Nigel Goodwin Super Moderator Most Helpful Member Feb 22, 2007 #22 For a start measure the current it takes from the 7805, first without the backlight, then with it.
ikalogic Member Feb 22, 2007 #23 i never actually done the calculations...but a project with 9V battery feeding a micro controller, an LCD with white backlight, and IR proximity sensor ABSOLUTLEY needed a heat sink...
i never actually done the calculations...but a project with 9V battery feeding a micro controller, an LCD with white backlight, and IR proximity sensor ABSOLUTLEY needed a heat sink...
desperadogear New Member Feb 26, 2007 #24 For a start measure the current it takes from the 7805, first without the backlight, then with it. Click to expand... im really sorry if i was late to follow up.i got current measurement as 600 mA..
For a start measure the current it takes from the 7805, first without the backlight, then with it. Click to expand... im really sorry if i was late to follow up.i got current measurement as 600 mA..
audioguru Well-Known Member Most Helpful Member Feb 26, 2007 #25 The 7805 can easily supply 600mA. I think its input from the unregulated supply drops lower than its minimum input of 7.5V.
The 7805 can easily supply 600mA. I think its input from the unregulated supply drops lower than its minimum input of 7.5V.
Hero999 Banned Feb 28, 2007 #26 Try adding a 4700:mu:F capacitor in parallel with the input to the regulator.