Will LM7805 exceed its specs? || electronics experiment

In this experiment I'm pushing an LM7805 linear voltage regulator to its limits. According to the datasheet it is rated for maximum 1.5A loads. I'm trying to check if the regulator can exceed its specs and deliver 2A or maybe even more.
I'm using power resistors to simulate a relatively constant load.
WARNING
This is just an experiment. Never exceed voltage and current values provided in the datasheet. This may damage your component, shorten its life span or even cause fire.
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Video, edit, voice by Chris Lorkowski

[@alfblack2]

loving this series.

[@houseofelectronics5869]

Very nice. I'm eager for more videos like this :)

[@ElectronFunCom]

That's the kind of answer I was looking for! Thank you for your comment :)

[@MuhammadFaridulIslam]

Do not seek good comments. Just release the good video (like this one) regularly. Visitors will comment willingly.

[@whollymindless]

No I won't.

[@moon1985bc]

great experiment!

[@TheAussiePirate]

More vids please, these are great!

[@ElectronFunCom]

+Carl Alm Thank you so much Carl :) I'm trying to organize everything to make more videos. However, it's not easy with a regular job.

[@HariWiguna]

Oh... good ol' 7805 :-) With prevalence of USB phone chargers, and power banks, I have not used a voltage regulators for a while. It might be interesting for future video to compare the LM7805 Linear Voltage Regulator and the AMS1117-5.0 Low Drop Output regulator.

[@ElectronFunCom]

Thanks for the comment and the nice idea for a video Hari. I hope to test some low dropout regulators one day.

[@shrinivasmohod]

I have made 5 volts circuit by using L7805CT TO-3 Package, by 12v input and rectified with bride diode and filter with 470uF 50V cap. But the output is showing 15.56 volts at last points. Why is this happening?

[@DannyBokma]

You might have gotten a better reading if you actually measured the regulator output instead of the output after the current measurement ( the DMM will create a significant drop since its a resistance based current measurement). At 2 amps the wire clamps you used might also introduce quite a voltage drop. Neverthe less, nice video!

[@ElectronFunCom]

That's true, the wires themselves introduce a bit of voltage drop too. This video is just a proof of concept. Thank you for your feedback :)

[@marsrocket]

I'd be interested to see you test more samples. It may be that some 7805s perform better than others. Different batches or different manufacturers maybe.

[@ElectronFunCom]

That's a good idea and I've been thinking about it too. I tried a couple of these regulators, but all were from ST and from one batch. I might do a little test and post it as an update - a whole new video with testing different copies would be a bit too boring, I guess.

[@osamahnajjar2824]

Thank you , i was thinking about it long time ago but never tried it

[@ElectronFunCom]

I'm glad you liked this video :) Thank your for the comment!

[@technicmasters7936]

Did you reasembled the gpu after the test? (If the gpu is fully working)

[@leroyjones6958]

Let's see you do same thing with 78T05CT 3 amp version, then 78S05CV 2 amp version and then finally how about an LM323 in the TO3 case which is a 3 amp version. With a really large heatsink, I wonder how far those 2 and 3 amp versions could be pushed?

[@SLLabsKamilion]

So, I'm kind of curious why you did not have a thermocouple hooked to a multimeter to show us the temperature of the regulator... Lacking one in your toolbox, perhaps?

[@ElectronFunCom]

I have the thermocouple and should have shown you guys the temperature - the highest reading I've seen there was approximately 50 degrees C/122 degrees F.

[@bipinv211]

I want to charge an 8v,4600mah battery when I use 7808 it’s burned out within 2 mins can anyone suggest a solution pls

[@ABaumstumpf]

With that setup i'm rather certain it is not yet the LM7805 that is limiting you. Just look at those tiny wires you are using for the current and then the probes attached.... Those wires can easily add 1 Ohm.

[@ElectronFunCom]

That's true, the wires will usually add some resistance to your circuit. The wires I used don't look too thick, but they are from a PC power supply and are good for delivering quite serious amperage (don't remember the exact values right now) - the probe is probably the worst part of my circuit.

[@abeditani8293]

LM317 consider a 1.5A max but I successfully get to give me 2.5A but in 5W of a 2V drop across the LM input/output . So I think I can install your 5v linear regulator with input 7v and output 5v and you can try get more test output current . This regulator cannot handle a more than 8W internal heat they get shut down . Even in 6W they need a cooler fan . I think you can use a linear regulator after a buck converter with a minimum deferent voltage between the input and output like 2 to 2.5V drop inside the LM regulator with max 2 to 2.5A current . And that can surely give me a nice 5V output for a 2.5A max as a USB power supply charging a 2 smartphone and powerbank in same time with out any problem or nose from output voltage that can get from the buck converter that it was make the smartphone act crazy in the touch act alone .

[@uK8cvPAq]

The safe operating area of the device is what governs the maximum output current.

[@ElectronFunCom]

It seems the LM7805 is idiot proof :)

[@uK8cvPAq]

Pretty much, I've done really stupid things like connect one to a car battery and accidentally short the output and it survived so they are quite robust. But if you connect it in reverse or allow the input to go lower than the output they can be quite fragile, a diode from output to input solves that.

[@ElectronFunCom]

The thermal and overcurrent protection features help a lot, but still I've fried quite a few LM7805s. As you said - there are certain situations, in which these regulators may fail quite easily.

[@porkimond]

haha its a bit nuts, i wonder how much heat was dissipated by the gpu heatsink :D

[@ElectronFunCom]

It was supposed to be an extreme experiment :)

[@jp-um2fr]

I have noticed that generally speaking fans seem to be taboo in linear power supplies. The argument is that they are noisy and unreliable. Anyone reading this with a PC next to them is hearing a fan. Fan assistance can more than double the efficiency of a heat sink. The number of power supplies on KZbin being repaired due to heat is rather high. Yup - I'm a fan fan. Thank you for this video and the buck converter one. More - gimme more.

[@ElectronFunCom]

Fans are commonly used for example in linear lab power supplies and it's true they may be noisy. I'm not a fan of my Korad power supply when its output is set to 3A or more :) However fans are very useful and indeed they multiply the efficiency of a heat sink. I'm a fan fan too - my first KZbin video is about cleaning a computer fan :D Make my boss fire me and I will upload more videos and much more frequently ;)

[@jp-um2fr]

I belong to 3 electronics forums and mention a fan and they go all bananas. I should have written DIY power supplies. There is a chap on KZbin FFcossag. Mention a fan and he goes into hysterics, then promptly mends a power supply that's got overheated. I have a 40V AC 50A transformer. That would make quite a linear power supply with the odd 2N3055 or whatever stretching into the sunset fans blasting.

[@ElectronFunCom]

Like you said before - a fan can double the efficiency of a heat sink. Passive cooling is sometimes just not enough.

[@jp-um2fr]

I phoned the firm below and they were very helpful. Most PC fans are pretty gutless (0.3A) and I can't find anything better. They'll do for now. www.abl-heatsinks.co.uk/index.php?page=extrudedproduct&product=166

[@ElectronFunCom]

Which fan size are we talking about? What would you like to use it for?

[@KuntalGhosh]

i found a ups for free with a bad battery . just before buying a new battery i hought lets give this 14.4v with 10amp because a battery cost 15$ and as soon as i powered on it showd 172volts 250hz on the out put so i put a 22w fan and the voltage rise to 190v and 2 amps were drawn then i put 2mobile charger and it rise to220 then i plugin in my pc and monitor and it quickly got to250v and 4 amps were drawn.. i got worried about the voltage and started lowering the input voltage but the out put voltage keep riseing so i got it to16v and it gone down to 220v then i switch on my pc and my psu cant give 12amps so i stop the test .. now i want to know what wrong with it .. it is a very cheap ups . i have no ups on my pc and should i get a new 1000va apc ups or repair this junkyard ups or search for another junkyard ups??and with higher load the frequency also got at 54hz

[@ElectronFunCom]

I won't be able to tell you what's wrong with your UPS, sorry. However, I wouldn't use it to avoid unnecessary risk.

[@KuntalGhosh]

ElectronFun.com yes it is better to find another junkyard ups that works properly wait and save some more money to buy a new apc ups..i am building a new pc and buying parts one by one because i am a poor kid. i have bought a ryzen 7 1700 for 372$ as it is the cheapest available in india.. i have no mney fpr motherboard ram and gpu lol

[@ElectronFunCom]

That's too bad. Why wouldn't you wait until you collect all the money needed for all the parts?

[@Miata822]

Interesting stuff. Disappointed you quit making videos. It takes a while to build up a following on KZbin.