Post ASLdXdZp2YBLQivdGC by davidlsparks@fosstodon.org
 (DIR) More posts by davidlsparks@fosstodon.org
 (DIR) Post #ASLWtip1WIVyOCceki by ian@mckellar.social
       2023-02-04T19:59:05Z
       
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       Hey electronics nerds. I want to get 5V DC to run a microcontroller & some peripherals (100-200mA) off a 9V DC supply. This is in an audio circuit so I don't want any (relatively) low frequency noise (I think).Can I use an LM7805 or do I have to design a buck converter?
       
 (DIR) Post #ASLdXdZp2YBLQivdGC by davidlsparks@fosstodon.org
       2023-02-04T21:13:31Z
       
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       @ian I would go with the 7805 unless you care about conversion efficiency. It can be tricky to deal with the noise from a buck converter, especially if you have variable loads.
       
 (DIR) Post #ASLjYarNE6VH1ByeOW by ian@mckellar.social
       2023-02-04T22:20:58Z
       
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       @davidlsparksThanks! I guess I'll see if the 7905 gets hot! I just don't have a whole lot of intuition in electronics stuff. I probably should have gone to class in 1995 so I didn't fail out of EE...
       
 (DIR) Post #ASLkgWS7b2gBcVVi1Q by davidlsparks@fosstodon.org
       2023-02-04T22:33:33Z
       
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       @ian It's been awhile, but at 9V in -> 5V out with a 200mA load, you'd be shedding 800mW of heat which should be within the package limits without a heat sink (assuming adequate ventilation). Here's a helpful link:https://protosupplies.com/product/voltage-regulator-7805-5v-1a/#:~:text=The%207805%20TO%2D220%20package,would%20need%20a%20heat%20sink.