Solved ignition noise problem...thanks all!

[Sandy]

The 7805 has a much higher drop out voltage then the 2940, that is one key
area, as if you watch the voltage as you crank the engine it can get on the
edge of be in that GREY area where the regulator wont work. Also the 2940
and other automotive series regs are usually reverse and load dump
protected, so when some coned shaped hat show that you car can run without
a battery, you don't fry every thing. Lastly the Temp specs for the generic
7805 unless mil spec is typically commercial rated or less, while the
2940's are rated at lest 0-125C as the standard part. And after reading all
this crap, they are drop in for the standard 3 pin regs.

Sandy

>> Just curious, I been using the 7805 without problems, and curious
>> if the LM2940-5 is a physical drop in replacement ie TO-220 case,
>> I think is the term..    Still need caps across it for oscillations?.
>> Any experience tips from using it, ie 100mfd for+aft big enough?.
>> TIA
>> Bruce
>