9v to 3v

Hey, I need to know how to turn 9v into 3v can anyone help? Thanks, Cory

Posted by Flumesoft 10 years ago  |  last reply 10 years ago

9v shocker

Hey everybody. First, take a look at this question's best answer - https://www.instructables.com/answers/How-can-I-make-a-9-volt-shocker/ It tells you how to make a 9v shocker out of a CRT monitor's flyback transformer. I really like the idea and I just have an extra monitor at my friend's house, so I thought about trying it. I saw some videos of people messing around with flyback transformers, and it really looks dangerous. If I follow the guide on the link, and get the shocker to work, will it be dangerous? I'm gonna use it for pranks and self defense(I'm a HUGE fan of knives and I know how to use them, but they're illegal to carry here and can cause serious injury), will it be ok? Thanks a lot, Mike.

Asked by netbus 7 years ago  |  last reply 7 years ago

9v VS 9vdc?

I'm working on an LED IR Illumination circuit (KipKay's nightvision with just the LED circuit). The thing works great but kills my 9v batteries pretty quick. I have a 9.6Vdc 300ma power adapter. Is is possible and SAFE to use this in the circuit instead of a 9v battery? Sources: KipKay's Project https://www.instructables.com/id/Super-Nightvision-Headset-Hack/ Power Adapter http://www.noiseguide.com/product_info/h_pro_96vdc300ma_adapter_ps200r120  

Asked by mrgrim333 7 years ago  |  last reply 7 years ago

Led powered by 9v

Hi all. I am new to this forum and need some help. I want to mount an led strip to the bottom of a roller skate. Everything I find already made up requires 12v. I need to keep the setup as small as possible for mounting reasons. How could I go about making a 12vdc led circuit work off a 9v battery or how could I wire up some led's on a flexible strip powered by a battery. I am thinking 9v because I can purchase a rechargeable set without draining the bank account each time. Any suggestions are welcomed. I have about 6" in length to mount the strip to. I would like multi color led but one solid color would also be fine. Thanks again for any suggestions.

Posted by rsfaze 11 years ago  |  last reply 11 years ago

9v battery simulation?

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

Asked by woodyd 1 year ago  |  last reply 1 year ago

a very hot 9V

Alrighty, sorry for the noob question, but i am very very new to this, i'm tryin hook 3 10mm LEDs to run off a 9v battery, i hooked it via the LEDcalc with correct resistors, it works just fine, but when i try to add a on/off switch into the mix the 9V gets very very hot. could it be ... the switch i am using... the 24 gauge wire to connect it all.... how i have connected the on/off switch into the mix , instead of connecting it straight to a battery i have added extra wires and put the switch in between the battery and the start/end of the LED chain... should i bump it down 6v instead with the correct resistors instead of the 9v also if you could explain why the 9v was heating up so much that would be great too....

Posted by pixelglasses 10 years ago  |  last reply 10 years ago

18v dropped to 12v?

I want to limit two 9V battieries, in serial to 12v. I want to run a cold cathode off em, if the strain is too much, I'll join two parralell sets of two 9v batteries in the circuit. Anyway, how do I do it? I can't find any 12V regulators at all, and I don't know what sort of resistor I'd need, is there one that would limit it to 12V, with the standard 9V battery ampage? How could I archive this? Thanks.

Posted by Josho 10 years ago  |  last reply 10 years ago

circuit to cut through plastic wrap

I can use a tungsten filament and only a 9v battery.i need the circuit to generate enough heat so as to cut through a plastic wrap.

Asked by snehap22 5 years ago  |  last reply 5 years ago

run a ps2 on a 9v battery?

The adapter says it runs on 8.5 v

Asked by 9 years ago  |  last reply 9 years ago

5v and -5v from 9v? Answered

How can I get +5v and -5v from a single 9v PP3? Not 4.5v, I could do that easily with a voltage divider. Preferably using only passives and discretes (Inc. voltage regulators)?

Asked by andy70707 7 years ago  |  last reply 7 years ago

Does anyone know how to convert 9vdc power to 12v dc power?

Does anyone know how to convert 9vdc power to 12v dc power? ive looked all over the internet and nobody seems to have any schematics for anything like it. It needs to be about one or two square inches. Its for a pellet rifle with a built in air compressor so i can travel through the woods and not have to worry about going back to the truck and airing it up. please email me at mongoose_08@yahoo.com thanks

Asked by mongoose_08 9 years ago

Solar 9V battery charger? Answered

I was wondering if you could make a solar 9V battery charger and if you can you show me how?

Asked by sf49ers 5 years ago  |  last reply 5 years ago

help with 9v to 5v to 3

I am trying to make someting liek this guy made here https://www.instructables.com/id/EZQ7ZDDF0JY1JSH/ where can i find a circuit that will give me outputs of 3v 5v and 9v

Posted by DELETED_kclv1988 11 years ago  |  last reply 11 years ago

9V adapter instead of 12V?

Hi,i have a led strip of 12V. but i dont have a adapter of 12V. so i am using a 9V adapter. does this damage the adapter or the led strip ?? thank you

Asked by pratheekprakash 3 years ago  |  last reply 3 years ago

Powering an Arduino with 9V batteries? Answered

I'm looking at powering my Arduino with 2 9V batteries wired in parallel (2 is optional, but if you think a single 9V battery can power an arduino + 16 LEDs simultaneously for >3 hours, let me know). I have a few different options for linear regulators. LM350 (3A), C33275 (300mA), LM7805 (1A, 5V) - I'm guessing I should use the LM7805 because it's fixed at 5 but I'm not sure. I'm not too electronics-savvy so as much help as you're patient enough to give would really be appreciated!

Asked by jonrb 5 years ago  |  last reply 5 years ago

Make a 9V powered zapper? Answered

My friend has this thing that looks like a pack of gum and when you grab and pull the piece sticking out it shocks you, it isn't really that powerful, but I want to make a better one.  I opened it up and it is a fairly simple device.  It has three button cell batteries with the negative side attached to a contact plate and the positive attached to the capacitor.  The capacitor has the neg attached to the same plate as the batteries negative.  The only problem is that the positive plate is attached to a third prong on the capacitor.  Why would a capacitor have three?  I have tried charging a 220 uf cap. with a 9v battery, but it doesn't deliver any shock even though it should be higher voltage and capacitance than the original device. 

Asked by jj.inc 6 years ago  |  last reply 5 years ago

9v to (5v-3v) for pic 16f628a

Problem: I have a 16f627/628 (runs between 3 and 5 volts) that needs to work in tandem with another device (call it D) running at 9, direct current, (active for 1 second in 30 or less frequent). Upon hooking up a number (of descending in size) resistors (without D connected) with the supply and 16f6xx the 6 LED's powered by the 16f6xx do not turn on unless resistance is extremely minimal, and voltage is well above that advised in the datasheet (not to mention making the pic reset itself every 10ms). Can anyone tell me how I might run the 16f6xx from a 9 volt battery, and explain what was going on? This may seem unforgivably dim to anyone who knows but unfortunately I'm more a software guy learning hardware as I go along. Any help would be much appreciated, Thanks Andy

Posted by andy 11 years ago  |  last reply 11 years ago

im new. questions about led and a 9v.

Circuit boardim trying to create a circuit board with leds on it that spells out my handle. i was thinking of using it as a throwie or like a calling card. im totally new to this so i didnt want to try and use a printed circuit board since i have never done anything like this before. i used a circuit board i bought at radio shack. im building it with standard super bright 5mm leds that are about 2.1 v and im not sure how many Ma. i assume 25 Ma. no matter how i plug these numbers into my formula (source volts - led volts / Ma) the leds always seem to run hot. i cant figure out what resistor to use. the power supply is a 9v battery. i also would like to know how to string about 30 of them together off one 9v. i know its alot but can anyone give me some advice or help me out?

Posted by mat_massacre 11 years ago  |  last reply 11 years ago

Can a ring illuminated 5A 250VAC pilot lamp (6v led lighted switch) control a mini pc fan using a 9v battery ?

The fan is for the combustion chamber of a spud gun and comes with an internal toggle switch but I would like to use the external lighted switch. Suggestions are appreciated, Thanks

Asked by JackH19 3 years ago  |  last reply 3 years ago

How long can a 9v battery power a few leds?

Hi I am trying to make a display of my polymer clay angry birds in our local fair and I wanted to add a few little leds on it, the problem is they need to stay on constantly for at least 5 days  I am trying to figure out how long a 9v battery would power about 6-8 leds. is there a better way to do it? ~Thanks  

Asked by AsherB4 2 years ago  |  last reply 2 years ago

Where can i find prints to a voltage multiplier for 9or 12 v?

I need to build a voltage multiplier for 9v to about 4kv

Asked by tulavatalo 9 years ago  |  last reply 9 years ago

Rocket Ignition Switch?

I have seen multiple high power rocket igniters, but none show you how to wire them.  I want to link three 9v batteries in a way that outputs 27v.  How do I do that.  Is the wiring (+|-|+|-|+|-) or (+|+|+|-|-|-)

Asked by jj.inc 8 years ago  |  last reply 8 years ago

is there a way to make a joule thief for a 9v battery?

Asked by Slicerr2 7 years ago  |  last reply 7 years ago

Multi- 9v or 12v outlet setup?

Does anyone know how to make or where to find a single wallwort (120v outlet) that has multiple 9v or 12 v out plugs? I've got alot of little electronics (mainly things that light up/ glow) and I hate all the blocks and power strips that I've got to use. (I'm in the US btw.) Thanks for any help! The Atomic Soul

Posted by TheAtomicSoul 10 years ago  |  last reply 10 years ago

Connect timer w Rechargeable 9v to Solar panel?

I am using a rechargeable 9v battery in my irrigation timers.  I would think it would be easy to hook up a small solar panel to charge the batteries during the day and then I don't have to worry about them failing and me not noticing until my garden goes brown.  Two wires join in a pastic coated cap that hooks to the 9volts.  Can't I just take the cap apart and connect the leads from the little solar panel?

Asked by solartimer 5 years ago  |  last reply 5 years ago

Trying to wire leds to a 9v battery. I am confused by different instructions.

Some say the resistor gets attached from the positive battery lead to the first led. Others say that the resistor is attached to the neg pole of last led and the ground wire of the battery. What the Hey?

Asked by ClandestineIntestine 6 years ago  |  last reply 6 years ago

how many ohm resistor do i need to get 5v from a 9v battery? Answered

Hello i am writing up an instructable on setting up a wireless receiver , however i requires both 5v and 9v output, and the whole point of it is that it is simple and cheap, so i need to know, how many ohm resistor do i need to step down 9v down to 5v? i do not wish to use a 5v regulator unless one can be bought for less than $2, or else the instructable will cost too much.

Asked by oldmanbeefjerky 7 years ago  |  last reply 7 years ago

Can anyone please calculate the color code for a 9v DC Resistor. Its the last thing I need to finish my whole project.?

I'm trying to light up the dash in my truck and everything is ready except im plugging it in to the 12v DC cigarette lighter and I know it will blow them all sky high but I already tested and 9v DC is what I need. Thanks in advance!!! 

Asked by TamaMan14 8 years ago  |  last reply 8 years ago

Wiring help!

I have an 8th grade science class (I'm the teacher) that I would like to have construct underwater vehicles.  The kids will be using 9v batteries, switches and assorted other materials.  Does anyone know of any good books/articles that explain the basics of wiring, electricity, motors, switches, etc.  that I can have the students read to get a good base of knowledge in the basics of electronics? Thanks!!!

Posted by mashmtz 7 years ago  |  last reply 7 years ago

How to charge a rechargeable 9v battery?

Hi guys, I am using a lot 9v volt batteries so I thought why don't I buy rechargeable but I found out that the charges where expensive. so does anyone know a circuit to make a charger?

Asked by bobbiy 4 years ago  |  last reply 2 years ago

How to wire 12v dc case fan to 1x9v and 2xAA batteries? Answered

Hi there! I'm planning a project using a 12vdc case fan to inflate a plastic bag for a school project. I have located a 9v battery clip and a 2xAA battery holder and was wondering how i'd go on with wiring them together. I was also wondering if it was possible to reverse the polarity, thus creating a vacuum effect. If so i'd like to have a 3 prong switch to control the case fan. I appreciate any help you could provide me. Thanks!

Asked by williamhaze 7 years ago  |  last reply 7 years ago


Hi, I'm building a mini BB-8 unit for a project and going to make many more for a club. My biggest problem I'm encountering now is the battery needed to power it. The entire circuit draws around 500mAh and runs  on 3-5V. I don't think a 9V battery is enough to power it or even a AA battery no matter how many i put on it. The online guides that I found uses 18650 batteries either salvaged or bought. However, from where I come its very expensive to buy this batteries and it the charger cost even more. So I was thinking of buying this cheap 2400mAh powerbank that is sold commonly here. It outputs 5 volts and can be charged by USB. This powerbank cost about the same price of a 9V battery but only have life span of about 2 months which is good enough in my opinion. My main question is are there any other alternatives to power this circuit at a cheap price and is it possible to use a powerbank to power this circuit? Tq for any help and suggestions.

Posted by KhayhenS 2 years ago

How can I make a spark gap powered by a 9 volt battery?

I had an idea for a project where I will (literally) Set Fire To The Rain. So I need a spark gap. Anyone know how to do this? I think it would be easy to charge, then discharge a flash capacitor. If that's a good plan, where can I find a schematic for a charging circuit?

Asked by 4lifenerdfighter 6 years ago  |  last reply 6 years ago

Make battery supply for 9V synthesizer

I have a Roland D2 Groovebox that I'd like to use portably. It uses a 9V 1000ma AC adapter that I've misplaced. I prefer battery powered stuff so figured I'd take this as an opportunity to try to make it so. I'm comfortable with some soldering and cable splicing, but definitely lack the electrical knowhow to even know what questions to ask. I'm interested in either buying a battery housing for disposable battery power (AA thru D cell) or making a wire that can plug this into a rechargeable power bank. I assume this may be an existing product but, again, I don't know how to search for it (and, again, would also be happy to whip one up).

Asked by ThomL9 5 months ago

What is the internal resistance of a 9V battery? Answered

Asked by Yashknowsbetter 9 years ago  |  last reply 9 years ago

converting a 9v dc adapter to 18.5?

I just recently got a free laptop from a friend who's dad didn't need anymore, and it dosn't have a power cord to charge the battery. I'm dieing to turn it on and see if it works so if anyone knows who to convert a 9v dc adapter to 18.5 if it's even possible.

Posted by CowGuy 11 years ago  |  last reply 11 years ago

zener diode (limit 9v to 5v)? Answered

Can i use zener diode  to limit voltage from 9v to 5v? ( i would use 5v zener diode ) can this work? what else do i need to use? and  is this way efficient? i was thinking to power my phone with this or to charge my light

Asked by tealk 5 years ago  |  last reply 5 years ago

Wiring two 9v devices to batteries...

I want to run a motor attached to a motion sensor in such a manner that the motion sensor triggers the motor. The motor is run by 6 1.5v D cell batteries, thus I imagine requires a 9v draw. The battery operated motion sensor also requires 9v. If I wire them in series, which I (hopefully correctly) understand would require 18v total and thus would require some number of batteries wired in series to achieve that total. Correct?

Asked by 9 years ago  |  last reply 7 years ago

hoow to make a 9v olar panel?

I need a way to make a solar panel put out 10 volts min

Asked by havejack 9 years ago  |  last reply 9 years ago

Solar charger in altoids tin for 9v??

Well, if you have seen the altoids solar battery charger, and the altoids 9v usb charger, then you must have thought, "why not put em together???". Now, Im not electronics buff, but I'd be willing to bet that since the 9v charger instructable is so small, that it could be incorperated with the solar panel kit. Now, my question is, would i have to do anything ridiculous to convert the solar charger (which is ment to charge 2 AA batterys) into a 9v usb charger w/solar panel while still being inside an altoids tin. PS: I still don't know why I have this wierd fascination with altoids tin DIYs, but I do...

Posted by altoidsrox 11 years ago

6v-9v trip wire for trail?

Layout of trip wires for 3 trail alarm with lights. About 250' range from panel no noise just lights on trip to panel.     Thanks Alan

Asked by picker2 9 years ago  |  last reply 9 years ago

9v controlling 2 servo motor?

Hi everyone! i am planning to use 2 servo motor and a LCD, all connected to my arduino. but of course, the 5v from the arduino aren't enough to power up everything. so my question is; can i use an external source (9v battery) to power up the motors? if yes,  how? appreciate the help. thanks. 

Asked by nurazureen 4 years ago  |  last reply 3 years ago

9v to 3v "easy button" hack. Answered

Hello! Im working on a Staples Button Hack! but..... Problem that I have is that I feel like it is a Waste to scrap the original "that was easy" message. And the problem that comes along with this would be that I have to use a 9v battery to power the new circuit and the original button circuit uses a 3v battery. I'm not great with Ohms law but I do relize that I need a resistor but... i do not know if that will put in too much current into the original circuit?Would anyone know how I can calculate this? And does the amount of current even matter? -Thanks! Noobiefied

Asked by noobiefied 7 years ago  |  last reply 7 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 11 years ago  |  last reply 11 years ago

DIY 9V DC to 110V AC inverter, and/or 9V DC to 19V DC transformer?

Hi, I want to build a 9V/110V DC/AC inverter, so I can power up things like my laptop with a car lighter socket. It would be always nice to be able to use electronics in the car when I'm traveling... What kind of components will I need and how would the schematic looks like? If DC/AC is a hard task, how would I go about building a 9V/19V DC/DC transformer so I can at least power up my laptop on the go?

Asked by ddolbi1 7 years ago  |  last reply 2 years ago

How many amps do i need to power two LED Cob 9v bars ? Answered

I was wondering how many amps would these two LED bars need in order to work if connected in series, and would a regular 9V battery be enough to power them ? http://www.dx.com/p/high-power-3w-7000k-200lm-white-led-puri-chip-emitter-metal-strip-12-14v-65783#.VgrNC9RXeK1 What kind of battery should i use if a 9v isnt enough ?

Asked by TarikS5 3 years ago  |  last reply 3 years ago

can a 9v be used to heat a piece of wire without the danger of blowing up? Answered

I am working on a costume that utilizes shape memory metal. I plan to use a 9v to briefly heat the metal to its transformation point of roughly 115F where it springs to shape but I would like to prevent any possibility of this momentary short circuit from blowing out the battery. I have yet to fully grasp the applications of diodes, transistors and resistors. is there any kind of simple setup someone may suggest? I've also considered the use of microcontrollers or relays but im trying to keep as simple as I can.

Asked by SideTracked350 4 years ago  |  last reply 4 years ago

What sort of resistor will i need for 8 IR LEDs wired in series and powered by a 9v battery?

I plan on wiring 8 IR LEDs in series with a 9v battery to power them. i pulled the LEDs out of some remote controlled helicopters so I'm not sure of the values. if there's a safe way to go, what resistor/s should i use?

Asked by tokymaru 8 years ago  |  last reply 8 years ago

my 9v batter is overheating on the LEDs (This was a DIY project I'm worried I messed up somewhere)?

Hello guys, I'm pretty new to LED work and this might seem like a really round about process to how I did this but I'm going to explain the whole thing and hopefully find a solution to my problem! First off I bought these Fairy Lights:  https://www.amazon.com/gp/product/B01MD1RQ6Q/ref=oh_aui_detailpage_o01_s01?ie=UTF8&psc;=1 I bought them to put into rave fluffies (that I hope to sell at some point) I've attached photos below of what they look like if people didn't know. I bought them because of the small battery pack so they could sit nicely along the legs and not bother anyone and, because they're rainbow and do a beautiful blinking pattern. The problem with them is that the battery packs completely sucked. Big time. They would work for about a minute and then start loosing higher voltage colors and then about at the 3 minute mark they would just be totally red. I figured they were crappy batter packs so I decided to mess with it. Rave Fluffies: http://ep.yimg.com/ay/yhst-11088499841243/striped-fluffies-monster-blue-pink-purple-white-24.jpg The fairy lights themselves were to short so, I decided to solder to strands together, then I trashed the battery pack that came with them and replaced it with a 9v batter pack adapter. I tested it out on some 9 volt batteries laying around the house and it looked magical. All of the colors stayed much longer and it was beautiful!  So, today I went out and bought some new batteries they're Energizer Max 9V. I put the fluffies on and put them in and I wanted to test how long they would last. By about 5 minutes I felt a burning against my leg where the battery was. I took the fluffies off fast and discounted the battery. It was extremely hot. Almost to hot to touch and it left two nice low key red burns on my legs. I don't understand what caused this when the other batteries were fine? I also used a 9V energizer battery before. But, the only difference is I'm not sure how much power was left in it while these were fully powered! I hoping to find a solution to this and hopefully it's an easy fix! Also, Bonus points to whoever can send me in the right direction to buy fairy lights like these. Rainbow, blinking, with a small battery pack that doesn't poop out on me fast. I would prefer not to do this much work or something I intend to sell but, if that's what has to happen it's not the end of the world. Thank you so much!! Much love,  Meisha 

Asked by MeganB126 1 year ago  |  last reply 1 year ago

How should I do it? Answered

I want to make a small inverter with 10kv output powered from a 9v battery. Can you help me with a schematic?

Asked by theVader75 7 years ago  |  last reply 7 years ago