Thanks to Steve and Jayne I received the new HP488 develop board. Windows recognise it perfectly and a pre-programmed PIC operate correctly but If I connect The PSU jack (regulated 13,5V power supply), the LM7805 IC become VERY HOT in few seconds even if I remove the programmed IC. I measured 420mA out of my power supply. Note there aren't any other component "hot" so I don't know where is te mistake.
PS
J20 usb
J 29 PSU
LVP DISABLED
Overheat Lm7805
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Steve
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Re: Overheat Lm7805
Have you trie dthe suggestion here:
http://www.matrixmultimedia.com/mmforum ... &sk=t&sd=a
http://www.matrixmultimedia.com/mmforum ... &sk=t&sd=a
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psf
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Re: Overheat Lm7805
Unbelivable true, note that even a LM317 power regulator (and a rectifier with 4700microF capacitor) "create" a ripple. The voltage of power input should be 14,5 as described or 14 + 1.2 (0.6 X 2) of bridge rectifier? Thanks for help.