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Search for 9V in Topics

9v to 3v

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

Topic by Flumesoft    |  last reply

9v shocker

Hey everybody. First, take a look at this question's best answer - 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.

Question by netbus    |  last reply

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 Power Adapter  

Question by mrgrim333    |  last reply

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.

Topic by rsfaze    |  last reply

9v battery simulation?

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

Question by woodyd    |  last reply

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....

Topic by pixelglasses    |  last reply

run a ps2 on a 9v battery?

The adapter says it runs on 8.5 v

Question    |  last reply

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)?

Question by andy70707    |  last reply

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?

Question by sf49ers    |  last reply

help with 9v to 5v to 3

I am trying to make someting liek this guy made here where can i find a circuit that will give me outputs of 3v 5v and 9v

Topic by DELETED_kclv1988    |  last reply

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

Question by pratheekprakash    |  last reply

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!

Question by jonrb    |  last reply

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. 

Question by    |  last reply

Is it safe to power a 9v=150mA (cordless phone) with a 9v 300mA adapter? Answered

I have a Philips CD250DUO cordless phone that has no user's guide , and a GE Atlinks cordless phone that is powered by 9v i50mA i wonder if i could use my 9v 300mA adapter on the Philips brand and can anybody tell me if there is free download of user's guide for this device

Question by jovenhatsjr    |  last reply

May I use a 9v 1A transformer instead of 9v 400ma one? Answered

I have bought a turntable which comes with a USA transformer 9v 400ma. I want to use it in Sweden so I have to buy  a European transformer. I found one that transform to 9v 1000ma. Is it going to cause any damage to the device if I use it? Thanks.

Question by terristel    |  last reply

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

Topic by TheAtomicSoul    |  last reply

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

Topic by andy    |  last reply

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?

Question by bobbiy    |  last reply

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).

Question by ThomL9  

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.

Topic by CowGuy    |  last reply

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

Question by tealk    |  last reply

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?

Question    |  last reply

hoow to make a 9v olar panel?

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

Question by havejack    |  last reply

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...

Topic by altoidsrox  

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

Question by picker2    |  last reply

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. 

Question by nurazureen    |  last reply

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

Question by noobiefied    |  last reply

Help with wiring a 9v screen to 12v

If you are interested in what i am doing with my wii check it out ( ?... ) 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.

Topic by Wiimote Master    |  last reply

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?

Question by ddolbi1    |  last reply

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.

Topic by Josho    |  last reply

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.

Question by snehap22    |  last reply

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 thanks

Question by mongoose_08  

can i convert 220v dc to 9v dc.....such that 9v is the power supply of 555 timer.....

No other  supply is given only 220v dc is given....current can 50mA

Question by aruntheaspire    |  last reply

Is it safe to power a 9V 4mA device (Boss DS-1 pedal) with a 9V 850mA adapter? Answered

I'm not sure how mA works. The recommended manufacturer's adapter outputs 500mA and a different one I found around the house has 850. The specs for the pedal ( say it only draws 4mA, so I think I'm safe but I'd like to confirm before I try.

Question    |  last reply

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?

Topic by mat_massacre    |  last reply

9v battery + arduino mini pro help?

Can anyone tell me what resistor to use with an arduino mini pro and a nine volt battery, i would work it out but my multimeter is broken and i cant find out the amps of the battery, i tried just connecting it to the raw pin and running a sketch but he chip gets hot very quickly. could i have permanently damaged my arduino? i am quite new to electronics and am using a tilt switch to open a parachute on a water rocket. thanks very much :)

Topic by sbateson  

Ruby amp 9v DIY guitar amp

The Ruby amp (by is quite simply the best 9v guitar amp on the planet. Ruby has many shades of sparkly clean all the way up to a great, natural overdrive. Because of its small size and low power consumption its perfect for building your own cigar box amp or mounting into a guitar pedal enclosure. If you have never done a diy electronics project then this is a great way to get started.  The kit comes all the parts you need  - pcb, resistors, caps, jacks, led, 9v battery snap and instruction sheet. Also I have added a couple of parts that you never seem to get included in commercial kits - a toggle switch and a dc jack (so you can run off a wallwart). Its fun, educational and at the end of the buid you have a real great sounding amp that can be used for busking, practicing in the park or for homerecording with a microphone. There are plenty of small output LM386 kits out there - only the Ruby is a real guitar amp as it has a jfet input buffer and a real gain control - oh and thers mods that can be done :) check it out at - heaps of videos and sound samples cheers

Topic by dogbox2012    |  last reply

how to convert 12v battery power to 9v? Answered

I need to convert 12v down to 9v(easy) but it must be a high amp output

Question by chippykiff    |  last reply

Will a camera that works with 12v still work with 9v?

Heres the cam(left side of robot);=Botwithcam003.jpgthanksthe yellow battery is the one i need now for the cam it weighs lots... so a 9v battery would save me unecessary weight, still that whole set only weighs 670 grams...

Question by amando96    |  last reply

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  

Question by AsherB4    |  last reply

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

Question by JackH19    |  last reply

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

Question by tulavatalo    |  last reply

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 (+|+|+|-|-|-)

Question by    |  last reply

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?

Question by solartimer    |  last reply

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?

Question by ClandestineIntestine    |  last reply

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.

Question by oldmanbeefjerky    |  last reply

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!!! 

Question by TamaMan14    |  last reply

12V from 9V battery or other easy alternative?

Hello, I need a 12V 0.2A(min) power supply for a project... I don't want to use any kind of strange or expensive battery because it's a gift for someone. I was planning on using a 9 volt battery, is there any easy way to build maybe a step-up transformer for it (needs to be very compact)? Or could I use AA batteries? I don't want to use 8 AAs though, I do know that's be 12 volts... Thanks, any help is appreciated. 

Question by j.hawkins    |  last reply