10w led on motorcycle Answered

I have 3 10w led lights on my motorcycle, but they burning out in time. I guess its because 12v/11A sums up way beyond 10w? Is there some  easy solution, like resistors or diodes ?

Question by SamaelsL   |  last reply


10W audio amp?

Ok, so i want to get this one audio amp to work, but i can't seem to figure out how to wire it! the first picture is a schematic, and i have NO idea what the connections are, 1, 2, and 3 the second is a picture of the amplifier chip

Topic by Sandisk1duo   |  last reply


help wiring 12x 10w led chips

Hi I just bought 12 SMD white led. i want to make a distraction device for airsoft. I got the LEDs but now I need some newbie friendly help to connect these light and get a proper power supply for these. I don't know how much power will I be needing for them. Here are the details of the led lights from the ebay page SPECIATIONS Voltage: 9-12V / 900mA Chip: Genesis's LED 30Mil chip Luminous Flux: 900-1000LM Output Power: 10W Light Color: Warm White 3000k-3200k Cool White 6000-6500k Beam Angle: 120-140 i want to run them off a 11.1v lipo they are about 12v fully charged. its all got to be kept quite small too. i need to know what drivers i need etc. i also want it to be remote controlled. would this work as the driver? and ran the chips in 2S6P? http://www.banggood.com/8A-DC12-24V-LED-Strip-Light-Single-Color-Dimmer-Controller-With-Wireless-Remote-p-987970.html

Topic by Desolation91   |  last reply


How to connect 10W led + 12v Led Driver directly onto Arduino?

Hello there, can anyone give me an advice on connecting an 10W led + 12 volt drive to an Arduino Uno? it works but when i tried to connect to Uno it doesn't work anymore. Thankyou

Question by YuT6   |  last reply


Can I power a LED array with LiPo?

I want to power an led array of 10W LEDs connected in parallel with a LiPo. They are rated 12V and 1050A. So thought of connecting them to 5200mAh LiPo battery so that they all will get 12V and each will get less than 1050A. Can I do like this? Please suggest a cheap method to do this. Thanks Edit1: Thanks for all the answers. 1) The link for LED: http://www.ebay.in/itm/5-PCS-ACTUAL-10W-WHITE-LIGHT-LED-SMD-BEAD-CHIPS-BULB-LIGHT-LAMP-DC-9-12V-/281779856264?_trksid=p2054897.l4275 2)The battery is actually 11.2V not 12V, my bad. 3) I know I have to use individual drivers for all of them but I'm just trying out to find out a cheap alternative. 4) I want to make an array of 10 10W LEDs so thought maybe they will divide the current by themselves.

Question by AlekhK   |  last reply


How to drive a 10W RGB LED with 12v PWM? Answered

Hi all, I'd like to drive a 10W RGB LED, much like these ones found in the RGB LED floodlights. I want to strip all of the internal circuitry and control it with 12V PWM signals such as the ones that come from these controllers.  They all seem to provide around 4A/channel. My understanding is that each colour (Red, Green and Blue) needs around ~300ma, so I could use resistors, but as this is a fairly high power situation, there will be a large amount of power loss, and low efficiency. Is there another way ie with constant current drivers specifically for RGB chips that accept 12v RGB PWM input?  Thanks Joe 

Question by joearkay   |  last reply


How to connect 10x 10W Power LED?

I have 10x 10W LED, vf = 9V and fc=600mA. I planned to conect them 2 in a row and 5 rows in parallel. From this, i know that the overall row Vf = 18V and fc=600mA overall current drawn from the source = 3A (min) I plan to use 24V source to power this circuit, anyone can kindly advise me, 1. How I ensure the current into each row is constant at 600mA? 2. do I need voltage regulator or just a power resistor connect onto each row will do? anyone pls kindly advise.. Thanks a million PS: Happy new year to you all

Question by acidjc   |  last reply


Can I fit a 10W heatsink in a zippo? Answered

I want to put a cree XM-L LED in an old zippo, and I want to know if anyone knows how to fit a big heatsink in the top part of a zippo lighter, not in the base, and preferably able to buy everything from a hardware store, not ordered online.  Also, does anyone know how to anodize aluminum for added heat dissipation?

Question by jduffy54   |  last reply


Can I run 10w 12v leds directly form a switching power supply? Answered

Hi, I have a regulated switching power supply with 12vdc 400w output (similar item pictured below) and I need to power around 20 10W LEDs which are rated at 900mA. Can I wire these in parallel directly from my power supply since I know the voltage can't change meaning that the current (and heat) shouldn't really change? Thanks in advance.

Question by reducingmyconsumption   |  last reply


How to make a TDA2003 10W amplifier give less than it's rated output? Answered

I need to power a single 4w speaker, but can't get an amp for it, so I need to use the tda2003. Should I decrease the circuits voltage? Or is it not possible?

Question by DangerousTim   |  last reply


I want to make a joule thief to power a 10W LED (833ma @ 12v) from ~2 AA batteries, suggestions on toroid ? # of turns ?

My transistor inventory: Part #          Package TIP122       TO-220 TIP32          TO-220 2N2222      SMD 2N3904      TO-92 2N3906      TO-92 C1815        TO-92 BC546        TO-92

Question by yaly   |  last reply


can someone draw a thru hole board for RGB 10w LED with 12v input? Answered

12v input from car battery to power this LED   something swimilar to these 1 2 3 but cheap and simple cos i dont wanna use SMD some info   on LED and board

Question by turbiny   |  last reply


speaker problem?

Hai, umax speaker board is problem.i have  25w speaker and 10w speakers 2nos  any Idea to work on sony w700b led tv pls tell me the solution.or how to use 3.5mm jack on this speakers. 

Question by heartbeat1502   |  last reply


I have a white rectangle in my speaker box but don't know what it is. Please Help!! Answered

I need to get this replaced but i don't know what it is. It says 10W 8r2 j

Question by demonspawnedangel   |  last reply


common ground to 8 separate led driver (possible?)

Im about to wire my latest growlight , and it consists of 10pcs 10w chips, they will be driven by each of their own 10w  drivers, If i would wire as it normaly should be done , that would result in a lot of cable, and i have a long "stem" between the reflector and the foot where i am hiding the drivers! so then , i came up with the idea to wire all the led chips ground to a common wire , which i then split up in the foot  , to each of their own drivers. would this be possible , or would the drivers go nuts,    their different colors involved so driver will put out different voltages Had hoped to finish the project tomorow , so a yes or no is highly apreciated thanks

Topic by kristerh   |  last reply


Solar Panel for Water Feature Pump

I'm looking for some suggestions to run a 12v/3A bilge pump in my outdoor water feature using a solar panel.  (This particular bilge pump has a built-in float switch to shut off the pump should the water level drop too low).  Solar is my preference because it'll only run during the day. 1) What size solar panel would I need for this?   Most are described by voltage and watts of power (24V, 10W).  I currently have a 24V/10W panel I'd like to configure for this but it's specs only show it producing less than 1 amp. 2) Should I look for plans to build an DC/DC converter(?) to limit the voltage to 12v? 3) Is there a way for me to boost the amperage? Thanks for any help, links, or suggestions! Dave Nagy Florida

Topic by DaveNagy   |  last reply


Is my RGB LED broken, or am I just dumb? Answered

I have a 10W RGB LED like this one: http://dx.com/p/10w-1000lm-rgb-light-9-led-module-silver-white-9-11v-168507 It's rated to 9-11v, so I hooked it up to a 9v battery. The LED has 4 leads: 1) +9v 2) Red - 3) Green - 4) Blue - The green and the blue work as expected, and I can combine them to get cyan. The problem is with the red: 1) It won't combine with any other color.  If the red is switched on, the green and blue switch off. 2) It works on both polarities.... It turns on both with +9v and -9v. Am I doing something wrong?  Am I missing something?  Am I going crazy?  Am I just stupid!? Please help!

Question by Morgantao   |  last reply


Need help on led circuitry?

Hi everyone!  I have some 10W LED chip fowardcurrent 1050mA 9-12v I also have 12V 72W with 6.2A output driver. My question is what is the ideal amount of LED to fully utilize my power supply with optimum brightness? Pair up in Series or Parallel? Resistor needed? Sorry for my noobness. 

Question by uma111   |  last reply


How do you use a solar panel to light a 10w light bulb at night? And what kind of a solar panel would I need?

I want to make my own solar panel (a small one) for a school project, but I also want it to be useful for after the project as well. I need a small light to light something outside, but at night (because, obviously, I can see during the day). So apparently you need a battery to store the energy during the day, and a charge controller is really important. I've found a lot of useful sites and videos (and instructables) that show how to make solar panels, and a few that show how to connect the solar panel directly to a light bulb, but I can't seem to find anything that clearly explains the battery and charge controller part. Please note that I know nothing about the technology of solar panels, watts, volts, etc., and have never taken apart or made even a simple electronic device of any sort. The most experience I had with this stuff was when I made a small circuit with a light bulb, battery, and alligator clips sometime around the sixth grade, but I have no idea how all that works and all the numbers that you need to keep in mind (I did learn the basics a couple years back, but I've forgotten everything), so when I find brief explanations online that say you need a battery, charge controller, and you need to somehow calculate the correct capacity and voltage, I'm totally lost. Can someone please help me out and explain? Or at least provide a useful link or something? I've scoured the Internet, trust me. Unfortunately, I was unable to find anything clear or something in a "How-to" format. Also, I'm flexible on the 10w thing. A 10w light bulb was just the lowest I could find and I thought the lower the better. So what kind of a battery and solar panel (how many watts/volts, etc) would I need? Low cost is ideal.

Question by a Canadian   |  last reply


Broken bass amplifier

Hey, I have this 10w bass amplifier for home practice. Problem is that it gives no sound through the speaker, but it works fine through the headphone output. I have Checked the fuse, which was ok. I have also connected other speakers to the amplifier to see if it is the speaker itself that is broken, it seems like it is not. Seems like quite a curious problem, but can it be fixed? It sure would be nice to play without headphones again.

Topic by Henell   |  last reply


Solar light?

I want to build and install three lights about 10 watt each in my house garden. Powered by solar panel (80w),100ah dry battery. Instead of using energy saver bulbs , i want to use LEDs.one LED of 10w or more which give light equal to one LED. Can any gentleman help me to design this system with 8 hours battery backup. The lights should be turned at dawn.Thanks

Question by Sarfraz ahmad   |  last reply


how to build a portable speaker (for ipod) with a 10w speaker, 9v battery and a male adaptor, plz help!! :(?

I am attempting (but failing) to build y own portable speakers im trying to use a 4ohms / 10 watt speaker with a 9 volt battery and a male jack for my ipod i have assembled it all to the best of my knowledge but when i put the battery on the bare wires (testing if it works), ipod says music is playing but the speaker has other ideas.   this is my first build of my own and i can't get past this problem :'( any help would be much apreciated :)

Question by Reger3142   |  last reply


Is there a 5 Amp ~35v equivalent to the LM-317T Voltage Regulator? Need to build 100w LED driver

Right now I'm running a 10w LED with a simple LM-317T & 1.8 ohm resistor combo. I'm looking to get a 100w led and build a driver for it. Is there a voltage regulator I can buy with these specs, or does this cheap "hack" only go so far? LED Specs: 100w 28-32v VF 3200mA IF

Question by Fuzzy3D   |  last reply


How can I make an ammeter for ~5V DC up to 3A? I want to connect this ammeter to a microcontroller.

I want to connect this ammeter to a microcontroller ADC and display it on 7-segment displays. I guess a 10W resistor ~0.1ohms or something will be involved. I can obtain them easily. I want to make an inline USB ammeter. I am experienced with PICAXE microcontrollers and surface-mount.

Question by jdorne   |  last reply


Wireless charging of smartphones anywhere within a 30 foot radius, without-pad !

Just read there is a 10W transmitter IC that has been developed to power a receiver IC collecting 6W of that energy... Both are ASIC chips that can operate and power power mobile devices up to 30 feet apart. Even though the RF energy is deemed safe. I would plan on using a Faraday helmet and maybe lead under wear when next I visit a coffey house.

Topic by iceng   |  last reply


High power LED Ledengin 10W. How can I drive 4+1 of these from a laptop power supply?

Dear fellow hobbyists, I have four deep red, 10 watts Ledengin bulbs mounted on a MCPCB (as well as one cool white 10 watts bulb from the same company). I would like to bring them to life using a laptop power supply. I know that I do absolutely need a constant current to avoid getting SEDs or friods. Unfortunately my knowledge of circuits is very basic and several decades old. I have read and re-read several times the excellent instructubles tutorials and gathered more information from the web. I think I got it (well…sort of) and I have successful built a small array of inexpensive, low power (20 mA) LEDs, using a resistor as the current limiting device. However I am aware that this is a rather inefficient way to feed high power LEDs, particularly related to power dissipation (i.e. efficiency of the circuit). I would like to build a LED driver using either 1) the NFET + NPN circuit #2 from Dan (https://www.instructables.com/id/Circuits-for-using-High-Power-LED_s/) but I am not sure if the listed components are good enough to drive four/five 10W LEDs (mid power LEDs are used in the example), or 2) find a buck pack that does not cost a fortune and is guaranteed to work (National semiconductors seems to have a few at very low prices, such as …., but I am not sure they will do the job and how well) . Also, I would like to know if it is possible to drive the 4 red together with the 1 white LED from the same power supply, or if it is better to use two PS, each with its own driver? The two ledengin LEDs are LZ4-00R210 for the red and LZ4-00CW10 for the white bulb. I intend to drive them at 700 mA to maximize shelf life and the maximum Vf for this current are 13.76 V for the red (only one bin code) and 16.64 V for the white (for safety I was advised to use the highest Vf bin value from the datasheet as it is close to impossible to get the correct bin code specific for the bulb from the distributor). I am actually considering running the 4 red + 1 cool white LEDs all in parallel, with each individual LED having its own current limiting device (the inexpensive ones from Dan): a bit more involved but maybe the safest?Thank you in advance for all the help you can give me.Arcibaldo

Question by arcibaldo   |  last reply


Need a small amp for unpowered speakers (that are to be plugged into the TV).

I've got a TV with left and right audio out and unpowered speakers. I would like to plug into the audio outs but I need a very simple amp to power the speakers. Any ideas on where to get/build a cheap amp? Bonus points if it fits in an Altoid tin. I did find a 10W stereo amp kit over at the Electronic Goldmine for $24. I was hoping to possibly do it even cheaper. I don't want to end up with any remotes, etc for the amp. So simple is better.

Question by smasumur   |  last reply


Led light bulb uk

Hi , I wounded if any body would be able to help me out? I have been give a few led chip, all 10w 12v 900ma, have seen people make or replace lights in there house with 1-3w bulbs , but mostly there also in the us :(, and wounded if anyone could give me some light guided help   I live in the uk and would like to light my house on these if pos so if the first works ill have to make 9 more at least to change all my bulbs lol cheers and thanks :)

Topic by Xxxdvxxx   |  last reply


How can my soundbar be rated at 300W-peak/150W-RMS, amp IC only goes 78W, 5 drivers total 60W?!?

Pyle PSBV200BT. Audio amp IC is STA540. Speakers and marked ratings: Two tweeters @ 10W, 4 Ohm; two midrange @ 5W , 8 Ohm; and one sub-woofer @ 30W, 8 Ohms. PS is 18VAC@2.5A. Am I missing something. The numbers seem so wrong that I must be overlooking something significant, not just overseas marketing greed. The Pyle sounds ok, but my 17-year-old 100W Creative 5.1 PC speakers blow it away.

Question by MarioL111 


Broken PSU? Answered

 I recently seen an instructable on converting an old computer PSU into a lab power supply. I followed it correctly, connecting the orange wire to the brown, the green to black and a 10W Wirebound resistor across red and black. The PSU turns on and all of the voltage rails work (although some are out by +-.75V sometimes), but I can hear a faint screeching noise and the fan doesn't spin.  I though the screeching may be normal because all I normally hear is the fan, is this okay. The fan is rated at 12V 0.3A, but when I measured the voltage over it, it was only 3.4V, why is this and how do I fix it. Any help appreciated, Thanks. 

Question by R055_28   |  last reply


LED Driver Help!

So I have four 10 W LED's and I want to run them all together off of a led driver but I'm not sure what type of driver I need to get. My led's specs are. Color: cool white Luminous flux: 750LM Forward voltage: 9-12V DC Color temperature: 6000K-7000K Forward current: 1000mA Power: 10W Lighting angle: 160° So if someone could help me with wiring it would be greatly appreciated. I've worked with little throw away led's and risistors but I wanted to use some sort of led driver, or constant current device on what I'm doing, but I don't know how they work. I'm just trying to get something that will run all the led's and be cheap

Question by tylerrick14   |  last reply


Resistor values for common anode RGB LED? Answered

Hi,  I have 10w RGB common anode LEDs. Forward Voltage is R:6-8v, G:9-12v, B:9-11v. Forward current is 300ma.  I calculate resistor values as R:15ohms, G:1Ohm, B:3.9Ohms.  This is based on max Forward Voltage.  I was told I wouldn't need resistors but clearly that is not the case as in one of the LEDs the red has failed.  Is it as simple as putting the correct value resitor between each cathode and supply?  Also, if I were to increase the resisors to lower the voltage a little (i.e. R:7v=18Ohm,  G:11v=3.9Ohm B:10v=6.8Ohm) would that help keep the heat down? Many thanks,

Question by Summerly   |  last reply


Does and LED's current draw depend on its voltage drop?

I was under the impression that an LED will draw whatever current it can get it's hands on, as my 20w LED (rated for 13.5 - 15.0v and 1500mA) would draw 3A when running off a 15.2v 2A ac adapter. Now that I've killed the 15.2v adapter, I'm running it off of one of 2 12v AC adapters, either a 1A, or the 2A one, and the draw is always 750mA (under the max possible supply from adapter). But when running this same test with a 10w 12v LED, the draw is 1A and 2A (max current supplied by each adapter). Does that mean that an LED draws a current based off its Forward Voltage, or is there something else I'm missing?

Question by Fuzzy3D   |  last reply


How would one build an amplified (electronic) megaphone?

Sup guys. Im trying to start buildign an electronic megaphone, but i dont know where to ger started. I've looked online enough on building and amp, but  dont know if using a microphone requires a preamp on it. So far, i have a plastic cone for the physical part, and a 4 ohm 10W mid-tweet speaker to project the sound. All i need is to know if a pocket amp is sufficient to amp a passive mic loud enough over a crowd. I need need any superb audio quality, just something that you can actually hear what is being said. I would appreciate any plans and help. TY

Question by SteamOh   |  last reply


Can I run an LED at a high voltage? Answered

I want to create a discharge indicator for a capacitor bank. I planned to do this with a simple switch-resistor-LED setup. My LED has a forward voltage rating (as well as max reverse), and it has a max current rating. My capacitor bank is 330V, so once I calculated the resistance I needed for the 20mA I plan to use, I created a board of resistors that will give the required current and dissipate >10W.  My 20mA is 10mA less than my LED's max current rating. Its forward voltage is 2.8V. Even though I have proper current levels and power dissipation, will the 330V burn out the LED? I didn't think it would, but I wanted to look around and make sure. I couldn't find any definite answers. Thanks!

Question by TheMike25   |  last reply


LED to laser beam?

I have just started the optics section of my physics class and I was amazed to learn that one can use a simple magnifying glass to form a beam from an LED.  Could this be used with a high power LED such as a 100 watt one, and then a beam expander (backwards to compress it) to form a laser beam of sorts.  Obviously it wouldn't have a common frequency, but could one theoretically make a very high power, burning beam with this quite easily. I know from experience that holding your finger in front of a mere 10w led can get quite hot, so couldn't using a 100 watt led yield some awesome ant killing hotdog frying results?  If not, how many beam combiners would you need to make it work

Question by seedorfj   |  last reply


Help with powering chained LED strips?

It's been about 30 years since I had any formal training in wiring circuits, so excuse my ignorance.   I am trying to chain a couple of addressable LED strips.   The strips have the following requirements: Power consumption: 10W/M Length: 5m Voltage: DC5V So it's 50W for the length of one 5m strip.    I'm considering chaining two or more strips together.   The data chain can be as long as it needs to be, but the the manufacturer recommends powering strips every 5m.     Let's say I have a 5v 60A (300W) DC power supply.   Can I run multiple strips (I guess up to six 5m strips) with this wired in parallel, or do I need to worry about putting resistors in to keep it from overloading the strips?    Here's a quick sketch diagram

Question by reverendpete   |  last reply


What LED drive do I need to power a 8x10 Watt LED in serie?

Hi there, I am building a 8x10 Watt 12v LED strip for my father in law with eyesight issue (an "ambitious" project considering my poor knowledge of the subject ;) ). Attached an image of the project. I though it was simple but I am now totally confused about how I have to power it, the more I read the less I understand. 8*10 = 80 Watt = 80/12 = 6.6A So do I just need a 240AC to 12DC 7A driver or? But 7A seem pretty high for just 8 LED, somewhere I must be wrong, or not. My LED have the following spec. Model: 10W; Forward Voltage (VF): DC 9-12V; Forward current (IF): 1050MA; Thanks!

Question by GautierA   |  last reply


Question about opamp, resistor and capacitor? Answered

Hello i have some questions. 1.Im going to build a ROG Tonemender (http://www.runoffgroove.com/tonemender.html).What the 10M resistor do in this schematic ? and its ok if i use a smaller value like 2M or 4M7 ?? 2.If a opamp rated output 10W with 4 Ohms speaker, how many W i can get if i connect it with a 8 Ohms speaker ?? can i have the formula for this please. 3.My amp have output power is 100W , can i connect a 8 Ohms 26W speaker to the amp ? 4.I want to find an opamp like LM386 but use lower supply voltage (5v) can you give me some suggest please. 5.What type of capacitor in the picture bellow ? Thanks for advance. sorry for my bad English!

Question by login721   |  last reply


Solar LED 2835 strip with rechargeable battery, controller and night sensor?

 Needing help with a solar set up to recharge and power a small led strip with 2835 LEDs. I need a small strip of bright LEDs to light up a address block during the night and it is in a rock column.  I want the set up to be as visually minimal as possible.  My plan is to have a solar panel charging a battery during the day, have the sensor turn the light on at dusk and off at dawn.  I have a reel of 2835 LEDs and I want to cut a 1 Ft length of them and mount below the address block to illuminate it.  I already have all the mounting details set and how I plan on running the wires.  I will put the battery, controller and dimmer in a box on the back of the column and close it off and run the wires through the mortar to the LED strip which will be sitting on a rock shelf.  The solar panel will be mounted on the top of the column which is almost totally flat.  My questions and assistance needed is on the design of the solar components, battery, controller, wiring, design and if it I have it all correct and it will work.  I have done hours of research on the net and think I have an understanding of this, but would like one you electronic wizards to proof my concept and provide any input on things I might need to add, change or improvements to make it better or more cost effective.  I also searched previous forum questions and didn't see anything exactly like this. Pic is attached on my general layout, but here is what I have come up with so far: -12v 10w Solar panel, $20 -Charge Controller, $6 -20a Fuse, $0 -12v 5ah battery, $16 -LED dimming controller, $6 -12v Photocell, $3 -2835 LED 1 foot strip (cut from reel), $0 --I can provide links and further details to the components if needed, but they are all standard items that you can get on ebay or amazon Total cost not including box housing is approx. $51   (seems like there should already be something like this available much cheaper, but I have searched a lot and can't find anything.  I don't want one of those bulky solar LED lights and I want something that will stay on for at least 8 hours at night) I did the research and 1 ft of the 2835 leds uses about 4 watts.  Looking at all the formulas I found and the battery I intend to buy, 5ah, I calculated it would run the LEDs for 14 hours.   4/12 = .34   * 1000 = 340    Battery is 5000mah so  5000 / 340 = 14.7 hrs Does this sound correct? Next was determining the solar panel required. I came up with the 10w panel to have enough to charge the battery.   10w / 12v = .83    battery again is 5ah, so 5 / .83 = roughly 6 hours Is this correct also? The other items are components to complete the circuit, protect the battery and controller and have the ability to dim the lights if they are too bright. I'm hoping I researched enough and did correct calculations and didn't miss anything. But please provide input, thoughts and anything I might have missed.

Question by Ti6   |  last reply


Please help me with my LM317-T LED driver.

A while ago I bought a 10W 12V LED on line to see if I could build a small projector. Then somewhere, I hear you need to build a driver for it, otherwise you WILL blow the thing. So I start googling and tinkering and find a few basic formulas, P=IV, ==> P/V=I ==> 10w/12V=0.833A So I need to get a current of 833mA at 12v to run this light, next step. According to most sites, the cheapest way of doing this is with a simple LM317-T Regulator. The ADJ voltage on this is 1.25v, so, V=IR ==> V/I=R ==> 1.25v/0.833A= 1.5 Ohm. So I pick up a few regulators and a fist full of resistors at my local electronics shop, dust off an old soldering iron and thow it all together. Then I plugged it on to a 12v 1.0A Power Adapter. I'd heard the 317 had a Vdrop of about 3 volts, so I took some readings to make sure everything was ok. Got 620mA between the Power/LED, the LED/LM317, and LM317 to the Power, all is good. Voltage was 12.13v across the Power, 9.20v across the LED, and 2.91 across the LM317v (0.95 over the resistor). All the numbers looked fine. Here's where it got tricky. Knowing the LED was rated for 12v, and the drop over the LM317 was ~3v, I dug up a 15.2v 1.2A Power adapter, and plugged that in instead. When I took the readings however, my current was up to 810mA, but the voltage was still down at 9.56v. The Power adapter was at 15.20v, and the 317 was dropping 5.67v. This is the bit I don't understand. How can I get my volts back? I know the LM317-T regulates its current via the resistor, but I'd assumed the voltage was dependent on whatever you plugged in, minus a constant 3v drawn by the regulator. This assumption is obviously wrong. Is there a way I can get the voltage back?

Question by Fuzzy3D   |  last reply


Help Charging my Capacitor Bank Without Tripping The Breaker.

Hello. I need help with charging a capacitor bank I have. It consists of 10 capacitors: 4 4700uf capacitors and 6 6800uf capacitors. All are wired in parallel. I have been charging them with 110AC rectified to DC. The only problem is that whenever I flip the switch to start charging, it trips our shop's 20A breaker and you have to flip it back to start charging again. It trips our breaker every time and dims the lights making my dad angry. So I need some tips on what wattage resistor i need to use to keep from tripping the breaker. I experimented with a 10W resistor and that was way too much resistance. I am not allowed to experiment anymore until someone credible can tell me what to do. Thanks for your help.

Topic by tinstructable   |  last reply


Capacitor charging circuit using bd243c. Will it work?? Answered

I recently made a schematic to charge a capacitor bank for my coilgun.D1-D4 are all 1n0007 t1 is a centre tapped transformer which will step up 12v to 330V. WIll it work. r1 and r2 are 10w resistors. Q1 and Q2 are BD243C with a rating of 65 watts.  i found my transformer from a very old cassette player. huge and heavy able to pump about 100W. i don't bother about charging time. I just want to know if it would be good. don't worry about the voltage monitoring i have a small voltmeter(like a watch. chinese product.) i am just want to know if it will work or not UPDATE: I have tried the shematic. It works flawlessly.  

Question by ARJOON   |  last reply


need help with high power LED light array drivers? 20x10watt running on 12vdc in car

I want to build a led light array for my 4x4 im thinking somewhere around the 10w mark not sure weather i should get the 12v ones or the 4v. fabrication and cooling i can manage my question is about the drivers.. can i use a buck-boost dc-dc converter as the driver? i understand they will even out the voltage thats caused by engine cranks and charging.. roughly 10-15v change. i plan yo use about 20 leds, yes i want it to be super bright and i realise that it will get hot. but i dont want to be spending to much per led on drivers, factoring in that i need lens's for each aswell. so i was hoping to run a few leds on one driver/buck the save some coin. a company called xmitter make something similar but they charge something stupid for them cheers. 

Question by grimgroper   |  last reply


Is this solar setup flawed? Answered

I have a 12V 10W solar panel that I'd like to use to charge a smartphone and/or a battery pack (5000mAh-15000mAh). I realise it's not a large panel but smartphones aren't that greedy and my use would be moderate. I was hoping that I could just attach the panel I have to a car lighter receptacle and use a double USB plug that I already have. Is this a sensible arrangement? The advantages, to me, are that all I'd need is a $5-$10 receptacle and I'd have a very simple setup (no inverter or charge controller, well, I suppose the USB plug would be a controller, perhaps). Would this system work? Even if it did work would it be an efficient set-up? Would there be any danger of damage to smartphone or panel? Also: will I need to earth anything or are the devices I charge capable of earthing? Would I need a diode to stop charge flowing back to the panel when there was no sun? Thanks for reading, I'd really appreciate any input on these questions.

Question by faintingcabbage   |  last reply


LED Turn indicator for Motorbike

Hi Everyone, I'm new to this forum and joined to get some help from all the geniuses here. I'm making  LED turn indicator for my 100cc bike. My present Factory installed flasher rating is 12v 10W X 2bulb. I want to add total of 48 ORANGE LED, 24 in front indcator and 24 in rear indicator. The current drawn would be much less for the flasher to work as the LED would not flash. I want to make 4 parallel set of 6 LED in series. as the total volt would be 2.2v*6 led =13.2. I've achieved the above so far but how to make them blink? Flash would be better then blink !! So can anyone suggest me a simple circuit which I can put in place of factory installed flasher and work the same way. I've 12v 7.2Ah Battery on board. and one thing more If I hook up a 55w/55w headlamp directly to the above battery how long will it last. I'll be grateful for the pain you take for me... Thank You Gurdeep

Topic by gurdeepsyan 


I do dvd presentations in rural Kenya, and most venues are off-road. What battery do I need to power my set-up? Answered

Since most of my venues are off the road, I need a battery that is not too heavy so I can cart it on foot. My presentations are usually only one hour long. My equipment is as follows: A Sony 2000 lumen lcd projector. On the back plate it says:100 - 240 volts/ 2.4 - 1.0 amps, 50/60Hz. An Armco DVD-DX600 dvd player. On the back it says: AC 240 volts -50Hz -25W An AMPEX AX575MS amplifier. On the back it says: 18W+10W*2(RMS) P.M.P.0.1000w, Impedence 4(OHM) Frequency response: subwoofer amplifier: 20hz-20hz; satellite amplifier 100hz-20Khz; subwoofer speaker:20hz-300hz; satellite speaker 100hz-20khz; separation: >45dB; S/n ratio >75dB My presentations are usually only one hour long. What’s the total current load of my system? What size battery do I need to run this rig for one hour?  Do I need a marine battery?  A deep cycle battery? Any specific battery you would recommend? Thanks, MamaJoy

Question by Mama Joy   |  last reply


Direction/turn signal indicators making them brighter with led bulb I need help pls

Hi. I somtimes ride a 1985 yamaha ms50 pogal 50cc moped. It has an 6v electrial system where as modern day scooters are 12v. I bought a knew indicater relay for it and checked all the bulbs as the turn signal indicators are not so easy to see flashing. I mean, on average sunny day other road users would need to look hard to see them flashing. the bulbs are 6v 15w and both old and knew flasher relays gives output of 6v 40w. I would feel much safer when turning if I had a bulb that gives a brighter flash to give other road users a better idea when im turning. I can see on the web there is a 6v 5w and 10w bulb I can try or even 6v leds but I dont know much about leds. the stanadard factory fitted indicater buld 6v 15w gives an ok flash at night, but in sunny daylight I would need to be close up to see it flash which is no good! I don't want to change the originality of this little ped since it has been carefully taken care of over the years and has made it in intact into current times as is. I need to come up with somthing that will work and if I replace a buld with a 5w or 10w when it should be 15w I may get a brigher flash or just blow the bulb. I wonder was there a problem or just bad design with the indicator lights on the yamaha ms50 pogal when they first came out in the 1980's as I have seen a couple of them fitted with suzuki fz50 indicators and other makes of bike turn signal indicaters on them. I don't think the flashers are faulty I feel they where just made that way. I could be wrong. I suppose there could be a bad earth on the flashers. Sorry to go on so much about this. Im looking for your suggestions for a brighter indicator flashers which is purely for safety reasons. If car drivers can see where im turning, im less at risk of being nocked off by them. Im thinking a higher or lower wattage incandescent 6v buld or even a replacment 6v led buld ive seen on ebay but as I said. I know nothing about led bulbs or even if they will work on my moped. Would a equivalent 6v 15w led give a brigher flash than a 6v 15w tradisional incandesant bulb? can someone help me here pls Here's the led ive seen on ebay http://www.ebay.co.uk/itm/2pcs-E10-6V-9V-12V-24V-INDICATOR-LIGHT-BULB-LED-WL-ay-/330859527741?pt=LH_DefaultDomain_3&hash;=item4d08c3be3d these are the standard 6v 15w bulbs i want to replace with brighter led bulbs http://directshopping4u.com/6voltvehiclelighting/P244A10  

Topic by selectauto 


Help with a school project on solar power

Hi. I have a science fair coming up in May and I want to do my project on solar power but I really don't know too much about electricity. This is my plan, please correct me where I'm wrong and tell me if there's a better way to do certain things: I am going to buy a 10w 12v solar panel (I might be able to get a 40w for a bargain) which will charge a battery. Would it be better to get a 12v lead acid battery or a 12v lithium battery? Lithium batteries have DC jacks instead of normal terminals on lead acid batteries so how would I connect the battery in parallel to the 2 devices I want to power? A splitter like this would work but it connects it in series? Although I suppose it doesn't matter because I just need to show that it works at the expo but I'd like to use it now and then. The battery will connect to a 12v LED light and a 12v to 5v USB charger. What about diodes? Do I need them? How will I make sure that the device charging doesn't get fried? Thanks a lot, I appreciate it. EDIT: A charge controller isn't necessary, is it? I'd also like to add in a switch to cut off power to the USB ports, power to the light and power to the battery from the solar panel. This would cause a problem if everything was connected in series.

Topic by Charly_ZA   |  last reply


Convert A/C to Battery Pack?

Ok here is what i wanna do, and your all gonna think I am crazy, but this is mostly for my little girl.  I want to take a very cheap dvd player and another cheap video screen, (the kind you find for the back of auto head rests) and glue them together, make a battery pack, and wire the two together to the pack and, the point is I have the devices and they both are rather low energy draw devices, so i just need to know if I can make a battery pack or perhapse a radioshack project battery holder and how many batts I would need etc.. I will admit the math is a bit confusing for me. but here it is, the dvd player is rated as AC 120 v, and it says it has a draw of 10w, which if I am not mistaken is very low drain and awesome for an ac device.  the monitor is DC with an adapter but can also have an optional car adapter (which I don't have, but I would just use the transformer's cord/jack to wire it in.)  The back of the monitor says it's DC output is 1.2A and again 12v and the transformer itself says it's input is 24w.  So if my math is right, I am looking to make a battery supply to support a total of 34 watts and then I will use both cords to wire them parallel to a battery pack that I need to make, so where I need the help is what kind of a batt pack do I need to make or is it even possible? 

Question by blackmagickfox   |  last reply