Hacking a Liftmaster solar gate controller system

I have a solar powered gate, using a liftmaster system. The main control box cannot have a power input above 12 dc at 30 watts. I need to be able to control the power input to about 25 watts. Due to the environment in which the system was installed, I had to use solar panels and batteries that have a higher output than 30 watts. How can I keep the volts to about 12 volt and keep the watts under 30? I tried to google adjustable amp regulators, and the answers are not clear. How can I find an adjustable amp regulator for my specific needs?

Question by charliemmann1975   |  last reply


Where to get piezo igniters?

I have several lighters that I still like, either for their design or intended purpose. But over the years some failed to produce proper sparks with the piezo. For some I could salvage replacements from cheap lighters but not so much for the longer ones - the type to get your bbq or oven going. Here the wire from the igniter is in ne long piece going all the way from the piezo, through the long neck to the flame outlet. As the wires in those piezo igniters are aluminium it is next to impossible to attach a longer wire as usually there is no room for crimped connections and the isolation is a problem too. I also have one particular lighter that uses a slightly longer and thicker piezo igniter, the common ones don't work here as they are too short. Adding more support underneath is a no go as the shorter ones have less travel when activated. Last but not least is one lighter that requires a piezo with not just the little metal cap at the end but with a full metal body for the stationary part. The lighter in question does not work with standard types even if I add a little metal strip to make proper contact. Problem is simply put that like this the standard ones arch over and no spark comes out of the wire. So big question: Is there any supplier or Ebay shop where one could actuall see the various types of piezo igniters and order them in small or single quantities? So far I already struggled to find a source for the crappy standard ones and the only one I found wanted to charge $ 2.95 US per igniter plus postage. Sounded a bit greedy to me considering I can buy a complete lighter with it for around one single buck...

Question by Downunder35m   |  last reply


My Hydrochloric acid and Hydrogen peroxide etchant goes red without any copper in it. How come?

I recently tried making acid cupric chloride etchant; however, my batch always goes a darkish red colour as soon as i mix the two together even when i haven't added any copper. I've been using 3% hydrogen peroxide from a pharmacist and 30% HCl From Bunnings. All the stuff was fresh and in dark plastic bottles. The container i put it into is plastic. It still etches but it's nearly impossible to see if the copper is etched away without pulling it out. Can anyone tell me what's in the mixture that's making it red and how i can correct it. Thanks

Question by Lost in Translation   |  last reply


My laptop won't connect to our wireless router?but other computers will? Answered

So a few days ago my computer disconnected from our wireless router which im used to this happening so i just let it go i figured it'll connect again just like before...and now a week later it still doesnt connect. So far i have tryed doing a system restore, updated my wireless card drivers, and have done an automatic update from windows. Still doesn't connect to it at all so im lost..any ideas as to what is wrong or what i should do? im running windows 7 intel i7 and a intel wifi link 5100(i believe thats what it is?) and if you need more info let me know.

Question by tubanator-2.0   |  last reply


movie ideas anyone??

Hi I'm a filmmaker (i work for Stop Motion Pictures) and am really looking for movie ideas because right now I have nothing! I have movie making block. Any idea I choose to use you will be credited. It will probably not be made in a while I'm working on getting my camera and tools. Please share any ideas! Even stupid ones!

Question by amakerguy   |  last reply


corrupted rar file? Answered

Hi, I have a rar of which WinRAR says that the CRC is wrong, and the file is corrupted. I allready tried to "keep broken files" when I extract, and I allready tried to repair the file. It doesn't works. What can I do to extract .rar archive? Thanks in advance.

Question by altenabaste   |  last reply


Why is my electro magnet switching on and off?

I've recently built an electromagnet with a DC power supply off 5v 4a but when I turn it on it goes on and off . I'v checked this by downloading a sensor on my phone and surely enough every second the magnetic field goes higher than my phone's range and then returns to normal can you please explain why and how to keep a constant field

Question by charlie30122004 


LM35 temperature sensor on nodemcu esp8266

How can I just get 1 decimal instead of to using Arduino IDEhere is output from serial monitor in DegreeC= 25.24a part of the code int analogValue = analogRead(outputpin);float millivolts = (analogValue/1024.0) * 3300; //3300 is the voltage provided by NodeMCU float celsius = millivolts/12; Serial.print("in DegreeC= "); Serial.println(celsius);

Question by NenneD 


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


How can I turn an air conditioner on/off without remote.

How can I can I modify an air conditioner so that it can be turned on/off without the remote as soon as I turn on the power switch? I however want to use the remote to regulate the temperature.?

Question by cprompt7   |  last reply


How long will a lithium battery store? Answered

If I bought 2 rechargeable lithium polymer batteries for a cell phone, but only needed one for now, could I store the unused battery until the first battery quit charging (and was garbage)? If the above question makes ZERO SENSE, let me try explaining it another way: Ok, you have this fancy gadget that you want to keep functioning for many years. Eventually, the battery inside won't be able to take a charge, and the battery will be obsolete and no longer sold. Would it make sense to buy extra batteries ('stock up') and store them for a time when the original battery went bunk; would the stored batteries be like brand new after many years (these batteries would have never been charged before.. they would be still originally packaged)? Hope that actually makes sense :D -Neph

Question by nepheron   |  last reply


How to magnetize new refrigerator door gasket????

Refrigerator door gasket came unmagnetized. Very expensive, and, royal frustration thus far. Got the thing installed okay, but there is no 'seal'. Supposedly, according to Whirlpool, they don't need magnets in the fridge door gaskets to seal.....(Yeah, right) Any way to make a gouzer? Figured I could depend on help here. If I had enough magnets, I'd make my own. Also, why are the gaskets on the door?

Question by littleangels   |  last reply


What pins do i need to short on a dell battery to get voltage? see details for what i have already found please?

Ok, so my though was to take an unmodified Dell battery (11.1v), attach an iPhone car charger to it and use it to power my phone without having to buy a commercial battery. Plus I can put it in my notebook to charge it. Last night I was using spade connectors to probe for voltage, but all I could find was 3vdc, not the 11.1vdc it is rated at. So I poked around some other sites, and found one where a guy used a notebook battery for a robotics project, and that certain pins had to be shorted to make the battery "activate". So, I then probed the connector on my notebook (the one the battery is from) and found the following: There are 9 pins on the notebook side. Pins 1, 2 and 4 all have continuity between them. Pins 8 an 9 have continuity between them. On the battery side, I get 3vdc between pins 1 and 4, 2 and 4, 8 and 4, and 9 and 4. My question is, does anyone think i will get 11.1vdc on another pin on the battery if i short 1, 2 and 4? Unfortunately I cannot open the battery because it is a spare I wish to keep around, but still would love to use this.?

Question by abuthemagician   |  last reply


How to add magnets to magnetic resistance exercise bike to increase resistance?

Hi, and thanks for reading my question.      We have just bought an exercise bike, it uses the pedalling to power the magnetic resistance of the bike. Here is the problem: at the highest setting, the resistance is still not very much.  We think that maybe we can increase the resistance by putting a strong permanent magnet near the flywheel, (we would cut a hole in the plastic cover to put the magnet near the flywheel). Can someone explain how to figure out how strong a magnet would need to be? How much "pull" would probably have a significant effect? What type (neodymium?), and what shape would work best (disk, rod, etc...?). We are willing to put about $50 into a magnet.   If this doesn't work I think I will remove the cover and just use a "friction wheel" sitting on top of the flywheel. really ugly, but it should work. Thanks for any help you guys can give!

Question by Urrgghh004   |  last reply


36v ebike battery to 12v kayak motor

Hi. I have bought an e bike with a 10ah 36v Li-ion battery pack. Can I use this to power my 12v kayak motor? I have the kayak set up with a pwm currently to control the speed. Do I need a converter to lower voltage. Or can I just use the pwm? Advice please.

Question by jonclark80   |  last reply


How do you inverse the function of a LDR (Light Dependent Resistor) ....? Answered

I know the schematic diagram ... But I don't know how it works ... please can someone explain me the inverse function of a LDR I've posted the schematic diagram also! Thanks

Question by harshesh   |  last reply


Help with an SMD circuit

Hello. I am trying to make something on my car that involves putting an array of orange SMD's in a big circle, one on each side of the car. Every circle has about 85 ish SMD's, how should i connect resistors,and which ones? Can i put them in groups of 10, and put a resistor between each? I have to conect them parallel. Thanks for the help

Question by dsirotic   |  last reply


Is it possible to charge a mobile phone from a lemon? Answered

Im thinking, lots of electrodes in one lemon, joule thief and a capacitor maybe...?

Question by dalbyman   |  last reply


walkie talkie circuit diagram?

Pls I need a simple circuit diagram of walkie talkie that I can use for my project with detail information. details and circuit can be send to my mail: enochaj@yahoo.com Tanks

Question by Jiya Adama   |  last reply


Expected unqualified-id before 'void'

I m facing a problem in this code during implementationi m using wemos d1 r1 controller board.i m attaching a code.the error is webtwit:52:1: error: expected unqualified-id before 'void' void setup() { ^webtwit:49:16: error: expected constructor, destructor, or type conversion before ';' token timedRead(void); ^exit status 1 expected unqualified-id before 'void'please help me to resolve this query

Question by nazni 


I mistakenly put the gasoline i used for my weed wacker (Gas and oil) in my mower and it doesnt run very good now.

I have changed the spark plug a couple times and it is pretty dirty with carbon. I even tried carbuerator cleaner . It has no gas filter

Question by    |  last reply


Can you run an electric motor off solar panels and in turn produce more electricity than the solar panels can???

I want to know if it is possible to run a one horse power electric motor 120 volt off a solar panel and in turn it runs a generator that would produce enough electricity to make a difference on my bill. The solar calculators say I can only save about $60 a month.... off my 3 to 4 hundred dollar bill. The motors I am talking about is the type used for turning water pumps ... they last for years...   

Question by inquestof   |  last reply


How to heat up nichrome wire?

Question by MrX5   |  last reply


Power bank

Hello everyone I recently found a 12v 9a.h battery in my stuff and now i decided to make a portable power bank with it.this is what i am thinking about:i want to make a portable power bank with several voltage outputs for using in car and etc. 1- I want to get a 5v output and use it to charge my devices when I am in a car.2- i want to connect some power led lights so that i have a light bar.3-maybe I also connect an amplifier to it to play music when walking or etc.now that you understood what i want to make these are my problems:1-when the battery slowly drains and the input voltage decreases will the output of the charger module also decrease?2-different devices need different currents for charging for example my tablet needs 2amps while my phone needs 1 amp. do i need to set the output current to any special value?3-what kind of solar panel will be suitable to charge the battery?

Question by Electronic guy   |  last reply


What is the optimal and minimum voltage to charge a 12v 9a,h battery? Answered

What is the optimal and minimum voltage to charge a 12v 9a,h battery?

Question by Electronic guy   |  last reply


Circuit help

Been decades since I did any circuit design and I have a fairly simple need someone will certainly have a simple answer for.I need to run a simple pulse output from a 5 minute timer into a circuit that will have 4 outputs. Each pulse in will cause the next output in line to go HI, with the others all LOW. 5 minutes later, the HI will move to the next Output, with all the others again at LOW. Once the 4th and last output has gone HI, it will wrap around to the first output again, and so on. Sound a bit like a Ring Counter, but there is no CLOCK pulse here. Just a short pulse every 5 minutes or so to the input. Any help would be appreciated. This isn't rocket science, so simple and cheap would be a plus.Thanks.

Question by gjforeman   |  last reply


How to determine what size Audio Potentiometer is needed? Answered

Second attempt to get this question to publish.....sigh... In a small project with approximately (1/4 watt) .25 watt audio output into an 8 ohm speaker, what size Audio (I assume non-linear for audio) Potentiometer should I purchase? I tried a 10k but either I got a Linear (from what I've read) or 10k is too large. When adjusting to volume, I get nothing for most of the turn and then I get all of the volume. I can adjust to the volume I need, but it's very oversenitive. I would like it to gradually adjust the volume. Thanks

Question by keydogstony   |  last reply



Ammeter on bluetooth speaker

Hi,I'm building a portable bluetooth speaker and need some help. The speaker is equiped with a TPA3116 amp and is power supplied by a 3s lipo battery. On my construction I would like to attach an analog Weston 301 ammeter in order to check my battery's life. Is it possible? The ammeter can measure 0-15A and the battery is 10A. I made an effort but when I attached it on th battery there was a spark.

Question by VassilisT   |  last reply


Add stereo headphone jack to an exercise bike with hardwired on-board stereo speaker pair

I want to add a stereo headphone jack to an exercise bike with a pair of hard-wired on-board stereo speakers. I imagine each speaker has 2 wires going to it. Is this as easy as taking either or both ground wires and the two signal wires and wiring a 3.5 mm TRS jack? How does a connected headphone typically turn off sound in speakers? How do I handle the two ground wired (one going to each speaker).... can I just use either? or if combining grounds, do these need to be electrically "isolated", if so how?Thanks in advance.

Question by ipaulshapiro   |  last reply


DIY/Open-Source multicamera sensor module build??

I'm trying to figure out how to DIY a multisensor camera similar to "https://www.wired.com/2015/10/light-l16-camera/". Using multiple camera modules to take a picture then stitch them together to create a higher quality photo. I can't seem to find anything close enough except for multiplexing raspberry pi camera modules and I want to stitch the images together. I don't want to be limited to using just raspberry pi in case it's not powerful or fast enough to stitch multiple images into one.

Question by Shawn Nguyen   |  last reply


Why is there no "posted on" date?

Hey in my instructable Smart-Distance-Measuring-Tape-v2, I dont see the "posted on" date. I worked hard on this instructable and it din't get featured, so I commented on the clinic, where Ben Finio informed me about it. I think that may be a glitch and could be the reason why my instructable did not get featured.

Question by ThisIsSteve   |  last reply


Can I change resistance values in laser diode driver circuit to be able to use it with another laser diode?

I have Laser survey units,tens of them, each has IR original laser diode with this specification ((Ith= 17mA, Iop= 31mA, 798nm, Im=1.26mA)). This laser diode is not available any more, I used to use a Sanyo replacement for it DL3144-008S with ((Ith=25mA, Iop=30mA,785nm,Im=2.0mA)). The driver of laser diode is attatched, Iused to change the value of series resistor with photo diode to adjust the output power and it works great. Unfortunately the new LD is also not available now the available one for me is 9GAIA red LD(ADL-65o55TL) with ((Ith=18 to 25 mA,Iop=25 to 35mA,655nm,Im=0.12mA)) the beam is very dim even with current 35mA!!! does it have any relation with monitoring current which is very low in the new one and if it has, if someone can advise me how to change values of the resistance to let the driver work with the new monitoring current, and if it is something else kindly adviseThanks

Question by laserplane   |  last reply


I want to manufacture radiator coolant for vehicles. Pleae tell me the process.

In ur ans in yr 2010 u ve mentioned about the dye.. what kind of dye is requierd ?? 

Question by arcbits88   |  last reply


How do I edit my comments? Answered

I want to add a link into a comment I posted. Is this possible?

Question by PatYoungers   |  last reply


Need help with arduino code.?

Alright I asked this question on the arduino forums but nobody is giving me a straight answer, and it's getting annoying. I am using the capsense library on an attiny85, I want to count the number of times an even happens, in this case the capacitive censor exceeding a certain amount. Then based on that number I want it to turn on one led, or two, and so forth, to keep count. Can someone tell me how the f*****g get this to work? I try to use serial to debug and just get "Serial" not defined in this scope. Heres the code: #include #include CapacitiveSensor   cs_1_2 = CapacitiveSensor(1,2);        // 10M resistor between pins 4 & 2, pin 2 is sensor pin, add a wire and or foil if desired int ledpin = 0; int countnumber = 0; void setup()                    {   cs_1_2.set_CS_AutocaL_Millis(0xFFFFFFFF);     // turn off autocalibrate on channel 1 - just as an example   pinMode (ledpin, OUTPUT); } void loop()                    {   long start = millis();   long total1 =  cs_1_2.capacitiveSensor(30);   if (total1 < 99) {    countnumber == 1;   }   if (countnumber = 1) {     digitalWrite(ledpin, HIGH);   } }

Question by XOIIO   |  last reply


Control of 25 electromagnets

Hello Everyone, I'm looking for a controller to manage 25 electromagnets. I've managed to come up with a driver circuit to energise each individual electromagnet using an N channel eMOSFET in parrallel with a diode. I need a programmable controller to operate the gate of each eMOSFET but the controller must be capable of managing all 25 switches. thanks for any suggestions in advance.

Question by wameri   |  last reply


How can I figure actual power consumption for my kiln, without buying a wattmeter? Answered

I'm working on some fused glass projects for sale, and I'm trying to figure my kiln's electrical consumption into the price of the items as accurately as possible. I can easily figure the max draw of the kiln, but it's not running full tilt throughout the whole fusing cycle. In fact, through much of the cooldown phases, it hardly comes on at all. I don't want to grossly overestimate and gouge the customers, but I also dont want to underestimate and lose money on the sales. I also don't want to buy a 220v wattmeter that I'll never use again. I don't need super-precise measurements, just reasonably accurate ones. Is there a feasible alternative to a wattmeter for this application?

Question by RavingMadStudios   |  last reply


Arduino NANO error uploading sketch. After attempted loading of NANO clone (ELEGOO) the IDE hangs -

The Com port was selected, old bootloader selected. Various error messages (will collect and add to post here). However the very strange thing is that the NANO is sending to the Serial Monitor at 115200 BPS the message"Loaded next response 1" continuously!OS is Win 10 64 bit - current version with all updates.USB Driver is USB Serial CH-340 version 3.5.2019.1 dated 1/30/2019.This appears to be a new issue that appeared after I attempted to run two instances of the IDE with two NANOs attached. One on COM4 and the other on COM11.I have deleted and reinstalled the driver - same issue.Going to try on another PC.Anyone have any ideas?

Question by Rozzer   |  last reply


Crystal walkie talkie range extender? Answered

Hey everybody, I'm modifying some old walkie talkies I have, and I want to extend the range but I'm not sure how to do it, though, because it uses one of those crystal transmitter components to output 49 Mhz. If someone knows how to extend range on radio crystals please let me know! Thanks in advance!!

Question by Adum24   |  last reply


BLE Beacon finder, how to ?

Hi everyone,I am mechanical engineering student and haven't expertise in difficult circuits, so I am here to ask for your helps guys!I am working on a personal project in which i want to create the smallest BLE Bluetooth device possible which could be charged by induction. What i want is just to connect this device to my smartphone.I did some research and i came up with the following components : Qunqi-HM-11-Bluetooth BLE (1.7 V to 3.6 V) Rechargeable Lithium Battery (3V or 3.7 V ) TP4056 Lithium Battery Charger (5V, With micro USB) Wireless Charging Module 5V/300mA (SKU:DFR0363 Brand:DFRobot)So my questions are : Is the TP4056 required to charge with the wirless charging module ? Are those compnents can work together ? Is it possible to make all those components in one PCB by designing it ?Thank you very much,Nabil

Question by dzproject24 


which is the positave terminal on a dewalt 18 volt battery?

Dewalt battery terminals are not marked, I need to know which is which

Question by popop1111   |  last reply


How do i increase the speed of an electric bike?(Motor in hub)

I know you need to increase the power going into the motor. I don't understand exactly how? I know that a different battery with higher voltage output should work, but is there any other way? If so, how and what would I need? I trust that you guys can come up with something. P.S I am aware of the potential danger of the motor if I increase too much.

Question by ClaynEva   |  last reply


I need help identifying a part Answered

Somebody gave me a box full of speakers mids, highs, woofers, and tweeters... In that box also came 2 of these small circuit boards with 2 knobs attached to them... Don't know what they are, and what they use for. Any help will be appreciated

Question by Kingsup310   |  last reply


Power supply recommendation

I've been trying to collect info and guidance on how to build a portable and minimalistic power supply. I have in the past built other stomp boxes and small amplifiers (PCB kits) but never enough to learn how to read schematics or build from scratch, so I'm looking for something pretty detailed or simple enough. List of the technical and practical requirements: -Steady and safe current output for several hours straight; -Operating voltage: 3-4 to 15-17 volts; -Current: 2-3A; -1 voltage control potentiometer; -1 digital voltmeter; -1 output (1/4 jack); -1 pedal switch input (1/4 jack); -1 status LED; - Possibly external transformer (to keep it smaller and avoid overheating); -No vent holes; I have found similar builds (instuctables and YouTube), but never similar enough to be sure that putting that build in a smaller and sealed box would perform well and not overheat It seems weird to me that I wasn't able to find any kit or project for such a simple build. Below a link to an ideal result example https://thelondontattooconvention.com/suppliers/hard-craft-company-handmade-tattoo-power-supplies/

Question by circuitcircus   |  last reply


how to make an inductor?and how much it (uH)? Answered

I want to make a flyback driver, i need inductor 200 uH

Question by Rendydevara   |  last reply


Capacitors, where to get them? Answered

For a school project, Me and my friend build a medium sized railgun, however, we can't keep the capacitors we used to power it. My question would be, Where can I get some capacitors to replace the used capacitorbank. I am looking for capacitors with both a high voltage rating, and a large amount of capacitance. (the total bank contained 8 1000uF, 385 volt capacitors, I would like to get at least half of this out of my replacement-bank) so does anyone know: places where I can buy this kind of capacitors for a small amount of money, which do ship in europe. common used electronics containing this kind of capacitors to salvage. I already found some in a computer PSU, one in a computer monitor. And I know they are used in disposable flash cameras, which are not very much used any more, and can hardly be found here (Unless I buy them, which is going to cost me a very large amount of money) Places where those capacitors are commonly used, and where I might get them for little money. They don't actually need to have the exact same voltage and capacitance, but I would prefer them to be somewhat close to it. ( > 100 uF, > 100 Volts) I am also looking for a new charger. chargers from disposable cameras might work, but tend to overheat and break down rather fast, I would like to know if there is something better.

Question by kirdaiht   |  last reply


Project idea for artificial lift

Hi Team,I want to develop a prototype of Artificial liftThe requirement of my project is that it should be based on arduino.Till now, I have thought of having a robo car which will have a robotic arm and attached to it will be linear actuator.The robo car will help me go to the well, robotic arm will be above the well and linear actuator will go inside the well and measure temperature and humidity and come backThe problem is that I am not able to get all the things and attach to each other. If I get a robo car, then I will not get a place where I will attach robotic arm.Kindly help me and also suggest me some ideas. I have bought a meped mechanical spider.Thanks & regards,

Question by jhaamit6666 


Battery support with Intel Compute Stick

Hi, I've been working in a project that is basically an Intel Stick with Z8350, a 7 inch waveshare screen and joystick buttons in the case. The idea is to be able to play windows games like Skyrim, Borderlands, Fallout... Anyway, I've come to a point where everything works just fine, right now I'm designing a 3d printed case to fit it all inside and take it to the go. I was planing on using a battery meter with LEDs to know the charging state and current state of the battery, but I just have been wondering, is there anyway to add battery support with windows 10 reading? just like a laptop, you pop a battery and windows gives me the percentage left and charging status. I plan to post a instructions for this when I finish it as well with the 3d print files and part list. My thanks to all!

Question by deadlyredink 


I have usb cables, and AV cables. Can I just splice them somehow to connect VCR to Computer?

I want to convert VHS tapes to DVD's.  There is freeware to use if I can get my signal to computer.  AV / USB cables are expensive.  Is there a way I can splice the usb and AV cables I have to do this?

Question by Mhbaben   |  last reply