Is it normal for the 7805 to get as hot as if i would touch it i would seriously burn myself, with a midiboxseq, 2 lcds 40x2, and all the other functions, leds etc being on ?
I’m wondering if i have something wrong somewhere,
I check the current flowing thru the entire circuit, but my multimeter wont let me measure currents higher than 200mA, and it goes above the 200mA.
i’m using a 1A 9v AC transformer
The front panel is ready, out of 3mm white plywood, lookin pretty neat! So now only this little issue and i’m off to make the case
You have to think of following: The whole circuit (without LEDs and backlighting) uses up app. 50 to 100 mA, but the LEDs are using about 100 mA and the backlight about 100-300 mA each. So you´re coming beyond the 500 mA like nothing. 500mA x 4 Volt downgrading the 9 Volt = 2 Watts pure heat.
Just *DO* use a heatsink on the 7805, then everythings OK.
You can leave those ones in there (also it´s not to normal that theyre getting hot). Normally they´re rated with a pretty good safety (if 1 Amp is stated, they take 1,5).
If they fry anyhow sometime, you can still change them. ;D
Anyhow, the best is a ready bridge recitifier (the round ones). They take up a lot (!). Never burnt one up to now (and thats some wonder with all those shorts I built)…
