5v volt regulator circuit which can be made from only three components, its simple, cheap and easy way to get a current up to 1A and a voltage of more than 5v can only be regulated by this circuit, this circuit can be used as a bread board power supply

Step 1: components

1.............. L7805

heat sink ( a small aluminium plate from scrap)

1...............10uf 25v (electrolytic capacitor)

1................1uf 25v(electrolytic capacitor)

green LED (optional)

1k resistor(brown black red) (optional)

soldering iron


common circuit board
<p>how can you tweak this cicruit in order to produce lesser current. I need 5v and 400 ma output. Should I get another capacitor with different capcitance, if so what?</p>
<p>hi!</p><p>can you tell me which regulator i have to use if i have to drop from 19v to 16v 3.5A</p>
<p>I can only find 50V 1uF capacitors online</p>
<p>If you're still curious, 50V is the MAXIMUM that the capacitor can handle, it can run at much lower voltages ie. it'll work perfectly fine for this purpose. Try this website for your various electronic needs, it's already linked to capacitors (no I'm not sponsoring/promoting them, just saying it's a good place for parts).</p><p><a href="http://www.parts-express.com/cat/electrolytic-capacitors/1378" rel="nofollow">http://www.parts-express.com/cat/electrolytic-capa...</a> </p>
<p>You are amazing! I thought nobody would get back to me. Thank you very much for the help, people like me just get lost on the most simple of electronics ;)</p>
<p>i have create a power supply for mobile charging using 12 volt transformer 1A c and 7805 regulator . the circuit is ok . but i apply the load to the circuit the voltage are reduce from 5 volts to 3 volts and mobile phone is not charge ....... any one help me </p>
<p>what is the output current of the circuit?</p>
<p>What wud happen if i supply 24 V ????</p>
<p>it will work</p>
If i connect so , on giving 5volt will the output will be 5v or will there be a drop
<p>There will be a voltage drop. Usually, you need to supply 7vdc minimum to get reliable 5vdc out. Look up the datasheet of your particular regulator for specs.</p>
<p>Thanks for the instruction, this helped me a lot</p>
<p>Hi, there is a little mistake on the first image. </p><p>It says L7805 transistor and should be L7805 Voltage Regulator.</p><p>Grettings!</p>
<p>Hello nice project, but I have one question</p><p>What happens when the original battery voltage drops below five volts? will it still output that lower voltage or nothing at all?</p>
<p>The voltage regulator doesn't work if the input is less than 6V (this value varies with the manufacturer) and can hold upto a maximum of 35V. But coming to your question, what will be the output if it is less 5V? </p><p>The voltage regulator, basically dissipates energy to achieve its function. And since the input is less than what is recommended, some energy is lost in its circuitry and the output is much less than the input. eg. if I give 5V to the input, some energy is lost inside and the output would be around 1.7-2V . </p>
<p>hi what if i have a 24v and i want to convert it to 5v </p>
<p>I plan to make something like this to power a Raspberry Pi B+ in my car. What regulator would I need to supply 5v 2amp output. Sadly the L7805 just doesn't have the amps I need.</p>
<p>Thank you for this circuit, just what I was looking for to charge lithium batteries, regards Doc Cox</p>
<p>Can i use it with a 12V-5A to step down for 5v-1A DC , 5A to 1A ? the power supply current can be affect or not ? i think i do affect , doesn''t it ? because i''ve alreay had a 12V-5A DC and want a 5V-1A for my device !</p>
<p>the output from the circuit is 5v 1A. if you give 12-5A as input the heat sink size used for the 7805 IC should be increased as it gets more hot.</p>
<p>Just let a volregulator drive a fet or and use a zener and a shunt resistor or better, just read the millions of articles about the most used voltage regular serie in the word, from 1976. But don't expect high end superstable low noise, low quiscent currents(warmth). This is the most standard 'schematic' possible and a filmcapacitor couldn't hurt neither then a cheap elco and you can never drive a voltage regulator like this one, with a lower input voltage then the output .They are not efficient and need power to maintain the output voltage and current. And switching 12 v 5a are more efficient parts for on the market, redcon makes good ones, but i think you mean that your powersupply is able to give max 5A , why would you else want 1A. analogue devices has a lot of articles (and very nice components) on their website.and the max amperes a 7805 can draw, i've seen was 2,5A , but the most 1 to 1,5 A With a coolblock. If you want more power and be able to adjust the adjust the output voltage take this one http://www.ti.com/lit/ds/symlink/lm350-n.pdf. with a lotttt of schematics, included formula.... goodluck</p>
<p>can i use this regulator to regulate 3v to 5v</p>
Hi NiranjanS1. The regulator does not 'stepup' voltage. It's only used to regulate voltage downwards.
<p>And what maximum input voltage L7805 can handle?</p>
<p>Hi, thanks for sharing, Can I use an input of 24v and still in the output stay in 5v, if No what should I do, change the transistor or the capacitor values ?</p>
<p>HI, If you look at the link below you'll see a great write-up about this particular regulator. But for the short answer it will work but it'll throw out more heat. The closer the source voltage to the output the less heat there will be. Make sure you have adaquate cooling! </p><p>http://www.learningaboutelectronics.com/Articles/What-is-a-LM7805-voltage-regulator</p>
<p>Hey ! to all instructablers out there<br><br>I was just wondering if it is ok to use two 70 microfarad capacitors .<br><br>Thanks, your replies are appreciated<br><br></p>
<p>long story yes with an if...</p><p>short story no with a but!</p><p>the circuit is designed with a large and tiny capacitor. you could have a 900 microfarad capacitor before but you must have a less then 2 MF capacitor after </p>
<p>Must have &lt;2uf after... Thanks for the info, but a reason or reference would be much appreciated... surely larger is better? Or does a larger cap take longer to charge causing hysteresis?</p>
<p>Thanks. </p>
<p>Do you know of a way to stabilize at 5 volts output but having an input at 5 volts? When I put a load on, the voltage drops to 2 volts output.</p>
<p>the 7805 is a voltage regulator it will &quot;stabilise&quot; an input voltage of 7-35DCv to a regulated 5DCv what happens after is your problem.... </p><p>if your not meeting said requirements it will not work correctly.</p><p>heat, amperage and capacitance will also be a factor i like using a larger capacitor at the lead-in and smaller ceramic capacitors with the other circuit components.</p>
<p>According to the datasheet for my 7805 regulator the recommended minimum input voltage is 7V. At an input of 5V the device is under-powered and not working efficiently so you're getting low voltages at the load. In other words, to stabilize the output at 5V you'll need to increase the input voltage. Also, if your input is a guaranteed 5V, perhaps you do not need even need a regulator. https://www.sparkfun.com/datasheets/Components/LM7805.pdf</p>
<p>Hi! </p><p>What happens to the output when the input voltage is 5v?</p>
<p>I made mine with the 0.1uf ceramic capacitor like you stated in one of the comments</p>
<p>I created a picture of how I'm wiring a LED and a resistor (see attached), but when I measure the voltage between points A and B, I see less than 5V. I suspect some current escapes through the 1uF capacitor. Could someone have a quick look if I should put the led+resistor on the orange line instead? Would that be the proper way to use capacitor for stabilization? Also, am I connecting the 10uF capacitor correctly, or it should be rather in series on the plus line or ground of the battery?</p>
<p>You are probably measuring around 2-3V right? This is because you are measuring the voltage across the LED, not the entire output. If you measured from Point A to the other side of the resistor (the end going to ground, or the negative side of the battery), you would then measure closer to 5V. The voltage regulator is outputting 5V. Some of it gets &quot;used up&quot; by the resistor, and some by the LED. Measure across the LED, then measure across the resistor. The two readings should add up to 5V, which should also be the same amount measured across the LED AND Resistor together.</p>
<p>Is there an alternative to the 1uF 25v capacitor? I am finding it extremely hard to find in the UK and don't wish to buy from China as the delivery will take too long. Would something like a 1uF 35v work? or something lower?</p>
<p>1uf 35V would work. The voltage ratings on capacitors indicate the maximum voltage that the capacitor can handle and thus a 35V capacitor instead of a 25V capacitor would work. Technically, a capacitor rated as low as 5V or 10V would still work. Also, the datasheet actually recommends using a 0.1uf (100nf) ceramic capacitor on the output and not a 1uf electrolytic capacitor.</p>
<p>I want to make a 5V charger for my old 6V Motorcycle (iPod, iPad, iPhone). My question is, Will the circuit work with a 6V input, and even though it is a DC to DC application, would a capacitor be useful in case there are spikes coming from the old voltage regulator?</p>
<p>Using a 6V power source for the LM7805 regulator will not work. LM7805's have a dropout voltage of 2V meaning that the input voltage must be at least 2V above it's output (5V + 2V = 7V Min). Attempting to use any voltage lower than 7V will yield a lower, unstable voltage (typically 2.0V - 4.5V).</p><p>As a side note, for all linear regulators, a higher difference between the input and output voltages will create more heat which can exceed 150 C.</p>
cant u just use a 7805 regulator?
yes the caps are for ac dc to dc just regulator is fine i hook up 2 100k ohm to my circuit to charge my iphone 4s off a dollar store 9v (will soon add a joule theft circuit)
Hey I got 3 of the L7805 and 2 are + and one is - will the - still work?

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