Volts from an USB cable

I need to know how many volts a usb cable provides from a laptop. I couldnt find any information on google and I know that someone here has to know.

Posted by allstarn07 10 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 10 years ago


5 volts ballast

Can I have the circuit for the 5 volts cfl lamp ballast. Please! Thanks.

Posted by remyjovero 4 years ago


What's the best way to lower 6 volts to 5 volts?

Hey friends!  I have a question. I want to be able to use 4 AAA batteries (6v) to power an IC. The IC's max voltage is 5.5. Is there any kind of way I can use two resistors as a voltage divider to lower the voltage 1 volt or should I just use a diode(which would lower it by 1.4v)? Thanks!

Posted by HavocRC 5 years ago


Too many volts from a bike generator

I took a treadmill motor and hooked it up to an excersize bike in order to charge a 12v battery and power an audio system.  Unfortunately, it worked far better than I ever hoped and is pumping out 75v at a max pedal, 45v on an easy ride.  I've looked into various charge controllers, but they only charge batteries close to the input voltage, and step-down voltage changers take it directly down to 12v, too low to charge a 12v battery.  Any suggestions?  Thanks.

Posted by EastsidePrep 6 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


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 8 years ago


What's up with this transformer!

Hey I have a litte problem! (sorta, not yet!) So, I have one of those wall adapter things, and it says it outputs 12vDC and 1 amp. Out of curiosity, i hooked up my volt meter to it and the output was a whoppin 20 volts! Why was it 20 instead of 12 like the transformer said? This is making me worry about my other ones!

Posted by HavocRC 5 years ago


Question dealing with high volt capacitors in series

As we all know (at least most) you can get free cameras at places that recycle disposable cameras. After having my fun hooking then in parallel to attempt coil gun, or just melting holes in water-filled soda cans. But I wanted to try to hook some in series, so instead of 320V, i got 640. I know series adds up so both are fully charged to 320V, but heres my question. 1: Can they ever blow seeing that the output is 640 yet their rated 320? 2: If i discharged between then, can i have a greater chance of them exploding comparing to parallel hooked?

Posted by Killa-X 10 years ago


**HELP** PSP: battery charger **HELP**

Can I charge my psp with 6 volts (aka 4xaa) ? even though its only supposed to have 5v....Or do I have to go to the source ( what used to be radio shack in Canada ) and find a regulator. If so what little digits should be on it ? and would any of the following regulators work ? AN6541 IRL3103 ( I already have them I ripped them of of old mobos) To explain I lost my wall charger and usb charge don't work unless its on..... and the battery is dead

Posted by littlechef37 10 years ago


LED Voltage indicator

I have recently installed a solar panel in my garden to charge a 12volt 21Ah battery. I would like to show it off a bit by using a simple LED display to show it working. What I was thinking was to have a range of about 8V-25V. At the low end would be blue leds (for cold) up to red (hot) at the high end. Does anybody have any idea how I would go about getting something together. I can read circuit diagrams at a push (my Dad's the expert) and would like as much information as possible. Would it be possible to have 1 LED per volt ? Am I being simple? Would this project be self defeating in that it'd use lots of the free power I'm trying to collect? Any help anybody can give I'd be grateful to receive. Share & Enjoy. Zippy.

Posted by bunglesmate 10 years ago


HOW TO: change USB plugs for 5 volts Jacks switch-Inputs (pics)

We have a several pair of carbon fibers pads, but what happens now all of them have a USB plugs that don;t fit with the receptive Jack Plug in 5 Volts Battery This batteries with the pads work to heat blanquet. We need help, or more than this a teacher! who tell us how to take out these USB plugs, how to join their cbables, and the how to add a plug in 5 Volts Jack. If is not clear please let me know Maria

Posted by Maria SoledadD 1 year ago


need some basic help with resistors and arduino

I'm just starting an arduino uno that I got for christmas and I have almost no electronics experience. I have a breadboard that can give me 6 volts, but what type of resistor do I need to get 5 volts out of it, or is it possible to split the 5v pin on the arduino board. What I'm trying to do is recieve an input from 2 buttons. I tried searching for it on google and found nothing. Let me know if I posted in the wrong section too, because I wasn't quite sure if the Tech section is right. Thanks in advance.

Posted by Nannerman 6 years ago


Arduino Solar Capabilities

So I went and bought a 1.5 Watt 9v solar panel from radioshack today. It gets ~10.5v and ~80mA in full California sun, and ~10.2v and ~75mA in afternoon light. Does anyone have any experience with running an arduino only on solar power? If so how much load can it take at this power level?

Posted by martzsam 5 years ago


I need 9V DC what happens if I USB it?

I'm making a compact speaker enclosure that will fit in a laptop bag I've got everything together and looking sweet. making this because my ACER laptop has crappy sound and I want to be able to hear things on it when I travel. I have sick speakers at home but there very not portable. problem right now is power is supplied by a 9V DC adapter I really hav no mre room to make any other type of circuit or battery pack........its pretty tight. what happens if I just cut the adapter and put a USB end on it? I realize it will only provide 5 Volts but will it work?......... maybe just reduced power? will any damage result? I know only a little about voltage and most of my electrical experience is through trial and error. (not recomended, I've zapped myself more then a couple of times) Ideas?

Posted by chaoscampbell 10 years ago


Can I hook up power and usb cable to arduino?

Hey guys, When I'm using my arduino, (plugged into my Mac via USB) my mac just randomly shuts off. Is it because I'm pulling to much out of the USB? Can I hook up my 9v into the DC plug and hook up the USB or will combine the input and fry the board?

Posted by HavocRC 5 years ago


How do I regulate voltage on a multi-amp battery charger.

I know very little about electronics. I have a car battery charger that outputs in 12 voltsDC. It is also "switch" selectible for 2 or 10 or 50 Amps. Once I select one of these choices 2/10/50, I would like to vary the voltage up and down from 1v to 12v. How do I build something that will vary the voltage at each of these amperage levels. Thanks- Steve

Posted by st600r 1 year 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


Coil Gun Project

Hey guys, I am currently building my first coilgun, first of all, the components: Charging:     Disposable camera circuit x 2     2 x D cell batteries Capacitors:     2 x 1200uF 200V     2 x 680uF 200v     2 x 300uF 200V     1 x unknown (attached to camera circuit with no info) Switch:    250V @ 15A - 6 pole toggle (I will upgrade to some for of solid state when I have the money) Now, because I have two of each capacitor I have put one of each into a parallel bank, giving me 2 cap banks with one of each cap, I then connected the two banks in series, I have not done a lot of maths yet which I think I should but I was hoping that would give me 400v which seems to be average. The problem is, it is only charging to 340v tops, I think that may be due to the camera circuits being wired incorrectly. I have the two batteries in series, both charging both of the circuits, then the circuits both charge the caps, the + and - outputs meeting on the caps, am I doing that wrong? Also, does having 300uF caps in series with 1200uF caps hinder the bigger ones? Would I be better of with just the 1200uF and 680uF, or maybe even just the 2 1200uF in series? should I also leave the small cap on the circuit or take that off? Thanks in advance guys, any help would be greatly appreciated. I am having a lot of fun with this project and while I wouldnt like to be on the other end, it is still not as powerful as I would like, even for it's small size.

Posted by TristanD27 4 years ago


SSR and a hotplate

Dumb question. Have a heating plate that uses 1100 watts and runs on 120 volts ac. if 1100 watss / 120 volts = more or less 10amps, Could I safely use a 10 amp rated ssr aka solid state relay or use something higher.

Posted by Computothought 3 years ago


Help with wiring a 9v screen to 12v

If you are interested in what i am doing with my wii check it out ( http://www.wiinode.com/forums/index.php?showtopic=4280 ?... ) As you can see with my site i have a screen that uses 9v and i need it to be used along with the wii (so i only have to carry around ONE plug in) i have my amp wired to my wii using 5v and it works great. I need my screen to work alongside my wii. Ive tryed a 9volt battery before but some reason i get a blank screen but my ps1 7v power connector makes it light up good.when i plug 5v on the screen it leaves it very dim. There is 12v also there are alot of 5v points and some 3.3v points on the wii, could i combine them in some way to recieve my needed voltage or use the 12v? anything thats not to costly or spacey (need my smallage so i can have a small case) and please dont post about me NOT needed to do this thank you. if you need more info say so and ill update the question. I KNOW THE RISK INVOLED WITH WHAT IM DOING!please also note that pics are old. Just giving them for info purposes. Please ask me if you need any other details. :) thank youEDIT: fixed the link.

Posted by Wiimote Master 10 years ago


Step down transformer

Hi I would like to build my own power supply. i am a noob at electronics but hopefully this project will improve my skills... http://electronics-lab.com/projects/power/001/index.html This is what I want to build The problem I am not sure on is the 1st initial step of the step down transformer. I have only found a 24 volts 4.16 amps with 100va. I want to keep the project as exact as possible and was currious whether if the current rating is higher than 3 amps for that particular circuit I want to build can it blow any of the circuitry. The transformer I found was 24 volts 100 va and has an output current of 4.16 amps. Is that a problem or will it only draw as much current as needed?  

Posted by Bedawee_zeus 7 years ago


DC power logging, or at least measuring (for solar panel & devices)

I have searched and searched, but I can't seem to find what I need. I want to be able to log power and plot a V-I graph and a P-t graph. I was picturing tapping into an iphone charge cable (for example) and wiring in connections. Here, I could connect the device, so that when i connect the phone via charging usb cable, current runs through the device and is measured, and voltage is read from inlet of the device to gnd. Do these exist? I'd like to also use it for a solar panel (putting a big wire loop resistor for a load to draw max power) so that I could see where the power tops out, what voltage is yielded when the max current is drawn, etc. It would be nice to be able to plot data points in excel for example. Any idea? Even if I can't LOG the data, I'd like to be able to read instant power use, not just V and A. I've seen the inline USB meters that do that. Anything helps! Thank you!

Posted by Phoenix17 4 years ago


Running 12 volt off 240 volt

Any one have any ideas how i can (as cheaply and easily as possible) run a winch made to be ran off a 12 volt ATV battery off Australian mains(240 volts)?(this winch to be precise)Cheers, Will

Posted by willj89 11 years ago


How to get 12 volts from 18 volts

How would i regulate 18 volts(2 9v batteries) to put out 12 volts instead? im doing this because 2 6v batteries is really heavy(im replacing 2 6v batteries, and they are also broken... dont ask how) thanks

Posted by ledzep567 10 years ago


4-Pin XLR power supplies

Does anyone know what the connection pins are on those 4-Pin XLR power units commonly used for video cameras or camera mounted lights? I know it's 12V 1.2A but I'm not sure which pins are used for what (i.e. pos, neg, 0V, +12V) I want to turn a normal adapter into one with a 4Pin XLR connector to be used with a camera light.

Posted by mrshow555 10 years ago


12v car fan motor for an electric bike

Hi everyone ! I have a project for school that's called "the no project project". I have to do anything I want... so I had the idea of doing an electric bike, or tricycle. So I searched for motors... chainsaw motors... etc ! I have a little budget, and I red it was possible to use car heater fan motor, so I was very interested! But I wanted to have a confirmation from you guys... is a car heater fan motor as powerful as a wheel hub motor? and it is possible to use them as a electric bike motor? Thanks !

Posted by Antoto 8 years ago


100 volt ac motor

I have a Sony 100 volt AC motor and would like to use it with 120 volts.  Can anyone give me some advise? The motor came out of a Sony tape recorder.

Posted by ecafighter 4 years ago


Exploding 9-volt Batteries?

I have always wondered if 2 9-volt batteries connected pos. to neg. and neg. to pos. will it explode? Look at the picture if you need help understanding what I mean.

Posted by Thelonelysandwitch 9 years ago


how to keep 3 volt instead of going up to 6 volt

Hi, i have a honda camino , i want to make a rear light. first how do i get the 3.0 volt staying on 3 volt ac and what do i have to do if i use four bright white led in parallel,i have to have 5 watt in total.

Posted by alex4421 11 years ago


electrical/electronic

20 amps transformer of 14-0-14 volts from 220 volts bobbin size? primary gauge,turns? secondary gauge,turns thanks.

Posted by imamfarid 4 years ago


6-Volt Lamp

I have this 6-volt Lamp it's kind like what you would find in one those 6-volt flash lights except that this is like a stand alone lamp and it has two wires that come out of it but only seems to work at 6-volts, so I have a large 6-volt battery and a 7.5 volt output power adapter I was wondering if 7.5 volts would be too much power to use to power the lamp I don't want to blow it up. I don't know if it'll even work at 7.5 volts because I tried a 9-volt battery and it won't power on with it.  The image is the same lamp I have except mine is connected to a base and has two wires that come out the bottom I would like to find another way to power it besides using a large 6-volt Battery.  Any Suggestions.

Posted by Graydant 3 years ago


How to power an MP3 Player with 6 Volt DC Motorcycle Battery

Hello, I am creating an audio billboard, you all have seen billboards with words, this is a billboard, but there it also talks to you. WHY? Because I am here in Kara, Togo West Africa. In this village they speak 3 local language, and if very educated, they speak French, but if you really wanted them to listen, you would talk in Kabye. I would like to offer free Malaria medicine to people, and this could save babies from dying, 1 in 10 dies that has the Malaria parasite. Mothers avoid going the lab, or taking the cure because it cost one weeks pay, about 7-10 dollars. The longer they delay, the more likely the baby is too weak, and dies. The need to know, money is the problem, but how to tell them, this audio box is to tell them money is there in their own language. But to make it work for one-month, or one year without maintenance is the challenge. I am will experiment with the device inside a Hotel signs, and try to have the Hotel help, they get an ad, and the public ad is served, help them, and they help. The electricity goes off between 3 and 10 hours, sometimes more in Africa, about 200 countries and this box is not close to electricity lines, but next to water pick up spots.  I want to power a 6 Volt Radio I can buy here in Togo, West Africa with a 6 volt motorcycle battery. I am hoping to have the radio run for 10 days, 24/ 7. I can buy a 6 volt motorcycle battery easy, and can even charge it by connecting to a running cycle with alligator clips. But, I need to figure out the correct way to set this up. I learned today, I cannot buy a 6 volt battery charger here: - So I put a diagram down below showing how to make one? Is there a way to know when the thing is fully  charged? http://www.alpharubicon.com/elect/3dollarbattggn.htm What is needed to connect the battery the radio? - I put a wiring diagram with a fuse and diode, is this correct? This is a French speaking country, I speak ok French, but not the word needed to make this device. I need help. Andy Graham of HoboTraveler.com in Kara, Togo West Africa. Thanks

Posted by hobotraveler 5 years ago


120 volt flasher circut

I need some help finding a way to flash a 120 volt incandescent light bulb. Im looking for a way and have found close to nothing. if any one can help, thank you

Posted by newwarhammer2 6 years ago


LED Questions

Help, I'm afflicted with inspiration in quantities that exceed my skills!So I came up with an idea for a project that would probably require the use of LEDs, which I know next to nothing about. Ah, said I, the Internet can teach me much... so I turned here and found the (nearly) perfect Instructable, "LEDs for Beginners":https://www.instructables.com/id/LEDs-for-Beginners/Having read this most helpful I'ble, I certainly came away more knowledge than I'd previously had, but still not enough to properly plan my project.Basically, I'd like to create a 2D "array" of LEDs to use as a light source, in order to backlight a roughly 8.5" x 11" translucent panel.It seems like it would be straightforward to just wire up a bunch of white LEDs in series to a power source and a resistor, and be done. I'm not afraid of a little trial-and-error, but I prefer to know at least roughly what I'm doing going in, so I'm asking for your help. Here are my lingering questions:1. Should I wire my LEDs in series, or in parallel? (Or some combination thereof)? In series, I gather that one LED failing will break the whole circuit, which could be a pain. On the other hand, I've seen several projects and sites that cryptically recommend against wiring these in parallel.2. Are there pre-built strips of LEDs I could acquire that would make this project simpler?3. If I want to vary the brightness of my light source, can I use a variable resistor (potentiometer), or does the nature of the LEDs preclude the use of this type of dimmer switch? If so, could I vary the brightness with multiple switched circuits, turning off half the LEDs for half brightness, 3/4 off for quarter-brightness, etc?4. I've got a slew of transformers from old tape decks, telephones, cell phone chargers, etc. Can I appropriate one of these as my DC power supply?5. How do I gauge how many LEDs I'll need, and what density is best to lay them out? I'm looking to create even, diffuse light, with no noticible bright/dark spots.6. Do I need to worry about heat?7. Are LEDs even the correct way to go here? Should I consider fluorescent light instead?I realize these are a lot of questions, but if you're an expert on LED projects, you could save me a lot of research time. If (I build this gadget, it will definitely show up here as its own Instructable.)Thanks!-JD

Posted by jdtwelve12 9 years ago


nichrome wire

I got some nichrome wire off eBay, and it works great but when I connected it to a 9 volt battery it barley got hot, then I attached it to 4 x AA batteries and it got red hot. why is this? I don't understand because the 9 volt gives out 9 volts(duh) , but the 4x AA batteries only gives out 6 volts.

Posted by Jordo 10 years ago


resistors

How many ohm resistor would i need to resist 7 volts to 3.5 volts and 12 volts to 3.5 volts also....

Posted by Yerboogieman 11 years ago


Volt conversion with mobile charger ?

Hi, I have to DC device  a) works with 5.V    (b) 1.5 Volt...  I am using mobile charger as a power supply.  How can i connect them with one mobile charger....as the charger output is 5.V  only.  a) works fine but as the other device require 1.5 Volts . Which type of power  component should i use to supply additional appox. 1.5 Volts ? will any of these can device blast ? Any type of tips n tricks will be very help full. Thanks, Richi

Posted by RichiV 3 years ago


3-6 volt ac to 12 v dc

Hi, i going to give it a new try, i have a power source of 3-6volt ac , an di want to get 12 volt dc,and i want it to stay 12 volt dc ,if my input is between 2.5 and 6.5 volts.ac

Posted by alex4421 11 years ago


Making a better spot welder....

I am in the process of building a proper spot welder from scratch. Proper more in terms of the electrical and electronics part but not so much in looks ;) My problem now is to find useful info on what power levels are required for certain tasks. I realise that welding thin sheet metal won't need as much time and amps as welding a 3mm stainless steel rod - but what is a "good" power level? I watched a bunch of Youtube videos showing various approaches but for many it seems the producer had no clue about the difference between creating a short with burn marks and a weld... Especially when it comes to creating battery packs with a capacitor bank as the main power provider you can clearly see the device burns holes but does not really create a welded spot. On the other hand there are a few videos showing spot welder made from a MOT that seem to produce a proper melted and welded connection. When I used a proper spot welder at work it had timing settings, power levels and even a feature to adjust how the current rises.... Not to mention a gauge that checks the pressure and only activates the welder once the set point is reached... There is a ton of info out there that after a thausand words still tells you nothing you need to know :( So is there anyone here who can shed some light on the actual process of spot welding in easy words for everyone to follow? I am aiming for a max output of around 400A @ 1.5 -2.5V with an adjustable shunt in the transformer core to avoid oversaturating the core. In a later stage I will add power control over the primary side but until then it is only time control, from a few ms to a max of 5sec if the damn controller arrives one day. Big questions: 1. Is a power control really required or is it possible to cater from thin to thick just by using different timing settings? 2. Since a MOT is used for the power supply: Is it better to leave the shunts out to fully avoid saturation by adding an inductor in line with the primary or is it still better to adjust the shunts under load to get the maximum power possible? 3. Aluminium and other materials benefit from using AC but would be good to have a DC output too, if so then what materials really need DC? 4. All I could find is that copper is used for the electrodes, due to resistance and heat transfer - are there other options apart from using copper? 5. Tricky one: I would prefer to use the secondary winding as the new primary to avoid core saturation and to lower the load on the power outlet. Where can I find very thin copper bar material that I can coil up and insulate as I would quite a few more turns to get at least 1.5V out of it? Just don't like the idea of spending days rolling a copper bar thin enough.... For the advanced model at a much later stage: Of course I would like to be able to use a proper power control instead of a motor dimmer or similar. For obvious reasons an inverter microwave jumps to mind. But after checking one I noticed one big problem: there are not really that many windings on the primary of the transformer at all! Same way our modern switchmode power supplies only use a few turns these things do exactly the same. After some quick and dirty initial tests I realised that even a single turn of thick wire already results in over 20V on the secondary. Wasted a lot of wire and time making one coil with 5 turns less and one with 10 turns less but the system would not even start with it. Seems these things need a fixed inductivity on the primary that matches the frequency used, in my case 36kHz. Would love to overcome this problem so I can at least go down to a single turn to get under 5V on the output side as space is non existing on these inverters. Can I cheat? Do I need to change the circuit to match the new primary coil? Am I thinking in the wrong direction altogether here? And added bonus would be to be able to adjust the power from around 15% to 100%, so far the electronics don't allow anything below 45%. Is it possible to drive these inverters in resonance? (Ok, off topic as I would like to use this for a beefy HV supply) Last thoughts: I know people already used Arduinos and Raspberries with displays and all but so far I have not found anything that shows how to do it properly. Seems all that counts is to create connection one way or the other and to call it a spot weld even if it is just a burn hole from discharging a capacitor bank through a needle like electrode.... For obvious reasons I don't want to create just another spot welder that makes a professional pee himself laughing about it. IMHO nothing beats personal experience with something but I don't really like wasting my time by trying what other people alread did a long time ago. So if YOU already built a MOT based spot welder and used for more than a few spots I would love to hear from you! Let me know what type you used, what problems or shortcomings you noticed or where you feel it just does not work out the way you expected it. From simple things like always getting bad sparks or arcing, over how easy or hard it is to get consistand results to whatever really annoys you while using your homemade spot welder. I hope that your feedback here will help me to write an Instructable on building a spot welder that does what you expect it to do, not once or twice, but everytime you use it. Mechanics might vary the same way the electrode style does but the weld should always be a proper weld that won't tear apart ;)

Posted by Downunder35m 8 months ago


How to Re-route 9 Volt Batterie from Smoke Detector

Hello, We have 14 feet high ceilings and smoke detectors in 4 rooms at that height. Not wanting to crawl up the ladder to switch the 9 Volt batteries, one would think you could simplify this task. Use a 9 volt battery connector to connect to the battery ports in the smoke detectors, a wire each to a central point in the house, such as a hall closet, where each wire ends in a 9 volt battery box. I can find various 9 volt battery connectors to purchase, have umpteen yards of low voltage wire (from sprinkler system installation). What I don't know is, is there a limitation on the length of wire I can have a 9 volt battery on one end, and the smoke detector on the other end? Thank you. Stefan

Posted by StefanGH 4 years ago


tech

In 12 volts 3 ampere battery, how many 12 volts led can i use to light it up(not a strip one)

Posted by xandera 4 years ago


LED tail lights for a 6 volt Car

I have a 1964 Volkswagen beetle, the car still has its 6 volt electrical system, meaning all the lights are very dim. I would like to use multiple LED's in each tail light housing in order to make brighter tail and brake lights. Can this be done without converting the car to 12 volt ?

Posted by Woody4 6 years ago


What's a good use for Size A (3.6 volt) battery?

Looking for the best idea on how to use my Lithium Batteries, Size A (3.6 volt) with positive and negative leads.  Be creative, be practical, this could be fun.

Posted by tonilynn 7 years ago


How to build a 12 volt to 1.5, Volt DC/DC Converter

Greetings all.  I suspect this is a pretty remedial question but I've not been able to find help or instructions online...so here I am.  Basically I want to build my own 12V to 1.5V converter to power a small electronic device in may car that is currently chewing through a lot of batteries.  Such converters are cheaply available online but what would the fun of buying one be, if I could make my own instead?!  Can anyone help me get started by pointing me to an online resource with information on how to make such a device? Many thanks

Posted by mcbenney 8 years ago


HELP!!!

I want help making an old microwave clock hookup to a 9 volt battery for power... Any ideas???

Posted by xxemofriendxx 9 years ago


Supercapacitor Voltage Draw

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

Posted by merlinj 2 years ago


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


Solar charge circuit question

Hi, I have a 12 volt / 0.5 watt solar cell and I am hoping to charge a 9 volt / 200 mAh rechargeable battery with it. I think I have a suitable diagram for the circuit here... http://www.flickr.com/photos/oskay/2963306721/ I was wondering if using a 12 volt cell was ok for charging the 9 volt battery? Would I need to add resistance to the solar cell to bring it down to 9 volts? If so where would I add the resister to that diagram? If it's relevant, the load will be a fan. Thanks.

Posted by horsebones 7 years ago


Relay Schematic

I have a 1 volt signal that I need to latch open a 12 volt circuit for about a minute. Does anyone have a schematic?  

Posted by Divet 6 years ago