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 10 years ago

3 volt signal to trigger 7 volt? Answered

Ok,so I get a 3 volt signal from a detector and use this 3 volt to trigger an alarm which atleast need a decent 7 volts to function.The detector could take a max. of 5 volts input which I got from the 7 volts DC supply.This 5 volts fed,gets transformed into 3 volts after the detection.So let me make this clear,I have a 3 volt and a 7 volt supply.I need to use this 3 volt to trigger the 7 volt circuit.I know what you are thinking-a relay !right?but I couldn't get  a 3 volt relay anywhere(though I got a 5 volt relay).I can tackle this situation in two ways.1)Either by stepping this 3 volt to 5 volts and making the relay do the job.but how? 2)Or some circuit to use this 3 volt to trigger the 7 volts(like a relay but maybe by using ic's).This is the final part of my project and so please help me.

Asked by Adarsh_tronix 5 years ago

How many milliamp/hours is a duracell 6 volt lantern battery? Answered

How many milliamp/hours is a duracell 6 volt lantern battery?  I can't find this info anywhere on the web.  Thanks.

Asked by Noblenutria 7 years ago

How do you test a dc voltage regulator?

I have a dc volt regulator that reduces the voltage to around 12 volts. How can I tell if it is good or not?

Asked by DELETED_afw11 8 years ago

Illuminating Experience

Thanks to Andy-b and Joe for the 12 volt light ideas. I wanted to illuminate dug bottle shards embedded in home-made cigar box guitars. They have given me the means. Companies are selling similar lights for $29.95. Crazy!

Posted by trampart 10 years ago

Powering a 24 Volt sensor with an arduino? Answered

Hello!   Ok here is the issue. Right now I am designing a rain water collection system by having my down spout drain into a 55 gallon plastic drum. I want to cap the drum to avoid spillage. The problem is what happens when the drum is full and the rain is still coming in. I know there are plenty of mechanical ways to solve this problem but I wanna have fun with an Arduino I have laying around. What I am thinking is run a pipe out of the bottom that has an irrigation valve installed (for anyone who is reading that that isn't aware of what an irrigation valve is, it is and inexpensive solenoid valve that is used for unground sprinkler systems). I figure I will add a water level sensor to the inside of the barrel and then hook the sensor and valve together via my Arduino. From there type a little code and violaa I have an over fill protection device! Here is the problem: An irrigation valve is 24v and the Arduino is 6volts. I know I can get the 24 volts from a power supply down to 6volts via resister, but then how would power the valve? My goal is to NOT have to buy a 12volt 1" solenoid (i didn't want to spend a lot of money on this project). I am not sure if there is a solution to this problem, but being a very green/inexperienced electronics hobbyist figured could hurt to ask. Thanks

Asked by Mpc1055 3 years ago

can I activate a 24v relay using my house's power grid(220v)?

I am making an automatic  fish feeder and to activate it ? I'm thinking about using a 24v 1100ohm relay that I have laying around. My question is: can I do it? If not can I just put a resistor on it? It's supposed to be activeted a bout 15 minutes every day.

Asked by tgferreira184 5 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 9 years ago

3 volt voltage regulators?

Hi,I need a 3 volt voltage regulator,1 ampere(or lower).I tried looking for Lm 7803 but couldn't find it any local shops.Anyother alternatives?

Asked by Adarsh_tronix 5 years ago

multi voltage project for sons project

Hello I was wondering if someone can help us. We are building a school project that has 3 different lights on it. what we are trying to do is have everything work off one 12 volt plug in transformer. What we have is a 12 volt dc transformer for 2 led drivers and a 6 volt ac transformer for a turning table. We want it all to work off one plug-in style transformer. How can we do this and conceal the components in the base. Please help us. Thanks for any help.

Posted by chrisunderwood 3 years ago

voltmeter and ammeter

Hi guys, could someone help me with this thing,

Posted by mammotz 6 years ago

convert to watt?

I am thinking of buying a acid battery. Its specification says that it is a 12 volt one and it's AHC@20 is 200. Can anybody calculate the watt output. I am not sure but AHC stands for Ampere hour capacity. Thanks RajibAzam

Asked by RajibA 3 years ago

Connect engine to alternator, will it run?

I have a new diesel 3 H.P engine and an 80 amp car type alternator, 12 volt. A, will the engine run the alternator at full output to charge batteries? B, Can I fit a bigger pulley to the engine? Regards Brian.

Asked by trebby91 5 years ago

Solar page ad takeover.

The "Solar" projects page is pretty much a Chevy Volt advertisement.  A video about the Volt is set to auto-play for every "page" of instructables... of which there are only 5 shown.  I understand that websites need ad money to survive, but when those ads dominate the page and hinder the user from accessing site content it borders on ridiculous. When I click next page I'm greeted with the same giant, auto-play video ad and only 5 instructables.  I find this irritating. -Tom

Posted by tomzook 7 years ago

How to Limit Current on a 24V DC Battery Charger? Answered

Due to what I feel is a Bad design on the charger. I'm trying to limit current coming from a 120V AC to 24 Volt Dc Battery Charger.  The Charger Is what is supposed to be a  Plain 10 Amp Only 24 Volt Charger. However when hooked to a dead set of batteries the current skyrockets up to 30-35 Amps and it trips the internal 20 Amp Breaker.  Is there something I can do to regulate the current down to a better amperage ?  Thanks In Advance. 

Asked by BrandonF260 5 months ago

I want to run my 12 volt power tools ( ridgid ) using a 12 volt lead acid battery

I have been doing this for years and I finally found this line of tools that is small and compact and the battery fits in the handle and it has tons of power  the lithium ion 12 v ridgid drill and job max line. I tried to wire up the tools contacts to the small lead acid batteries I normally use and even a full size car battery but it failed to power tool because there is this small contact that the tool is requiring which the lithium battery has but obviously the lead acid does not.  I do this for heavy duty use such as continual sawing and sanding and things like that.  any suggestions I really need to make this work as I run a mobile business.  I am looking for a solution to over riding the need for that extra contact and I am fully aware that I will void the warranty as many of you may be thinking. Please help 

Asked by captainj954 5 years ago

Can this be done?

Can I wire these lights so i can plug them into a outlet in the house? 

Asked by rodsteryz 6 years ago

Resistors for a project, easy question!

Hi all, This is an easy question about resistors, its been years since I use any. So, I have a replay which is rate 12v DC and 2amp. The power supply is 12v DC and 6 amp. V = I X R R =  V / I so R = 12 / 2 = 6ohm So I need a 6ohm resistor? Is that correct? I can't believe I have forgotten this! thanks Gary

Posted by garynobles 4 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

Will a transformer that outputs 6000 volts work for a Jacob's Ladder? Answered

I've been looking on ebay to find a transformer to use for a Jacob's ladder, and there seem to be a lot that output 6000 volts, and they are at a price that I am willing to pay. So, will 6000 volts be enough to use in a Jacob's ladder? If anyone could answer this, that would be swell. Thanks.

Asked by mbudde 8 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

variable load DC volt meter?

I would like to build my own one of these with more settings and variable load and input voltages. Maybe someone has a more elegant solution? Something that would fit in a small box or maybe even a something to put in between the DC source and my multimeter Voltmeters

Posted by Menthol 8 years ago

How do I connect a PVD-150-31RS ( I can not find schematic anywhere?

I want to use this to regulate my variable volt ( 150+ volts DC) pedal power unit. This Martek power Inc. regulator is perfect and cheap. I don't want to do it by gut feelings, destroy it or even harm myself. I have build several 12 volt regulators but current supply ( 12+ Amps, expensive to build) is my mean concern.

Asked by bigplate121 8 years ago

Dewalt Radio running on batteries of different voltage, would you see a change in performance? Answered

I want to buy the Dewalt Radio (DC011) which can run on many different size Dewalt batteries. My question is will the radio be louder, run longer, or experience no change in performance if it runs on an 18-volt battery opposed to a 12-volt battery?

Asked by 9 years ago

run a ps2 on a 9v battery?

The adapter says it runs on 8.5 v

Asked by 8 years ago

24 volt motor run time

Hi all, We just finished a remote control lawn mower project that utilizes 2 24V wheel chair motors and two wheel chair batteries for drive power. The balde is powered by a gas engine. The unit weighs in at around 260 lbs and is used for some serious slope mowing. The issue I have run into is that I can only get about 1 hour run time before having to recharge. Does anyone have any suggestions as to how to increase the run time without decreasing power? Thanks

Posted by real57vetteguy 5 years ago

how to calculate battery current ?

i want to make a ps2 battery, but it is must be up to 5.65 A

Asked by Rendydevara 8 years ago

Any cheaper way to find out voltage Answered

Other than a voltmeter. They are like $200 and I don't want one that bad.

Asked by Chromatica 8 years ago

Do Resistors work the same on AC voltage??

This isn't for a project but I'm interested if resistors still work the same: Wattage, Resistance... Thanks :)

Asked by Yonatan24 2 years ago

question about thermal fuses

I have a blown thermal fuse in one of my fog machines,it is 10 amp 250 volt 133 degrees c.can i by pass it safely?(there is high temp limit switch on heating element)or can anyone tell me where i can get one or its equivalent?i found some online but they in thailand.hoping someone who knows more than me can tell me where to get this locally.the blown fuse has some numbers on it :se fuse sf129 e tf 133 degrees c please help

Posted by hvacmac 8 years ago

Fun withTransformers

Connect the output of 2 transformers in series...  12v  +  6 v. much as you would connect batteries in series. will it burn out?  will it produce 18 v as one would expect with batteries?......... 18 volts!!  yay!   hasnt burnt out( YET)... i wont leave this unattended. transmission of power is more efficient at high v.     sooooo... if i hook the output of a 10,000 v  neon transformer to 2 thin strands of wire( think magnet wire, or a single strand from stranded cable)   and input this  10,000 v into the secondary of a second identical neon transformer, will i get usable 120 v from the primary?  (attempt to run the second transformer in reverse as a stepdown) Nope... not YET.  Suggestions?

Posted by Toga_Dan 3 years ago

I just put this up on the Mythbuster's site......

I just posted the following over there, so hopefully a method can be devised to test this safely: (1999) A US Navy safety publication describes injuries incurred while doing don'ts. One page described the fate of a sailor playing with a multimeter in an unauthorized manner. He was curious about the resistance level of the human body. He had a Simpson 260 multimeter, a small unit powered by a 9-volt battery. That may not seem powerful enough to be dangerous… but it can be deadly in the wrong hands. The sailor took a probe in each hand to measure his bodily resistance from thumb to thumb. But the probes had sharp tips, and in his excitement he pressed his thumbs hard enough against the probes to break the skin. Once the salty conducting fluid known as blood was available, the current from the multimeter traveled right across the sailor's heart, disrupting the electrical regulation of his heartbeat. He died before he could record his Ohms.

Posted by Goodhart 10 years ago

how much backup can be obtained from 18650 (2600mah) battery and 5w led bulb as a load?

Hello; i have some basic questions and want to clear my mind. i want to create a portable power bank using 2*18650 (2600mah) rechargeable battery and 5w usb plugged led bulb (5v). So keeping in mind the above values how can i determine the maximum backup this setup can provide? i would highly appreciate if you provide some real life examples to calculate the above mentioned values.

Asked by askfriends 2 years ago

How power 5v security camera from car battery?

Hi, I'm wanting to buy a security camera that has a 5v DC input.  Here's the link: I'm wanting to mount it up at our gate (300ft from house).  Up there, I already have a solar panel that charges a standard car batter and it powers the gate.  I'm wanting to mount the camera up there and somehow power it from the existing battery. Is this easy?  Can I (a total novice) pull this off? Thanks for any help.

Posted by spodppl 4 years ago

How to measure verry smal current (amperes) with multi meter?

Hi I'm trying to measure how much current can be generated from tomatoes. Please have a look at and my question will make a lot more sence. What option should i use ( 200u, 2000u, 20m, 200m) if i use 20 on the voltage and i want to use the formula W=VxA ? It seems to me that the measuring in itselfs alters the numbers. The brightness of the LED changes. What is happening here ? How can i measure amperes ? On the picture: 1/ LED hooked up to a battery. Multimeter placed in series to measure the current. (the LED seems to light up but this is reflection) 2/ I turn the multimeter to 200m, the LED lights up very brightly. On the display: 03,8 3/ Multimeter is turned to 20m, the LED lights up. On the display: 3,29 4/ Multimeter is turned to 2000u, the LED lights up. On the display: 1197 5/ Multimeter is turned to 200u, the LED lights up but not verry strong. On the display 1  . Thanks to any one who can explain this to me in clear language. This are my first staps in elctricity-land. greetings, Maaike

Asked by dr zeezucht 6 years ago

How many LEDs can a 9 volt battery power in parallel?

Basically what the title says 

Asked by Zem 8 years ago

When a load is rated at 12 volts and hooked up to a 12 volt battery, does it consume all 12 volts?

This may seem like a very dumb question but I took electronics two years ago as a high schooler and cannot seem to remember much about it. So I have a circuit that has a bilge pump hooked up in series with a 12 volt battery. The bilge pump says 12 volts, I know that that means it must have a 12 volt supply, but if I hooked it up with a 12 volt battery, would there be any left over volts to say, power a small light? Here are links to the battery and bilge pump I purchased from Amazon: All responses are greatly appreciated!

Asked by cobrien2115 3 years ago

12volt battery to 5volt miniUSB

I'd like to be able to charge my MP3 player on my motorcycle, running off the power of the motorcycle. The motorcycle will put out 12.1 volts or so off, and around 14 volts running. What is required to bring that down to 5 volts? Will a simple voltage regulator be enough? The MP3 player will be controlling the amount of current going to it, so I don't need to worry about that, right? Thanks Jake

Posted by jaykup 10 years ago

Can a 7.2 volt battery with 3000 mah substitute for a 8.4 battery with 1100 mah ? Answered

Hi, I am Planning on going airsofting with my echo 1 m4 commando, but do not have enough batteries to make it. The batteries my gun came with were 8.4 1100 mah NIMH rechargable batteries but i have some 7.2 volt , 3000 mah NIMH batteries lying around that i use for my rc car. I would like to know whether using the 7.2 volt batteries will either harm the gun or the batteries.

Asked by Whitedude0728 9 years ago

I have a 6v solar panel. What resistor should I use to get it to 5v? Answered

I purchased a 6 volt output solar panel from radio shack and I need to get it to 5 volt. I have a large assorted pack of resistors but I am fairly new to what is what.

Asked by jeoncs 9 years ago

LED question

I just bought some LED's that i plan to run through a wire on a 9 volt with a push button on/off i plan to run 6 at a time. the green are 525nm 8000mcd and the blue (A SEPARATE SET) are 472nm 2500mcd

Posted by pbpenguin5 9 years ago

How to calculate resistance?

Ok, I need to figure out how to know what resistor to use. I know how to read a reistor, I just dont know how to use one. Say I hook an LED, a 9 volt battery, and a resistor in a circuit. I want to get the voltage down to 3 volts. How would I go about calculating a resistor reading? What ohm resistor would I use? How do I know?

Asked by Adum24 7 years ago

Possibility of an 80 amp 12 volt power supply?

I'm just wondering about the possibility of me building one of these? I basically want to power a car amp inside a house. If its possible, how much money would I be looking at? How hard would it be to find the parts? And would I be better off paying $500 for a good home receiver, vs $200 for a good car amp plus whatever the cost of the power supply would be?

Posted by cvxdes 10 years ago

how can i build a flourescent lamp that operates on 12 vdc?i want to build one like i saw on fishing lights .com

Anyone know how to go about getting the proper ballast to make it run on 12 volts dc?where i could get one?

Asked by hvacmac 8 years ago