) To place an order, please go to my blog page - http://www.theledart.com/blog/archives/233. You will find purchase buttons. Please view my Instructable for the detailed information on Aurora 9 bar. Contact me if you have any questions. <br>

Posted by ledartist 6 years ago


boost volts deflate amps? Answered

I recently came to know about a "mintyboost" from "steveastrouk"( a very helpful and trusted member of instructables).It boosts up volts while bringing down amps very much like a step up transformer.Well I've got 2 AA rechargeable batteries rated 1.2 volts and 1900mAh.So here's my first question-I connect these batteries in parallel and they give out a total of 2.4 volts okay fine....but what about the amps?will they get added up like volts and produce 3800mAh current?The latter part-I need to boost this 2.4 volts to 5 volts by bringing down the amps(any value is fine as long as its above 0.7 Amps).Could you please give me a specificated instruction on how to do this?If to use a "mintyboost"what software should I use to calculate the required values and......... the rest...... Pls don't think I'm lazy.I really want to do this so badly...

Asked by Adarsh_tronix 5 years ago


how do i put a pick up in my ukulele?

I want 2 make my ukulele able to come up on my amp

Asked by jesse8fox1 9 years ago


Power supply volt/amp question?

Hi, My power supply is ac 110v to dc14V 700ma and I want to connect in parallel 2 strips of 4 led (350ma - 3.2v each)  Total voltage per strip 12.8v with 350ma each. I would like to power these leds at 2.5v each (total 10v)  and at around 250ma each. I installed a buck converter at the output of the power supply to reduce voltage at 10v. Will the amps also drop as voltage is reduced or will it stay at 350ma on each strip?  If it does not drop, how could I reduce amps to about 250-275ma? Thanks

Posted by Lion_Heart 3 years ago


Headphone Amp For Laptop DJ

I use my laptop to play music...(using virtual dj software)....splitting the jack .. the volume from headphone is ok when playing small system.... big system the headphone volume is low....i need more ..i buy a volume switch (B5k) thinking that will solve the problem  ..but when i connect it and turn it up its the same volume i get as if i just connect it without... QUESTION can i add any thing to this to make the headphone louder..without using any external power source 6v,12v battery etc

Posted by hitek 6 years ago


I am building a huge boom box but i am a little confused on how everything is going to wire together?

Hey, could i use this amp http://www.parts-express.com/pe/pshowdetl.cfm?&Partnumber=320-307&scqty=1, to power 4-6 speakers. Then also this http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-176 for the sound controls, i would then be hooking up my ipod with an aux cable. I am going to power it with a power cable, maybe a battery. My other question is can i hook up a more powerful 600W x 1 channel amp to a sub and have both amps play off the same aux cord? I haven't really worked much yet with home audio, just in my car but thanks for the help.

Asked by maddan417 6 years ago



Will a battery power a short LED light strip drawing 3 amps?

I am building a lighted mirror attached to a pole for conducting searches in tight places.  I have an 8.5" convex mirror which results in just over 25" of circumfrence.  I would like to use the LED light strip linked below to provide light to the area being searched and would like for it to be run off a battery source to make it easily manueverable.  I plan on using 2 ft of the LED rope.  The product specs indicate it should draw 3.0 amps.  Would a AA/series of AA batteries (or another small battery) power this light strip if wired into a switch and a battery pack? http://www.environmentallights.com/Waterproof-Dimmable-Super-Flat-LED-Rope-Light-with-5050-LEDs-60-m-by-the-metric-foot-11-8-inches-300-mm-24-VDC-Daylight-White_P3821.aspx Thanks.

Asked by flohrstw 5 years ago


How do I drive a Peltier Cooling Plate with USB power? Answered

I just ordered some of these 20mm x 20mm Peltier Cooling Plates and would like to power them with a USB hub. Their rated at max of 4 amps and a max 3.8 volts and I know that generally USB is 5V and 500mA. So I know I need to just reduce the voltage, but I'm not sure how to accomplish this. I think I could drive them at 3.5V and still be okay, Not sure if I need a voltage regulator or if just resistors would do the trick. Thank you Kurt

Asked by KurtRoesener 3 years ago


Arduino maximum current draw? Answered

What would the maximum current draw through an Arduino be? (ATMEGA328) - I'm planning on running 16 LEDs from it and I need to know if I should be powering them separately somehow.I have the appropriate resistors (100ohm and 180ohm LED dependent).

Asked by jonrb 5 years ago


How can I make a 9 volt shocker?

Okay.I want to build a shocker with a nine volt battery.No soldering iron.I have lots of 9 volt batteries. Note:A 9 volt shock is wanted .Not 300 volts. Thanks,bylerfamily

Asked by bylerfamily 9 years ago


Can a 14V 3A power supply be modified to supply 14V and 5A?

I ordered the power supply thinking that 14V and 3A would be enough to convert my dead power tool batteries into a corded solution. It's a Target brand set so I couldn't find specs on current I just knew the battery voltage.  I think stepping it up to 5A will do the trick. Can i hack the power supply to do that?

Asked by mikemorana 5 years ago


Is it possible to convert a solid state amp to a tube amp?

 Is it possible to convert a solid state amp to a tube amp?

Asked by adamgillies 8 years ago


Weeding with Style

Not bad. <br>

Posted by AngryRedhead 6 years ago


Limiting Amps on My power supply

I have a PSU that is capable of 45 amps, but I only need 10 amps. How to I limit the amps? I am using the psu to make chlorate.

Posted by tylerb 10 years ago


What's up with Amps, voltage and current?

So I'm having trouble finding out where amps come in. Typical batteries (AAA,AA,9v,3v) don't say the output amps, just output voltage. But things like RC batteries, and wall transformers have a specific amperage output. So say my LED and 9v battery. I know I need to use a 150 ohm resistor. Since resistors limit current, then is there still 9v going to my LED its just the amps/current that being lowered before going into the LED? If resistors limit current, or in its unit of measure, amps, then my LED is still getting the supplied voltage just a lowered amperage?  How do I know how many amps my projects are drawing? How will I know if my DC wall transformer with 12vDC and 1 ma isn't going to fry my circuit? How would I know if 1 amp is too much or not enough for any my circuit? Please help, none of this makes sense, ~electricloser  

Posted by HavocRC 5 years ago


Do Amps matter?!?

Ok, I need a charger for my motorolla two way radios. I have the dock, only need a DC power supply. on one of them it states "18Volts DC +/- 20%, 15.3 watts" .Lets say I get 18VDC 1amp power supply, that's 18W,it means it's an overkill? or 15V 2Amps? As I understand, usually amps don't matter, as the item draws as much as it needs, but since it is a charger.. Cheers for the teh help!

Asked by zhgutas 6 years ago