Greetings,
I am new to electronics but interested in learning, I searched and learnt on various blogs on Google that 7805 can reduce a12V input supply to 5V. Looks like 7805 is heating up a lot.
I have added a 1000uf capacitor in parallel with input and a 100uf capacitor in parallel with output. I learnt this also in a YouTube video.
Are there any other alternatives to 7805 that heats less? PS, since I am a novice, it should be easy for me to solder/setup.
That is why heat sinks are made and used! Do you know how to compute watts? Volts time amps. Your 7805 MUST dissipate 12 volts minus 5 volts = 7 volts times the current passing through the 7805. All that heat must go somewhere else the 7805 will continue to get hotter!
PS If you reduce the input voltage on the 7805 to, say, 8V, it'll heat up a lot less. A heat sink is still a Very Good Idea.
The heat generated in a linear regulator depends on the voltage dropped across it and the current through it.
The wattage (which is converted to heat) is calculated as Voltage X Current. For example, 12V dropped to 5v and 1 Amp, the regulator is dissipating 7 Watts, with the 5V load using 5W.
The LM7805 is rated up to 1.5 Amps, but that requires a BIG heatsink and it may depend on how much voltage is dropped across it so at a higher input voltage you might never get 1.5A, even with a big heatsink.
If it overheats it will shut-down or oscillate. (It's thermally protected and it should shut-down before it burns-up and dies.)
A switch-mode (or "switching") voltage regulator can be almost 100% efficient, which means it doesn't get nearly as hot, and you can actually get more current-out (at lower voltage) than you feed-in.
Switch-mode regulators can be tricky to build so it's usually best if you buy a pre-made module/circuit board.
Yes, use a switching step down regulator. They are much more efficient, except when the voltage drop is very low (like producing regulated 3.3V from a 3.7V LiPO battery).
You can get a switch mode regulator for about a buck at some china vendors. It will plug in where your 7805 goes and has the necessary capacitors etc. It will also run much cooler and not need a heat sink. Much less $$$ in the end. This link will get you ten for little over a buck: https://www.aliexpress.us/item/3256805313463226.html?spm=a2g0o.detail.0.0.40f627a4iGoazw&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.362094.0&scm_id=1007.40050.362094.0&scm-url=1007.40050.362094.0&pvid=d7c87d8e-09c6-4599-a202-66c954861b20&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.362094.0,pvid:d7c87d8e-09c6-4599-a202-66c954861b20,tpp_buckets:668%232846%238107%231934&pdp_npi=4%40dis!CAD!0.79!0.79!!!0.57!!%402101ead817021479370337686e4193!12000033324248467!rec!US!100026910!
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