Modifying a DC-DC boost circuit

I'm building a circuit that would run off roughly 7v and convert it to 12v using the LM2577 (LINK). the datasheet (LINK) provides an example circuit that will output 12v @ 800mA. I need a little more power than that. around 1.25 A. my question is that if the 100mH inductor was replaced with a larger one. say a 150mH one, would that increase the current output? i would also replace the 680uF cap with a bigger one to reduce ripple. FYI the LM2577 is rated to convert 3.5v-40v to 12v. any information or direction would be appreciated picture is from the national semiconductor datasheet page 3

Question by stapler117 8 years ago  |  last reply 8 years ago

Circuit Design for DC to DC Buck-Boost Converter

Sir, I am Anand from india, I will made a project based on bicycle. I have take 5 to 80v From my Bicycle pedals. Generator power is in AC 3-Phase. I want to made next step. in this I want to this 3-Phase AC 5 to 80V are constant At 48V DC. I put the 4 batteries in series. 12V 20Ah battery I use. I want to charge this batteries please help me. Thank you.

Topic by AnandC10 3 years ago  |  last reply 2 years ago

Circuit Design for DC to DC Buck-Boost Converter

Sir, I am Anand from india, I will made a project based on bicycle. I have take 5 to 80v From my Bicycle pedals. Generator power is in AC 3-Phase. I want to made next step. in this I want to this 3-Phase AC 5 to 80V are constant At 48V DC. I put the 4 batteries in series. 12V 20Ah battery I use. I want to charge this batteries please help me. Thank you.

Question by AnandC10 3 years ago  |  last reply 3 years ago

Overheating mc34063 as boost converter Answered

I've been using the mc34063 in boost converter manner to build an external battery circuit for 3.7v->5v DC-DC conversion, but within few minutes of operation the chip and the inductor begin to overheat beyond touchable (light smell of burning components too), occurring with both circuits that I had. I've tested using the following devices: ipod touch 2G, ipod touch 5G, kross g6 tablet, all of which had the circuit overheat. The power source is 4 cylindrical cells in parallel @ 3.8v ~9A with protection circuit. The batteries do not overheat and I'm guessing the protection circuit regulates the current to an extent. I've tested the current draw of the ipod 5G to 100mA while the circuit is wired for 500mA. This is what the schematic looks like: I would like some help in troubleshooting the overheating of the circuit, Thank you.

Question by Ahyku 4 years ago  |  last reply 4 years ago

9V Solar Cells (Parallel) to DC to DC USB Booster: Will it "fry"?

Hi all. Here is my question. I want to take 3 Solar Cells (9V, 500mA) wired in parallel (1.5A output) and run them through a DC to DC USB Boosting Circuit (5V) Now I know this circuit will boost up to 5V, but what if 6-9V comes in to it? Will it just limit to 5V running through, with no boost, or will it "fry" it? One more question: What if I wanted to have the 9V, 1.5A of the parallel solar cells route into a Mini-USB port that can take 2 amp in? Same problem, or no problem? Any help is appreciated! Thanks!

Question by yamata45 6 years ago  |  last reply 6 years ago

Boost 12 V lead acid to higher values, like ca. 60V (+- 30) for amplifier...How?

"home" amplifiers are relatively easy to find. A simililar amp can be built from available (velleman) kits, or from discrete components.  But for portable use (on the bicycle, or car) , with one, or max. two 12 V batteries, only ready made car amps are available. The only thing between the choice of using stuff I already have or buying car sound system components is the power required... Which would mean there is a circuit inside the car amplifier boosting the battery voltage... Can anyone suggest a simple circuit or easily available gadget to boost the 12 V car battery voltage to the required +- 9 up to +- 40 V required for the variation of designs available. I am thinking of using (X2) the 200 W Velleman kit (+- 30 V) or the TDA 7294 chip (+- 40 V) for my bike amp, but would also like to know how to boost to arbitrary values (like, 17, or +- 21V) (for understanding). Of course, not just voltage, but also power is needed here!

Question by BobS 8 years ago  |  last reply 8 years ago

I am looking for instructions or tutorials that would be helpful in building a DC boost converter to convert 9.6V to 12V

I am looking for any kind of information that would assist me in building a DC boost converter.  I understand how a DC boost converter works but don't know the math behind it so I am unclear about the types of capacitors, transistors, inductors etc I would need.  Any help in how to calculate these values or how to build this circuit would be great!  Thank you.

Question by mezi24 8 years ago  |  last reply 8 years ago

How do I build a DC-DC boost converter?

Hey Guys! I want some advice regarding boost converters. I want to charge a capacitor rated for 450v 1150uF using a boost converter with input voltage >12 volts. What kind of inductor values will I need? What should be the duty cycle and frequency of the square wave generator? And is there any formula to calculate this or a calculator? Thanks in advance, IndianHacker002

Question by IndianHacker002 3 years ago  |  last reply 3 years ago

DC to DC Convertor?

Does anybody have a circuit that is able to turn solar power from a solar panel (preferably 1 watt) to make enough juice to recharge an iPad? The iPad requires 10 watts of power to charge. I wanted too use Adafruit's mintyboost but I don't think that has enough power to charge the iPad. Any suggestions?

Question by blinkyblinky 7 years ago  |  last reply 7 years ago

DC to DC converter

Hi ppl, for electronics A level coursework i am hoping to build a DC to Dc converter to use to power high power leds. As far as i understand it will convert DC to AC, use PWM to alter the current out, and then convert this back to DC giving a constant current out. These are available in devices (known as buckpucks) but for my coursework i hope to build a similar thing on Breadboard. This is really a question for the engineers and if they could give me some advice on anything to do with this it would be great! Thanks ppl

Topic by drummer ian 11 years ago  |  last reply 8 years ago

dc-dc Buck vs boost efficiency

Hi guys. When you  use solar panels and have gadgets with different voltage requirements  that you want to power up. I need atleast  2 different outputs, 5v and 12v  ,   so which is most efficient ,  12/15v panels that you  regulate to 5v , or  5v panels boosted  to 12v? is there any general advantage in either case and i,m talking about using  cheap ebay switch regulators / boost converters,  not anything expensive hi tech. regards

Topic by kristerh 5 years ago  |  last reply 5 years ago

Boost Converter?

I make the rwilsford07 boost converter, but it doesnt work. The mosfet start heating and only gives 2v. I check the oscilator and is working perfectly, I try diferent things butit doesnt work. Before I make 120v, but I dont know how it stop working, I nad rebuild the circuit like three times but nothing happens. Can you help know why is this happen?

Question by Kurt Gerhard 7 years ago  |  last reply 7 years ago

volatage booster

Hi every one . i need to know if its possible to boost DC voltage from 0.1V source to 3.8V DC output and how to do it  thx for answer :)

Topic by insurgent 3 years ago  |  last reply 3 years ago

Boost Converter help

I need a dc-dc boost converter that will step 25.9 volts at 2600 mah up to around 388v at 360 ma will I need a battery back with a greater amp output I can get up to 12000 mah at the same voltage any suggestions I am trying to charge a .1 farad cap bank that consists of only 10 caps Any help is appreciated -TDC

Topic by ThinkDesignConstruct 4 years ago  |  last reply 4 years ago

Best Way of Boosting 7.4VDC to 12VDC? Answered

I need to power two stepper motors off of 7.4VDC, and am trying to figure out the best, most cost efficient way.  What type of DC booster circuit would be best for this application? Do I need any noise filter? If yes, what kind? If I understand correctly, Stepper motors need a constant current. Does this limit my selection of DC boosters/step up devices?

Question by RocketPenguin 2 years ago  |  last reply 2 years ago

DC to DC UPS (Help!)

Hi i am trying to build a sort of DC TO DC ups for my modem/router, please look at the image attached for my project plan. I was able to find many charging circuits online but i cant understand what value relay and capacitor should be used. can any one help me with this project. Thanks in advance.

Topic by spooge 7 years ago  |  last reply 7 years ago

Why does this boost converter circuit not work?

I tried this circuit using a 3.7v supply and instead of a 12v Zener I used a 5v Zener. I also used a 22uH inductor. I get 5v no load but when I add a load the voltage drops a bit and the current is 50ma max. Why is this not working and what could I change to make it work? If this is the wrong circuit altogether, then what discrete circuit would work?

Question by Davis Lambert 3 years ago  |  last reply 3 years ago

DC to AC Converter Circuit

Hi, so I have a sound amplifier that is designed to run off of 18-28V AC power, but I want to try and run it off a 24V Battery, can anyone give me a circuit that would achieve this?

Topic by Fozzibehr 5 years ago  |  last reply 5 years ago

Minty boost DC-AC Switch

So I have this idea to put an Ipod into an old CD player case to make the ultimate Ipod Pod. I want to use the Minty boost for battery charging, but I would also like to use a DPDT switch to switch between the DC power of the batteries to AC power of 4.5 volts. I tried to research this and came up with a plan, but I'm not sure if this would work.

Topic by fresh1 9 years ago  |  last reply 9 years ago

Arduino DC-DC converter? Answered

I have an Arduino project which drives a set of 12V LEDs using NPN transistors, I had been using the linear regulator on the Arduino to convert 12V to 5V for the Arduino and Ethernet shield, however I have some IL1205 DC-DC converters which could also be used, personally I think the IL1205s are the better option as they seem to dissipate less heat then the regulator on the board. Are there any other solutions to this, It would be ideal of I could power the entire project from a single 12V power supply, it also has to run continuously so must either produce little heat or be easy to dissipate the heat away from. Also because of the circuit I have to bridge the -Vin and -Vout terminals of the converter (for the transistors to work properly) I assume there is no problem in doing so. Any help is greatly appreciated. Thanks, Dan

Question by DanNixon 6 years ago  |  last reply 6 years ago

DC power + or -? Answered

I have looked at lots of Instructables and websites, but there is a 50/50 split that power flows positive to negative and negative to positive. Which is it? I use both, depending on the circuit I am building it is easier to build one way over the other (NPN and PNP Transistors usually) But I have heard that it used to be thought that positive flowed to negative but I have since heard that the new idea is that it flows negative to positive. I know that everything is supposed to flow from higher concentration (+) to lower (-) but we could have batteries labeled wrong so I don't know. Very confused.

Question by Electric Spectre1 9 years ago  |  last reply 9 years ago

I need a diy solution to boost 6V DC to 12V DC @850 mA

I have torroids from pc power supply units, loads of transistors, 555s, uControllers, diodes, caps... all sorts of stuff.

Question by yaly 4 years ago  |  last reply 4 years ago

Is the circuit ok? also please explain "What the circuit is doing"?

The circuit shown is supposed to produce AC where v1 is a 9v battery, c1,c2,c3,c4 are capacitors and t1 is  a transistor (BD140), R1 is a resistance AC squarewave of 140-150 kHz is required .........sorry for poor image quality please use "magnifier " if needed.....Thanx in advnce!

Question by jatinbatra 6 years ago  |  last reply 6 years ago

Mobile phone wind generator

Hi at school, I am making a mobile phone generator. It's only GCSE so my apologies for my lack of knowledge. It is meant to be a "wind generator" but it can basically be a renewable generator via motion. So since I get to take it home afterwards I designed it to be a little record player where you turned the platter and it would change a phone. This is where I need some help. Would this 24v motor provide enough juice to charge a lithium ion battery (with a boost or buck converter [if needed to step down to an appropriate voltage] then a constant current protection circuit etc) the output 5v to charge your phone? Here is the motor:|pcrid|88056614883|pkw||pmt||prd|2483716&gclid;=CjwKEAiA4dPCBRCM4dqhlv2R1R8SJABom9pHi1B_sRuR-4nr15ce-EWd51aCsEfYqFBsUJioUXEpvRoC1unw_wcB Thanks! For non-British readers :  a GCSE is (in the UK except Scotland) a qualification in a specific subject typically taken by school students aged 14–16, at a level below A level.

Topic by MukymooD 2 years ago  |  last reply 2 years ago

Help With This Inductor Anybody?

Hey. I'm still learning a lot about electronics, and I'm still very new to that kind of thing, but am trying an electronics project for the Green contest anyway. I did some research on how step-up converters work and finally have settled on a circuit that would work for my project. My problem lies with one of the parts. I needed a 68uH inductor. When I ordered it, the picture below was what I got. This didn't seem quite right. It may be the correct thing, I don't know. So what I'm asking is... A. Is this the part I'm looking for? and B. How would I attach this to the PCB I'm etching for the project. Thanks in advance. My pic was a bit blurry so I found something that looked similar from the internet to go along with it.

Topic by Gjdj3 11 years ago  |  last reply 11 years ago

DC time delay? Answered

Here's the situation-I close a switch completing a circuit,providing DC power to a load(6 volt,0.1 A).But I do not need the load to start functioning as soon as the switch is closed i.e,only after a delay of say..30 seconds.I googled for "Time delay circuits" but the ones I got were either dealing with AC or the transistor -capacitor(Time Constant) based circuits that makes a load function for a preset time after the circuit switch is opened.I think I could achieve this "pre-delay"  with elements such as transistors,resistors,capacitors etc. but I can't figure out how.Please suggest possible circuits that can be used to achieve my purpose.

Question by Adarsh_tronix 6 years ago  |  last reply 5 years ago

Can anyone help me with an schematic for dc-dc boost converter,from 3.5-3,7V to 5V to charge a phone? Answered

Hello everyone !! I need a schematic for boost converter but with basics components,i need to find them in my country and not very much to cost. I need it for charge my phone from another cell battery with 3,7V. Like an portable charger. Please help !!

Question by danyelo 5 years ago  |  last reply 5 years ago

convert 12v to 14.5 v simple? Answered

Hello. i have an LCD monitor powered from AC, that i want to make to be powered by DC for use in my car. the monitor PSU , supplies the controller with +5v and +14.5v. and i want to power the monitor from a regulated 12v psu. my question is, how would i make a dc booster, from 12v to 14.5 v at 2 ampere? thanks in advance!!

Question by settra 5 years ago  |  last reply 5 years ago

Minty Boost Help

So, I plugged in the USB to an iPod Mini and the whole cicuit goes blank. I tried it on some person's MINI, but the light shut off right when I switched the switch. HOWEVER, it did work on my iPod Nano and my sister's iPod Mini. It seems like the circuit is shorting out on the MINI and not on the Ipod Nano. I am thinking it is a problem with the noob sauce's MINI, but I do not know why it is shorting out and turning the light out on the charger. Thanks -Brennn10

Topic by Brennn10 12 years ago  |  last reply 12 years ago

Best DC Motor Starter Circuit I ever Saw

I wish I had drawn this very good DC Motor Starter control. There are enough questions about a starter box, this is one. It has everything you need to wind up a big machine. A

Topic by iceng 6 years ago

can i power my minty boost with these D cell batteries ?

Will i get more charging hours by using them?what is the maximum number of D cell batteries i can use in series to power a minty boost circuit?or how much input voltage can i give to a minty boost circuit?

Question by imakethings 8 years ago  |  last reply 8 years ago

how can i boost the current from 2A to 6A while keeping the 19V from my dc-dc converter?

I have made a dc-dc converter to run my laptop of a 12V (car) battery using a lm2588 switching regulator. But my circuit isn't powerful enough. I can get a maximum of 2A out of the converter. Is there a way to boost the current to a maximum 6A?

Question by ForwardUntoDawn 6 years ago  |  last reply 6 years ago

Pololu NCP1402 Boost Regulator??? Answered

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 7 years ago  |  last reply 7 years ago

How does the joule thief circuit work? Answered

The best i can figure, the current coming through toroid turns on the transistor, then the collector drains the current to the negative, while pulling it from the emiter back through the diode to the collector? if i am correct, how would this boost the voltage?

Question by revelae 9 years ago  |  last reply 8 months ago

Inductor Heating Problem Answered

I'm having a bit of trouble with an inductor implemented as part of a boost converter. The circuit works fine except for the inductor gets very hot within a few seconds after turning on. There are also noticeable high pitched noises coming from it associated with varying current loads. I'm not really sure what the issues are as the circuit is within the maximum DC current rating (circuit draws around 120mA, inductor is rated for 250mA) and resonant frequency is also quite low (around 1.5kHz). Datasheet for the inductor I used can be found here. Some help would be appreciated in determining what the problem is and in locating a suitable replacement inductor. Thanks.

Question by andy70707 3 years ago  |  last reply 3 years ago

Help with DC motor control circuit

I am looking for some advice in regards to a DC motor control circuit i am trying to build out of some electronic parts I have lying around. See attached control circuit diagram.  The idea is that a timer will trigger the relay to either run the motor in reverse at full voltage or it will run forward stopping and starting as per the wave form from the 555 timer. So on for about 2 seconds and off for about 2 seconds. This waveform can be changed using R1 and R2 which are trim pots.  The circuit works as expected until I hook the motor up. When the motor is meant to be following the waveform from the 555 it will actually stop and start very erratically. Any help on the reason for this would be great.  Also this is one of my first electronics projects and any feedback on my design would be appreciated. 

Topic by jmullo 2 years ago

need help with AC to DC circuit

Hi all, im a newbie in engineering but had to do a project on a 2.1 speaker. i need to design a circuit for changing a 240Vac to 14.2Vdc, but after weeks of staring at websites, i still have no idea how to start on it.i found a circuit online, but i had to modify it to let the output be what it is needed. output -> Power: 50W; Voltage: 14.2V; Current: 3.5amp this is the link for the circuit i want to modify.can someone help me please ><

Topic by ada 12 years ago  |  last reply 12 years ago

Where to put fuses in a dc circuit? Answered

Say I have a 12 volt battery and I want to connect a light and a radio.  Should I put a fuse next to the positive or negative terminal of the battery?  Or should I fuses in front of everything.  DC current flows from pos to neg right?  so I would put the appropriate fuse on the positive side of each electronic device?     Thanks

Question by Noblenutria 8 years ago  |  last reply 1 year ago

Help wth a 12v DC circuit

Hello all2 Questions pleaseI am working on a hobby project and I am needing to hook a 12v computer fan (200mm) which is 0.3A max...up to a Turnigy 5.0 Li-Po battery. The battery is 7.4v, 30-40c discharge, 5000mAh. I have ordered a DC to DC adjustable voltage "step-up" converter to increase the output to 12v (I am hoping this works). (Q1) - how (if at all) do I limit the output amperage to 0.3A without burning up the fan motor.The fan is going into a cosplay set of foam armor (to help keep some air flow going to try to keep semi-cool) and I am hoping to be able to run the fan for about 3hrs. If I can accomplish the above, (Q2) - how long might the fan run?Attached is the "step-up" I ordered...

Question by Jeepguy001 4 months ago  |  last reply 4 months ago

DC Motor Stop and reverse for a feeder

Hi, I attempting to design a feeder that will raise and lower an access door to where the feed is at. The door will open at dawn and close at dusk. I am trying to design a setup similar to an automatic car antenna. When enough light hits the photocell, the motor engages, travels a distance or hits resistance and stops. When light is no longer strong enough, the motor engages in the opposite direction and after the same distance or it meets resistance, stops again. Is this possible to do without Arduino as I am trying to keep this cheap? If so, what do I need and how can this be accomplished? The photocell is not a requirement as I have seen astro timers that can adjust for the changing sunset and sunrise times. Please help. I've got at least 20 hours of research into this and am hitting dead ends searching forums. A circuit drawing would be an awesome addition!!!!!!!!!!!!!!!! Thanks in advance

Topic by tincupchalice 2 years ago  |  last reply 2 years ago

LM35 circuit design

Hi, any advice on putting an LM35 into a circuit to control a small (120w max) DC immersion heater element so that it maintains water temperature around 38C ? Thanks

Topic by RionZion 1 year ago  |  last reply 1 year ago

I make the rwilsford07 DC-DC HV Boost Converter and it only gives 32 volts

I want to build the DC-DC HV Boost Converter but it only gives 32 volts from a 9volt input. The output voltage depends on the number of oscillations? I am using coilcraft PCV2-394-05L and the mosfet 75N75

Question by Kurt Gerhard 7 years ago  |  last reply 7 years ago

sony dcs-w50?

Not only is my lcd screen cracked but my flash doesn't work, saw how to fix screen need instruction to fix flash in my camera,?????  HELP

Question by woody55 8 years ago  |  last reply 8 years ago

i need to boost 12v dc to 18v dc can i do that?

I have a sensor that I would like to run in a engine Im building but its a 12volt system and the sensor runs on 18volts. How or can I do this? Oh thats dc volts

Question by Joekirs 7 years ago  |  last reply 7 years ago


RELATED TO DC MOTOR CONTROLLER (EV VEHICLES) 1: Need for large number of capacitors in the power circuit (store the charge and dissipate to which part of the component mosfet or diodes ??) ? 2: what are diodes parallel to the mosfets for ? ( other than preventing the back emf coming from the motor ) and is it have anything to do with firing angle ? 3:advantage of using many mosfets in parallel than using a single mosfet and on what basis must that mosfet chosen? I am from India a college student pursuing my electronics engineering and making motor controller,i am able to get all the circuit details and how the motor controller works but i have above few doubts

Topic by doraditya 5 years ago  |  last reply 5 years ago

How can I convert 9 volts DC to 1 millivolt DC?

I need to be able to convert 9 volts to 1 millivolt. Is there a schematic/circuit that can do this? If so, could you please provide one or details on how to make one? Thank you!!!

Question by vak52 3 years ago  |  last reply 3 years ago

high capacity joule thief/dc-dc converter

I'm trying to make a dc-dc converter with the following characteristics: Output = 5V regulated at up to 30mA = 150mW Input 1V (or lower) from a slightly flat AAA. Assuming a pessimistic circuit efficiency of 50%, then the input current would need to be 150mW / 0.5 / 1v =  300mA which I think a AAA is capable of supplying. I'm using a variation of "led torch circuit 2" from, but I've replaced with the 1n4148 with a schottky diode and replaced the 2 LEDs and 29R resistor with a 5k6 and 1k resistor respectively; this should limit the output of the circuit to just under 5v. I have a 150R resistor to provide a 30mA load to the circuit. When the input is 2.4V, the output is 4.62V which is close enough to 5v for me.  But if I decrease the input voltage to 1.14V, then the output voltage falls to 2.7V which is not enough. I have tried half a dozen hand wound transformers with various turns ratios, wire thicknesses and shapes (slug and toroid) but am unable to achieve 5v out (at 30mA) from 1v in. Does anyone have any suggestions as to what to adjust, or perhaps a better circuit?

Topic by GrotBox 6 years ago  |  last reply 6 years ago

Where can I find a circuit converting AC power of a bike dynamo (generator) to DC power?

Where can I find a circuit converting AC power of a bike dynamo (generator) which generates from 0 to 30 volts and convert it to DC power ? The circuit should be as efficient it can be. The dc conversion will be at 5 volts. Can you help me ?

Question by panigrc 8 years ago  |  last reply 8 years ago

Can someone explain what all these connections on this transformer are for? Answered

I pulled this transformer out of a complex circuit I found in the electronics recycling box. It says it's a "TurboLink Switching Power Supply" but I have no idea what that is either. Perhaps someone could explain that too? Anyways, I want to see if I can possibly use this transformer in a DC circuit to increase the voltage, but it would help if someone could explain which wires are connected to the primary and secondary windings! Also it would be nice if someone told me if it's even possible to increase the voltage in a dc circuit. For example, is there a way I can connect this transformer to a battery so that it converts 1.5v to something higher? If you look at the picture, I think the 6 connections poking out just under the yellow part are all connected to the two wires coming out at the top beside my index finger. Then there are two leads and the bottom. Anybody know what they do? I connected one end of a 1.5v battery to one of the leads at the bottom and when I rub the other end of the battery on the other lead it produces small sparks.

Question by Ke-Bob 8 years ago  |  last reply 8 years ago