C
Captain Dondo
I am about to install some consumer electronics gear in a car. One
piece runs on 12VDC the other on 5VDC.
I know just enough about car electrical systems to be dangerous, but....
I figure that the 13.8 VDC in a car is pretty dirty, and probably not
really stable, so I want to use some voltage regulators and filters.
The filters I actually have - they're just basic cheap coil/cap type stuff.
I'm thinking about the regulators... Since I don't need much current, I
figure I can use something like a L4940V12 and a L4940V5 - both of which
are self-contained 12VDC and 5DV regulators. More info on them here:
<http://www.st.com/stonline/books/ascii/docs/2141.htm>
I figure I can scrounge a heatsink from an old CPU for a few bucks...
I have two questions:
Are these likely to be effective? And, just how much external circuitry
do I have to have to make these work in a minimal way? The spec sheet
just shows two caps. Will this be enough?
I plan to connect these to my filtered DC, so the worst of the ignition
noise should be gone.
But do I need a zener to ground as well? Any suggestions?
Thanks,
--Yan
piece runs on 12VDC the other on 5VDC.
I know just enough about car electrical systems to be dangerous, but....
I figure that the 13.8 VDC in a car is pretty dirty, and probably not
really stable, so I want to use some voltage regulators and filters.
The filters I actually have - they're just basic cheap coil/cap type stuff.
I'm thinking about the regulators... Since I don't need much current, I
figure I can use something like a L4940V12 and a L4940V5 - both of which
are self-contained 12VDC and 5DV regulators. More info on them here:
<http://www.st.com/stonline/books/ascii/docs/2141.htm>
I figure I can scrounge a heatsink from an old CPU for a few bucks...
I have two questions:
Are these likely to be effective? And, just how much external circuitry
do I have to have to make these work in a minimal way? The spec sheet
just shows two caps. Will this be enough?
I plan to connect these to my filtered DC, so the worst of the ignition
noise should be gone.
But do I need a zener to ground as well? Any suggestions?
Thanks,
--Yan
