Opto Isolator? Answered

From everything i have read it looks to me like you can use an opto isolator with different output voltage as compared to the input voltage. 5 Vdc input side and 12 Vdc output side. Is this correct or have i got this all wrong? 

Question by WWC   |  last reply


What is the difference between a relay and opto-isolator? Answered

Hi all, I've looked around a bit and I don't really understand how opto-isolators and relays differ in terms of application (I understand that one uses magnets and one uses light). Can somebody shed some light on the differences, if any? (P.S Bonus imaginary internet points for creative analogies) 

Question by jonrb   |  last reply


reducing noise from chain driven garage door opener to apartment above. GDO is mounted to cement ceiling..need isolators

, when GDO is opened, the initial start causes a big bang , which abruptly  awakens  the people in the apartment  above. i  am not the garage user or apartment  resident. however it seems there is a relatively easy solution to isolate the noise.  When i had my GDO installed , i knew of these problems and opted for a belt driven since it is quieter, but for all i know the , a new resident could move in and i could be an annoyance. She had the installers return but , they just know how to follow the instructions. i looked into this a couple years ago,  i saw  in some GDO homeowner  handyman site the same problem and i read  that there was an isolation piece of hard rubber that would go between the cement ceiling and the GDO  hardware that attached to the ceiling which would reduce the noise transmitted to the apartment above. i looked a couple years back and  couldn't find  the supplier of this  rubber noise dampener/ isolator. Anyone have any ideas on how to quiet the problem, or is the chain too long and that is adding to the BANG when the GDO starts

Question by escapefromyonkers   |  last reply


Police searching a computer put a 'black box' between the computer & drive, to read, but not write, alter or erase data.

How do you build such a device? I wish to add a second hard drive to my ThinkPad A22m laptop, for a protected archive of books, websites, programs, and pictures. I want to have a switch so that at intrevals I can add files, but if a virus got loose in the computer it could not get into the archives.

Question by Johenix   |  last reply


ISOLATION TRANSFORMER 120 to 120v

Often a GFCI is too sensitive outdoors. But I've heard that an isolation transformer might save you from electrocution. How safe would an isolation transformer be for running a fan, angle grinder, blower, space heater, etc outdoors? Where can I get one that will handle the amps I need?

Question by Toga_Dan 


Isolation transformer current limit

I want to make small isolation transformer mainly for working with LED lighting. Can i put 1.36μF capacitor in series with transformer (primary or secondary?) to limit current to 100mA? (24W Max) could this somehow deform waveform preventing capacitive droppers or other common LED drivers to work properly? Inductor used for same purpose would need to be horribly big and resistor would be cooking.

Question by AnotherD1   |  last reply


Shure Noise Isolation Phones

I have Shure e2Cs. But i've always wondered what the difference was between the g (gaming) series, and the c series. EG. The difference between the e2C and the e2G. I though someone here could tell me. -Regards

Topic by evy-wevy   |  last reply


isolated buck converter idea Answered

I was wonder as a proof of concept, will this work? this schematic below works by charging a high current capacitor which has a small amount of series inductance to temporarily limit the current, and after charging, the switch (similar to the H bridge configuration) dumps the charge into a storage/smoothing capacitor. By using this method, one can eliminate the cost of transformers in isolated buck converters. A control circuit will control the pulse width into the smoothing capacitor through a negative feedback loop (AKA, as the voltage on the storage cap rises to a target value, the PWM will decrease until the high current capacitor is permanently connected to the DC supply. as the voltage drops, the duty cycle will increase to a 50% maximum.) I am just curious why this might not work, and if it does, does such a system already exist?

Question by -max-   |  last reply


battery isolation for portable power. Answered

Iv been trying to wrap my head around what im trying to do and cant quite figure it out. Pretty much i have salvaged 8 18650 size cells that i would like to run in parallel to make a portable battery. In order to boost capacity, i would like to buy new cells and make another pack that is parallel also. I want them parallel so its a nominal 3.7v system that i can boost to 5v for USB devices I know its bad to run old and new batteries in parallel do to various reasons such as self discharge. My idea is have 2 usb ports for one pack and 2 ports for the other pack and have an input/output protection PCB per pack. Now to keep this more portable i only want to use 1 charger and this is what confuses me. I can charge each pack separately, but that would require me to swap packs on the charger, and i would rather not have to worry about doing that. Long story short, how can i charge 2 battery packs at the same time but keep them isolated from each other? Diodes maybe? Also with how the protection circuits work having the charge leads connected to the output leads and the batteries on there own leads, when the charger is outputting over one amps, will it hurt any device plugged into it or will it regulate the current down to one amp with no harm done? Link to usb charger and protection circuit. http://www.ebay.com/itm/221424010115?_trksid=p2060353.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT http://www.ebay.com/itm/400679842464?_trksid=p2060353.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT

Question by Ksp3cialK   |  last reply


can anyone help me with Opto-isolator and Arduino problems

Basically i have tried to connect a Remote control to an opto-isolator via positive and negative wires running from the sides of a button, and then connected the opto - isolator to the arduino via ground and digital pin. I am a programmer and have written a home automation program to control this digital pin on the arduino, and when the pin is set to high the button is pressed on the remote control. Now here is the tricky part. I know that the pos/neg wires are correctly soldered on because you touch them and they make the connection and turn the Remote controlled socket( which is controlled by the remote control) on and everything is lovely. But when the opto-isolator is involved you get the nice blinking LED on the remote control to signal it is sending, but the socket does nothing. Again i have tried the output circuit on the end of the opto-isolator with a 9v batteries and an LED and they are fine.  Working nicely. Another thing to note is that te multimeter showsthat when using the opto-isolator and the remote control the power is the same as if you pressed the button.   I seem to be tearing my hair out here, so anyone who can give me an answer would be on my lifesavers list for life! Before anyone suggests using anything else like a transistor,Relay etc, it must be an opto-isolator as this is a project i want to do centering around opto-isolators. Cheers Mark 

Question by MarkFW   |  last reply


GREAT ELECTRONIC AUDIO ITEM JUST CAME AVAILABLE

The Electronic Goldmine  has a rare to find component. "Tiny audio optocoupler is about the size of a pencil eraser and has 4 leads. These are used extensively in audio compressors, audio level controls, audio limiters, expanders/noise gates, guitar tremolo effects, guitar amplifiers and music effect boxes. Inside the black epoxy case is a 2 lead photocell (not a photodiode or photo-transistor) and a 2 lead LED. This is why the device finds extensive use in audio applications (photocell instead of photodiode). The LED requires about 10-16mA current and the resistance of the photocell varies from 150K up to megohms when the LED is off to under 400ohms when the LED is on." A

Topic by iceng   |  last reply


Make your own opto-isolator? Answered

I am wondering if it is possible to make your own opto-isolator from an led taped to a photo-resistor with electrical tape. Is this possible?

Question by josh1324   |  last reply


How do you build an isolation tank?

Im interested in building an isolation/floatation tank.  Could anyone please help? Thanks.

Question by bradwell   |  last reply


Isolate Boron?? Boron Carbide T-Shirt?

How would I isolate elemental boron??  Can I remove it from borax?  Also can anyone tell me the ratio of boron to water to make a boron carbide tshirt.

Topic by Moonman0922   |  last reply


(newsletter) Cobweb Shooter, Lightsabers, Isolating Splenda...

Oct 16, 2008 Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; } window.open("/newsletter/newslettersignup?email=" + src.value,"newslettersignup1","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); } Welcome back! The Party Like It's 1929! Contest has begun! With the economy in the toilet we need to find clever ways to save money, live with less, and reuse what we've got. Remember the Great Depression? We can definitely do better this time around. Share your cash-stretching tips and tricks, and win something useful! The DIY Halloween Contest is underway! We've partnered with some of your favorite websites to bring you the biggest and best Halloween contest ever -- and we've got tons of great prizes to give away. Show us your best costumes, treats, gadgets, jack-o-lanterns, and more! Check out the entries and get inspired for the best Maker holiday ever. Enter your food or kitchen-gadget hack into the Hungry Scientist Contest and win your choice of a Kitchen Aid mixer, a super nice knife set, or a Le Creuset Enamel Cast Iron Cook Set. Help us with your answers for our Burning Questions and win a cool prize pack! The winners for the Craft Skills Contest have been announced. See who won!Live near San Francisco or planning a trip? Stop by for one of our build nights and make something awesome in our office! October 23: Halloween open build night. Mirrored Disco Ball Halloween Costume by atozfriendly DIY R-STRAP for DSLRs by amyles World Egg by pixelinabitmap Papermate Boom for Bluetooth Headset by CobyHoff Tons and tons of spooky and amazing prizes!Win some sweet tools for your kitchen with a food hack! Creepy Cobweb Shooter! by Kipkay Camera mount for a motorcycle by kaptaink_cg Low Cost Jacob's Ladder by bloomautomatic The $1 Waterbrush / Ink Brushpen by El Rey Make your own lightsaber! by nagle Make a House Goblin Peeker by cudubh Canning Tomatoes: Roasted Salsa by Forkable Hellboy Good Samaritan replica by peter.p.scherr 10 Instructables for aradical new look Share your best money-saving tips! Halloween Bloodbath Fountain by DIYDragon Add rapid-fire to a mouse with a 555 by mothflavour2 Carve patterns on an emu egg by bbstudio How To Isolate Splenda by Mongpoovian Now go make something awesome, and I'll see you next week! - Eric Sign-up for this newsletter: function openSubscribePopUp(src){ var emailValidate = /\w{1,}[@][\w\-]{1,}([.]([\w\-]{1,})){1,3}$/ if(emailValidate.test(src.value) == false){ alert("Please enter correct email"); return; } window.open("/newsletter/newslettersignup?email=" + src.value,"newslettersignup2","status=yes,scrollbars=yes,resizable=yes,width=420,height=250"); }

Topic by fungus amungus 


do I need to isolate a negative ion generator?

I am looking to build a negative ion generator based spark gap... I need to limit dielectric loss, and need to use 8" of small gauge wire to and from the switch to turn it on. do I need to isolate the switch electronically from the rest of the circuit? if so, would a reed relay do the trick? if I use a reed relay, could I run it from the same power source, in parallel, or do I need to isolate power sources as well? my setup will be slightly similar to the Electrifried shoe diagram below. (no, that's not the project)

Topic by gschoppe   |  last reply


How to isolate a battery pack from a controlled short?

so i am trying to make a portable electric stove and am trying to isolate the heat coil from the battery pack itself i know there is a way of doing this however for the life of me i cant remember how it works or what it is called. any help would be greatly appreciated! [edit] so there was some confusion on what i am trying to accomplish. i keep burning up batteries (when i say burning up i pretty much mean just that.) they don't like being connected to circuit that's sole purpose is to short out (albeit in a controlled way.) i wanted to isolate the batteries from the part of the circuit that is shorting to create the heat. if that still doesn't make sense or you think my problem might be something else entirely, please let me know. also so you know what my circuit looks like. it is a battery box power supply soldered to my heat element as well as a variable resistor to allow me to change heat output. hopefully that helps clarify.

Question by siege10   |  last reply


Isolating the lens assembly and LCD from a digital camera

Hello, Instructablers, I hope you can help. I'm trying to make a functional pair of night vision goggles based on the premise that digital camera photosensors detect IR range light while the human eye cannot. I have an old, functional Sony cybershot that I'm willing to scrap for the job, but the innards are far more complicated than I was expecting. As I am trying for a wearable, head mounted unit, I would like to shave off as much bulk from the camera unit as possible -- I do not, after all, still need picture taking capability anymore, merely a digital display. Any suggestions on where to begin? EDIT: Correct me if I'm wrong, but the more I think about this the more it seems like it would be more practical to buy a standalone microcamera and mini LCD. However, what method of output and input would these typically use? Would a simple microcontroller like Arduino suffice to perform all the necessary processing to feed video from the camera to the display? Does any of this even sound reasonable? Thanks in advance and sorry if photography isn't the right section for this, Ninepound

Topic by ninepound   |  last reply


heat isolation, how to keep heat away from electrical cords? Answered

 hi, we're building our own heating system. we're using ventilation tubes(often used on dryers) to distribute hot air through the shed, but it needs to get pretty close to an electrical cord(+/-1 inch) and the tube gets pretty hot(at least 200 degrees Fahrenheit). which is a bit of a problem, the electrical cor is the type you'd burry in the ground, and it looks like it shouldn't melt too fast, but we still ant to isolate it, any hints/tips on what kind of material to use would be appreciated... 

Question by lieuwe   |  last reply


Wiring diagram of B0505S-1W 5V to 5V converter DC DC power module Isolation

B0505S-1W 5V to 5V converter DC DC power module converter 1000VDC Isolation. Need the wiring diagram of this component.

Question by Sayan_trex   |  last reply


Can I Use Opto isolator to protect my arduino and other components connected to its 5V pin

So I am using two power sources. 5V from arduino and 12v 2A transformer for my stepper motor. 5V and 12V share common ground. My problem is that other components(LCD display, Water level Indicator) connected to 5V source from arduino won't function correctly when 12V is on. I think because my 5v isn't isolated and excess voltage from 12V goes through it.  I use 12V to power up my stepper motor and relays. Can optoisolator do the job in isolating these two voltages voltages?

Question by AlyzhaO   |  last reply


How to create objects using the molecular structure as the blueprint?

I am curious if it is possible to isolate then combine specific molecules into a desired object. Something easy to explain with is the molecular structure of Iron. We know what the structure is and what it is that comprises it. Would it be possible to isolate the different parts, deconstructing, the molecule and then rebuilding the molecule, re materializing, an iron molecule.

Question by ODIS2100   |  last reply


great site with iPod Noise Isolation Earbuds for only $2.00 shipped and other electronics!

I found this site that has cheap electronics. So I thought I would share it with you. dealextreme I only mentioned the earbuds because they were the main reason I visited the website. Hope you search the website and find things you are interested in purchasing.HAVE FUN!!!!!

Topic by kimmud24 


Can I run 1500 Watts Electric heater with a BT136 TRIAC?

I wish to make a preset timer switch that can carry loads > 1000 watts. I plan on using a 555 timer preset to a certain value then connecting it to a BT136 TRIAC through an opto-isolator. Is it feasible? If not what are the other options I have? Thanks in advance!

Question by raftor   |  last reply


What is the best way to power the separate sides of an optically isolated relay circuit? Answered

I am working on a Raspberry Pi based thermostat for my air conditioner and have come across a variety of pre-made relay boards that would allow me to interface with the 24v AC control circuits. Most of the boards I have found have optoisolators that separate the input side of the board from the relay side of the board. I assume this is to prevent damage to the GPIO pins in the event of a mechanical failure of one of the relays. These boards also have separate power inputs for the respective sides. I intend to use a bridge rectifier and voltage regulator so that I can power both the Raspberry Pi and relay board directly from the 24v AC line on the wall. My questions specifically is how I should isolate the power for both sides of the board. Do I need to have two separate bridge rectifiers and voltage regulators to essentially create two power buses or is there another acceptable way to protect the Raspberry Pi in the situation? Also, is the isolation even necessary in this situation? The circuit diagram for the relay board can be found at http://imgur.com/UiXmfKC. Thanks in advance for your advice.

Question by matthewsheffield   |  last reply


Traveling horizontal lines on a projector display?

I hooked up this projector at work (it's a BenQ) and when I view the projected image (in this case a computer screen) I see horizontal lines traveling up the picture. This projector is the only thing on the circuit right now.  I had to branch off the existing electrical line to add a new plug on the ceiling.  When I plug the projector into the existing outlets I get no lines, when I plug it into the outlet I installed I get lines.  The existing outlets on the circuit are all isolated grounds.  I have tried wiring in a regular outlet and then switched it to an isolated ground when the lines appeared, thinking it could be a ground issue.  I know my wiring is correct as I've installed these projectors before. What could it be?

Question by iPodGuy   |  last reply


How can I plug holes in DIY sound-isolating ear(muff)phones?

After making small holes in my Howard Leight earmuffs (probably ABS plastic) for the wires, I notice they don't isolate quite as well as before. First I tried mixing cornstarch and clear silicone caulk to make a Sugru substitute both to plug the holes and to attach the connecting wires to the over the head piece. Although the Oogoo initially seemed to adhere, it didn't seem to block the noise out, and after a few days it started peeling away. Then I tried something I had lying around for filling in damaged wood. It isolated sound very well and was very hard, but it too came apart from the plastic. Rubber cement held about twice as good as Oogoo, but also peeled away.  On the headband strap I also tried a combination of electrical tape and double-sidded tape, but it too peeled away from the plastic. Now I'm using plastic ties, which I later read someone else on here used and add an artsy touch, but they're uncomfortable. Anyone have any ideas? I've attached a Sansa Clip+ to the earpiece with Velcro.

Topic by Nat2020   |  last reply


Sorry for the outage

Our data center had a series of problems that effectively brought Instructables, and a bunch of other servers, to a grinding halt this morning. But, we're back, the problems are isolated, and hopefully won't be repeated. Sorry for the down time!

Topic by ewilhelm   |  last reply


home made graphene powder?

How can i make graphene for cheap and isolate it i try adesive tap but hoe to get graphene out of it i want to make a ultra capacitor

Question by mihir.sahu.355   |  last reply


Wiring up a filter copasitor?

For my Cold Fusion Project I was told to use a filter copacitor with the isolating transformer and the bridge rectifier.  I have had some trouble understanding this.  The mains AC runs through the isolating transformer and right after that I need to hook up the filter copacitior.  How do I know which is positive and negative.  I know AC alternates between + and - but when I need to hook it up to the rectifier I need to find + and -.  How do I do that?

Question by Kalrag   |  last reply


realistic firing mechanisms.

Has anyone developed a detachable magazine with internal follower mated to a weapon which isolates the cocking and chambering of a round? i.e. the weapon is automatically chambered when the ram rod is cocked.

Topic by the rail man   |  last reply


I am looking for a material that is thermally conductive, but electrically insulating. Answered

I need a thin sheet of this material to electrically Isolate my transistor from the heat sink without hampering the heat transfer...I tried Mica ..is there something better?

Question by vinod nicholas   |  last reply


Can I add an audio out jack to a desktop radio (stereo) with isolated left / right channels?

The plan was to add a stereo output jack and a switch to turn the speakers on/off. This way I could leave a cord plugged in and still have the option of switching the unit's speakers on or off. Anyway, a visual inspection of the circuit board shows that the two grounds are isolated from each other. The plan was to tie the grounds together and switch with an spdt between speakers and the jack, then add another set of positive leads to the jack for left and right. Now that I see they are on isolated and separate circuits, I am hesitant to tie them together. Maybe I just need to go with RCA jacks and a dpdt? I guess my real question is "am I going to blow up my radio?" Do I need to worry about dummy loads or about frying the driver circuit? I realize the audio level will not be "line-out" and I have read that a 1k resister will help, but I don't mind turning down the volume before running the signal to another amp. Thanks!?

Question by elNorm   |  last reply


Does anyone know how to bend a polystyrene sheet? Answered

 For my next project, I need to bend a 1cm thick polystyrene sheet. Does anyone know how to do this? (thermal, chemical?...). Added on May 4th: just to be sure, I'm talking about EPS (expanded polystyrene). The white isolation panels.

Question by bertus52x11   |  last reply


How to make 1:1 transformer? Answered

Hello , i want to make a 1:1 transformer for audio (guitar pedal to power amp input).Can i use this size of transformer ? and i want to re-wire it with the type of wire in the image , how many rounds the transformer need? Thanks in advance ! sorry for my bad English!

Question by login721   |  last reply


How Do you get a program to run off only virtual memory? Answered

i am trying to run this program off nothing but usb drives using the virtual memory, but i cant seem to isolate the virtual ram from the ram in the computer. How can i do that?

Question by demonspawnedangel   |  last reply


is it possible to use a low voltage controller at higher voltage?

I want to make a isolated switching power supply intended to drop and convert 220VAC to 12VDC, but the only available controllers in my area can only handle 100VDC at maximum. is there a way where i can use those switching controllers at 220VAC?

Question by codestroy7   |  last reply


I'd like to use the camera and screen from a cellphone to make a mini security system?

I'd like to isolate the camera and screen(s) from a cellphone to make a mini security system. The camera is tiny, and can capture motion. THe power usage is small. The screens are small enough to be discreet. I can use wires.

Question by    |  last reply


How to use pc817 and tip122 to control rectified mains LED array?

I have 3sets of leds that conduct at 250v so I wanted to use my 100v TIP122 NPN(with TVS diodes to protect it from over voltage) and PC817 opto-isolator to PWM the LEDs which are common cathode, is there a way? Thank you all for all the superb suggestoins!

Question by yagoa   |  last reply


request, 12vcd (automotive) to 12 vac power supply

Why?  So I can run a pile of 'pro' audio equipment on a parade float without resorting to a generator or an off the shelf 120vac (barely) inverter. The equipment I'm talking about is a pair of 4 channel wireless mike receivers (8 mikes total) and a 10 channel mixer.  Other input comes from an MP3 player or CD player.  We also have an AM/FM/HD radio on board for those long waits in parade linup.  The power amp is an automotive (12vdc) unit, 4 x 1000 watts.  Main power is a pair of deep-cycle NAPA (optima clone) spiral cell batteries topped-off from the tow vehicle via a charge isolator.  There is also an 35watt solar panel (again, for those long lineups) run through the charge isolator.  The solar panel maintains the batteries while the float is parked or in storage. Cracking open the gear we have, every single one of them uses a 10:1 step down transformer to drop 120 vac line to 12vac before dumping it into the mainboard. It looks like 12vac @ 3 amps will do it for the wireless mike receivers and mixer, but why not shoot for 5 amps to be safe? Ideally, there would be some serious filtering and regulation/protection on the output. In a Perfect & Ideal world, there would be multiple 12vac outputs each capable of 2 or 3 amps and isolated from each other. Too much for a request?  You never know if you don't ask. And, in advance, many thanks!  

Topic by snoeclipse   |  last reply


request, 12v dc-12v ac power supply

Why?  So I can run a pile of 'pro' audio equipment on of a parade float without resorting to a generator or an off the shelf 120vac (barely) inverter. The equipment I'm talking about is a pair of 4 channel wireless mike receivers (8 mikes total) and a 10 channel mixer.  Other input comes from an MP3 player or CD player.  We also have an AM/FM/HD radio on board for those long waits in parade linup.  The power amp is an automotive (12vdc) unit, 4 x 1000 watts.  Main power is a pair of deep-cycle NAPA (optima clone) spiral cell batteries topped-off from the tow vehicle via a charge isolator.  There is also an 35watt solar panel (again, for those long lineups) run through the charge isolator.  The solar panel maintains the batteries while the float is parked or in storage. Cracking open the gear we have, every single one of them uses a 10:1 step down transformer to drop 120 vac line to 12vac before dumping it into the mainboard. It looks like 12vac @ 3 amps will do it for the wireless mike receivers and mixer, but why not shoot for 5 amps to be safe? Ideally, there would be some serious filtering and regulation/protection on the output. In a Perfect & Ideal world, there would be multiple 12vac outputs each capable of 2 or 3 amps and isolated from each other. Too much for a request?  You never know if you don't ask. And, in advance, many thanks! 

Topic by snoeclipse   |  last reply


having some issues with a touch sensitive switch. ideas?

So a little while ago i had put together a circuit for a touch sensitive switch based off the 555. it works great, it senses when i touch it and operates an optocoupler from that. the issue is it senses when i touch anything electrically connected to it. im currently using a power brick to power it (supplying 5v and 12v, the switch is part of a lerger project) and if i touch anything thats connected to ground the switch activates. the part that confuses me is that theres no ground plug, just the two main AC wires. Somehow its sensing through one of those wires as well, and when capitance builds up elsewhere in the system the switch activates. as far as i know the only way for me to isolate the switch is to power it using batteries. is there any way to power it still using the power supply without it sensing things other than me touching it?

Question by zack247   |  last reply


3w common anode RGB LED circuit?

Hi all,Does anyone have a link to a circuit diagram for a common anode led? Here are the specs:Red: 2.5V ~ 3.0V, 350mAGreen: 3.2V ~ 3.8V, 350mABlue: 3.2V ~ 3.8V, 350mAI picked one up and didn't realize the effects of common anode v. common cathode :/ I can run it with drivers from one of the instructables floating around, but I have to use totally isolated power supplies (i.e. one separate battery for each color). I realize that I could use PWM for them, but I don't have the tools to program and burn a chip right now.Soooo, either a circuit that can sink current (I believe that is the correct terminology) or some way to isolate power between the 3 colors would be much appreciated.Here is a link to the led I have: http://www.dealextreme.com/details.dx/sku.4530

Topic by homba   |  last reply


Want to convert TV audio to headphone or speaker. What impedance transformer ratio is reasonable ?

Present speaker is 14 ohm. I tried a 1000 ohm to 16 ohm, it cut output to speaker by 75%. Thinking I need 1:1 transformer and probably impedance is not critical as long as it is 50 ohms or less. I will be switching between earphones or speaker. No fidelity requirements.

Question by willsonx   |  last reply


Portable Homemade TV Answered

I built a TV from an old laptop screen and one of those LCD control boards you can get from eBay but I’m curious how to go about adding a battery to it to make it portable. So, my question is, how do I go about battery safety and how do I control charging and isolation? For example, if I plug the TV in because the battery is dead, do I just have a charging board between the input and battery and let the charging board take care of the rest? And the same question is applied to when the battery is at peak charge but I don’t want to use the battery just simply plugged in. The battery is a 12v 2A lipo and I don’t want any fires. I’ve thought about adding a switch to simplify things but that’s inconvenient and armature I could make a circuit that would cut off the flow when the battery is at peak I suppose but I’m not sure of the schematics or if that is the right approach. I’m good at building just not figuring this stuff out….

Question by aniox   |  last reply


Is it possible to set the thermostat (temperature) on an air conditioner window mount unit below the factory setting?

I am trying to convert a 7' x 7' x 7' insulated room into a cooler with a temperature of 34 to 40 degrees by using an A/C unit and cannot cool the room below the 60 degree factory setting. I have tried isolating the temperature probe, but the unit just ices up. Any ideas would be appreciated. Thank-you

Question by    |  last reply


How do I separate a screen from a camer????

I want to make a pair of night vision goggles by placing a night vision camera outside the goggles, and a LCD screen inside, The problem is, I don't know where to find a camer that has a detatchable screen, I have a security camera, but it only hooks up to RCA. I don't know where to find a screen. Is there a way to disassemble a regular camera, and isolate the screen?

Question by Brakermaker   |  last reply


what could I use for.....

Hello! For a project that i will transform into an instructable I would need a color with following properties: - Stick to metal - Possible to remove using solvents - Water resistant - possibly sprayable - Protect sprayed material from direct contact with water. (not long term.. half an hour is enough.. ) - NOT heat resistant. if heated the color should be damaged and come off the metal without the use of any solvents. - must be as dark as possible any Idea of what could be used? Thanks!

Topic by sharkyenergy   |  last reply


Do i need a non-conductive material to protect the back of a bare lcd monitor from it's component?

So i've disasemble my lcd monitor and builded a new frame for it, the back of the lcd is in metal and there are two pcb's attached to it so i was wondering if I needed to add some material to isolate the component from the metal plate behind the monitor? Usually the pcb's are mounted on a plate to it won't touch the monitor directly. Thanks

Question by bluepills   |  last reply


smallest way to convert AC mains to DC 12v? Is it safe to go transformerless? Answered

When you're space restricted (like behind power boards) what would be the best way to step down ac mains (220v 50Hz for me) to say 12v????? Also, Is it safe to make a transformerless power supply? Well, its not isolated from the mains, so........... Im not so confident..

Question by pro2xy   |  last reply