Does a voltage regulator IC (e.g 7805, LM317 etc) still draw current when there is no load?
Question by .Unknown. | last reply
I am currently building an LED panel, and need some help setting up the regulators. I am using LM1084-ADJ regulators. What I was wondering is if anyone can tell me how to regulate the current, as in the math I need to calculate what resistance value I have to put between the adjustable, and Vout pins. The guy I was using simply stopped replying.
Topic by MaXoR
EDIT: Anyone Interested please check below posts, this is one is obsoleteHello!I need a voltage smoother and regulator on my circuit(attached below)it is a modified shunt charge controller circuit.It converts the Tri phase alternating current to DC and feeds it into the circuit.The regulator will have to be attachable to the BATTERIES wire in the circuit.It should not consume more than 1v power on its own.My Vout to the battery currently is fluctuating.I will need the to be a stable 12v to charge the batteries. A potentiometer will have to adjust current.I will calibrate current according to my battery bank needs.Led 1 indicates 'charging' Led 2 indicates 'Dump'And Please forgive my circuit diagram design(it looks like crap)but works like gold.Also do NOT suggest huge changes to my controller for the regulator to work. Small suggestions to make it more effective,useful like change the zener diode power rating will be welcome.P.S- Its for my hydro project.Check it out at https://www.instructables.com/community/Help-Hydro-power/Kabir
Topic by mhkabir | last reply
I need to build a unit capable of supplying a timed spark. At approx 1 sec intervals. The unit will need to be small/cheap to build and be able to supply current as to generate a timed spark across two electrodes via 240v power supply. The unit I am attempting to build is a flammable gas warning/ignition device. The purpose of it is to ignite the first immediate gas detected, as to avoid a larger detination later. The unit will be made of machined aluminum. It will consist of a vapour detector hooked to a fan unit, which inturn vents the gas to the ignition device. Thus igniting the gas. At the moment I am working on the ignition system, hence the question. Thanks for any help.
Topic by Lftndbt | last reply
I am planning to build a small gearbox that depends on a steady rpm from a 3V dc motor. I understand that the output rpms will change in correlation to the fluctuation of input power. My question is, if I used a regulator to regulate the input voltage from 5V to 3V, will that keep the motor rpms steady?
Topic by Tman179 | last reply
Today i made a shaking generator for a shaking flashlight.i am using a 5.5v 1F capacitor as storage device.but output of the generator is 3v~6v DC.how i can regulate the output ≤5v?.i am looking for most simplest and cheapest method. can i use a resistor?
Question by vina1991 | last reply
I am looking to buy or build a small voltage regulator that can fit in an O gauge electric train engine. It needs to have a 18-20 volt AC input and 10-12 Volt AC 1 amp output. I would like to buy one already built, buy a schematic or a schematic with the parts to build. Thank You
Topic by frankv6 | last reply
Hi Guys, Looking a bit into voltage regulators. When I'm looking at the wiring diagrams on the datasheets, most of them indicate that it requires a 30V+ish input voltage to work. I was hoping to get a small adjustable voltage regulator to run off the 12v range. I really don't need anything over 12volts anyway. Can I get this to work or do I have to find a power supply capable of providing 30V+ for the voltage regulator? I was looking at models such as the lm117 if it helps. Also, If I do need 30v+, where can you suggest I get that kind of power supply? I usually use 12v wall adapters. Thanks!
Question by transistorguy | last reply
I have 12 .22F 5 volt supercapacitors that i bought recently. Ive been thinking about making something like the Mintyboost from Adafruit but am unsure on how to do it with supercaps. Any help is appreciated as this is stumping me pretty well. thanks, bud
Question by budhaztm | last reply
Hi, I have put one of these together for an ATX power supply and have come across something that I might be getting wrong.... In mocking up the LM317 circuit in breadboard (standar one found everywhere on line and on the LM317 pages), I have got the thing metering -11v to +11v??? I am using one of the black ground wires of the PSU on the black side of the volt meter, but cant figure out why I am not just getting positive voltages??? Could the diode be faulty? Or is this in fact correct? Any help appreciated...
Topic by lone_viper | last reply
I am trying to power Bluetooth module and the Arduino using a 9V battery. So tried to use a voltage regulator (KA7805) with 25volt 100miro farad and 63V 1 micro farad capacitors. I checked the circuit connecting these components using multimeter, it showed 5.06V as the output. But the problem comes when I connect the Bluetooth module to this output, which turns off after quickly. I checked the voltage at the bluetooth which is reducing quickly from 5V-2.5V in a matter of seconds and since the operating voltage of Bluetooth module HC-05 is 3.6V-7V, it turns off. I am not clear why this circuit behaving this way. Same output when I connected to the Arduino, it works seamlessly. Please let me know what are the mistakes that I need to rectify for this work. Thanks in advance
Topic by Bhanu Kishan
Hi there. I have a problem for which I'd like some opinions: I have a PB laptop which has fried its inverter for the LCD due to the input voltage towards the inverter being too high (19v while it should be 12v and can only endure upto 13v). Most PB models have this problem. I looked around and some people suggest making a voltage regulator with a 7812 and some capacitors that gets its power directly from the input of the power adapter on the laptop (19v, 6+ amps). But since I am not really that into electronics, I have no idea if this will work, especially towards the heat that comes with the 7812, will it be high? The inverter needs around 0.5 amps input current. Others suggest a setup with (zener) diodes, but I have no clue how to start on that. Anybody have a suggestion? Many thanks.
Topic by .conne.
I am new! I am New! And when I say new I mean I am 40 years old and only recently embraced the computer and thuslynthe intro-web. Although my embrace of said tea is like those crazy hugs where people kind of stick their buts out and break off quickly. Don't think I am some guy that has lived under a phone book all my life. I have used computers before but never in my spare time. so forgive me if what I am looking for is simply found. The reason I ask is I "did" belong to an interesting site but I am on restriction for recommending a different web site. The web site was not even in the same field but anyways. I am really digging this site and don't want to screw it up. Like right their I do use more colorful language from time to time.. Thank you for your time.
Question by AlexD164 | last reply
Hi all, I've got a laser diode, with the following specifications: "Wavelength:808nm Power Output CW 500mW Working Current: I<350mA Working Voltage: 2.2V" And a laser diode driver: "1. Constant current Stable voltage IC circuit, laser diode can be better protected without being damaged 2.Constant current output , Can be adjusted（0~580mA） 3.DC supply voltage input 3.0~4.2V. 4.Suitable for 808nm 100mw~500mW laser diode." The combination of these two things will be switched on and off by an Arduino (Probably using a relay, as the driver board has a switch connection) - This may change but I don't imagine this will matter. ---------------- I noticed that the 'DC supply voltage input' says 3.0-4.2V . My power supply will be 5V (I don't imagine that Amps matter but if they do, it has a max output of 34A). What would the best/safest way to do this be? I don't want to burn out my laser because they're comparatively expensive, and I'd like it to be able to run relatively continuously (Probably multiple-minute continuous usage) (For those of you wondering, I'm one of the many people making a laser engraver/cutter from scratch)
Question by jonrb | last reply
I was wondering I'm making a very tiny project with that requires 5v. I'm using these little 3v batteries (CR2016). If I use like 6 of those and a 5v regulator, approximately how fast will they drain? Is that not a good way to lower the voltage?
Question by HavocRC | last reply
Can I use a Co2 regulator to regulate high pressure air. I am trying to build a high pressure system using a scuba tank or paintball/airsoft tank to operate air tools, pressurize pipes, fill tires, inflate balloons, dust work areas and computers, etcetera. There are C02 regulators but not many 'air' regulators. I just want to use air and not Co2.
Question by RandallIja | last reply
So what I am trying to do is make a variable power supply from a computer PSU, I've done thise before minus the variable part. I need a voltage regulator that will limit 200 or more volts to 100 volts DC. I also need different variable voltage regulator that will allow me to adjust this from 0 to 100 volts, they usually have a circuit in the datasheet that uses some resistors and a potentiometer. So, are there voltage regulators like this? If not what is another way to do it?
Question by XOIIO | last reply
I need a 3.3V for one of my projects and decided to scavenge one from an old Arduino clone I had lying around. Only problem is I can't figure out where the 3.3V regulator is!! The board has a 3.3v pin and I've also measured a steady 3.3V output using a multimeter but all I can see on the board is a 78M05 and a diode. I've uploaded a picture of an original Arduino Uno board I have for comparision. The 3.3v regulator on that one is pretty easy to find. Any help in finding the 3.3v regulator will be appreciated. Thanks.
Question by newbie007 | last reply
I need to power one of my projects for which I need a power source. I require 6V,which will require a lot of batteries. So, I decided to make a regulator and supply it through my 12V DC transformer. Please if any one of you can give me a schematic of the same I will be gratefull.
Question by pranjal12 | last reply
I havea spare USB hub and it's not used. I wanted to take it apart and take the regulator out of it. It has a part number: PJ1084/CM 1B1. After Googling the part number I've found that it's a 12v 5A regulator, why? The mains adapter with it is only 7.5v, so where does 12V come from, the only thing that I know is 12V is the PS2, and this is definetly not for that.
Topic by Josho | last reply
Im planning on building a motorized trailer dolly for my travel trailer, however i want to make a dead mans switch for the trailer brakes. I was wondering if I took apart an old cordless drill if I could use the trigger as a voltage regulator to regulate the voltage to the trailer brake system. Without getting into specifics of how it will connect to the regulator, I figure I would have like a bike brake handle that while applied the trailer brakes would be off, but if released that the trailer brakes would be applied incase the trailer started to roll away from you. Any suggestions other than "Go buy a trailer brake controller" would be appreciated! :)
Topic by Thunderbone | last reply
Does anyone know how I can get (or make) one of the regulator / valve things that screws on to a disposable oxygen tank? I would use the regulator from a propane torch but it has to have left hand threads. All the ones on Google shopping and Ebay cost like $40 and I realy don't want to pay that much, I'm thinking more like $10 or $15. I could use a Nitrous Oxide dispenser like the ones used for making whipped cream instead if anyone knows how to get or make one for the same price.
Question by Jaycub | last reply
I have a xj600 pre div, been stood for few months, I started her up other day and after ten mins ticking over I noticed the wires coming from/to the regulator/rectifier started to burn....What could be the causes??? And what can I do To fix please... Thanks....
Topic by AlanW131 | last reply
Ah, voltage regulators. Easy Right! Not this one. I am making a voltage regulator like for an automobile regulator for a DC generator. (I'm replacing the old DC generator regulator on Pre 60's cars) A battery is charged from a winding on a Generator (20V @ 60 Amps) A voltage sensor on the battery voltage turns on and off a switch driving the Field winding. The Field winding basically "turns on and off" the generator output. The battery is connected directly to the generator. (Why and Why not is coming up) But when the Genrator's output is lower than the Battery voltage, current will flow back from the battery to the generator winding and discharge the Battery. So I need some isolation between the generator output and the battery. Alternators are easy since it has a bridge onthe output keeping the current from flowing backwards. Old regulators used a relay which burned out sooner or later. So easy, use a diode right? Just put a diode inseries with the generator to the batery. By the way, the "open circuit" voltage on a generator is about 200VDC No! The best diode I can find has a .7V drop at 60 Amps which is 42 Watts of heat to dissipate. Ahhh, so use a FET, They can get down into the milliOhms right? Except for the reverse polarity (and ESD) protecton diode always across the FETs defeat the purpose of a reverse polarity switch. So who out there is smarter than me? What goes inthe box marked ?? Any solutions accepted. Ungefahrt (now neither young or fast)
Question by ungefahrt | last reply
I have a 16 gb Ipod Touch and I wanted to be able to charge it from an old laptop battery that is 14 volts. I did not like the idea of using a 7805 because it is so wasteful, so I was thinking of using a switching regulator like this one because it has an efficiency of 85% @ 14 volts. http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name;=LM2591HVT-5.0-ND Something in me is just worried that because its switching on and off really fast to achieve the voltage that it will not work for charging my Ipod, so I came here to ask "will it work and is it the best option?"
Question by flybye22 | last reply
How exactly do I hook this up? Where does ground go? Where does the Vin and Vout go? This is the circuit but we're replacing the 7805 w/ the boost regulator. Thank you!! The pic of the circuit isn't showing up - the circuit goes: Coil /w magnet connected to diode bridge to capacitor to 7805 connected to the cell phone charger. We're replacing the 7805 with the NCP1402 - do you know where it goes? Thank you!
Question by mckywer | last reply
Currently i am working on a 12V solar panel. the solar panel will be charging up the battery of 12V7AH. The problem is that by using the solar panel,the voltage often to be fluactuating down until 10V. How can i make the voltage remain constant at 12V?
Topic by haizad86 | last reply
Hi everyone! I have a dynamo on my bicycle which can generate AC 12v-30v during normal to fast cycling. I want to power electronics and charge batteries with the dynamo but do not know how to limit the voltage to around 12v DC. Any help would be greatly appreciated.
Topic by sirajmunir | last reply
I have built a solar panel as a fun little project, now it has come upon a big problem. The solar cells that I am using seem to have a higher amperage output and a lower voltage output in high intensity sun while having a high voltage and low amperage output in medium and low intensity sun. This poses a problem as my batteries were able to recharge during late winter and early spring but now are not able to recharge when there is the most energy to be captured during the summer. The average voltage during high intensity is about 11 while the voltage during medium or low is around 12.5 and 13. I want to know if there is a way to create a transformer to step up the voltage or create a voltage regulator that can withstand 13 amps so the battery can recharge properly. A link or any suggestions would help.
Topic by menace
Hi, I'm trying to make a DC - DC voltage converter. The real purpose is to power an old USB hub in a car. This is because so many of my electronics these days use USB to power them and rather than have a nasty mess of car power adapters I want to use a single 12V supply for the hub and then plug all of my goodies into it. Now for the meat of the question..... What is the best circuit design for using a voltage regulator. I have looked at some stuff in data-sheets and it just seems way too simple. The part I'm looking at using is a National Semiconductor LM1085-5.0. Input voltage 6.5 - 20V output 5V max of 3A
Topic by Sailing_Nut | last reply
Hello!! I need some help here...I am very "green" when it comes to alternative energy, so bear with me please! I recently decided to put together a small wind generation system to power my workshop. System is comprised of a 38v Ametek PMDC motor, 6.8' tri-blade array for propulsion. I also intend on installing a 2000 to 3000 watt modfied sine wave inverter powered by my battery bank to provide AC voltage to the shop. I want to be able to used the majority of the power created by my wind generator. I understand the concept of using a "shunt" but do not have a need for hot water or useless lighting. My question is this, would the Flexcharge NC25A charge controller (www.flexcharge.com/flexcharge_usa/products/nc25a/nc25a.htm) be sufficient enough to used in this system? Or is there something else out there that would maintain my battery bank without shunting the load when the bank is fully charged....Thanks in advance.
Topic by NMCBDet23 | last reply
My understanding is that they're very similar to regular LEDs, but LEDs only need a resistor. What makes laser diodes so special? Are there circumstances under which laser diodes don't need a full driver circuit?
Question by jonrb | last reply
I am making a project using an alarm clock, and basically for this part, I am trying to make the alarm turn on an array of leds and I have it working, I have the voltage regulated right and everything, I just need to know how to make the leds stay lit instead of turn on and off with the pulse of the alarm... I thought that I could do it with a capacitor but I haven't figured it out yet... Thanks
Question by arhodes18 | last reply
Lm7805 http://www.sparkfun.com/products/107 7805 http://www.radioshack.com/product/index.jsp?productId=2062599#
Question by Munchys | last reply
I've recently had two gas questions arise. Both issues need a gas regulator that I am not sure of what type, or pressures needed. The first a a L.P.G bunsen burner I bought off ebay. The second, I have a gas furnace for smelting that connects to L.P.G Can someone give me some help on what type of regulator I need for these? Also maybe a bit more info on how to connect the bunsen burner up to the gas bottle, regulator, to a switch valve, then the burner. I have seen low-pressure regulators about as well, can this work for the bunsen burner
Question by AtomRat | last reply