Using a 12V automotive system to ultimately power a BS2.
·I am intending to use a Radio Shack 7805 in the TO220 case with a heat sink attached to bring the voltage from·an automotive system down to 5V to power a BS2 stamp.
·The recent comments that indicate spikes as high as 100V could occur when the vehicle brakes are applied and fry the 7805 are very worrying.
· Is there a way of placing something between the the automotive system and the 7805, to bring the input voltage that the 7805 might see to level that is acceptable to it?
· With all the electronics on modern cars I would assume there must be a way of protecting them from potential high voltage surges.
· I would appreciate any ideas.
·
·The recent comments that indicate spikes as high as 100V could occur when the vehicle brakes are applied and fry the 7805 are very worrying.
· Is there a way of placing something between the the automotive system and the 7805, to bring the input voltage that the 7805 might see to level that is acceptable to it?
· With all the electronics on modern cars I would assume there must be a way of protecting them from potential high voltage surges.
· I would appreciate any ideas.
·
Comments
http://sproggy.mp3car.com/psu.html
Hope this helps
Bob
At 08:19 AM 6/8/00 -0400, you wrote:
> an automotive system down to 5V to power a BS2 stamp. The recent
>comments that indicate spikes as high as 100V could occur when the vehicle
>brakes are applied and fry the 7805 are very worrying. Is there a way of
>placing something between the the automotive system and the 7805, to bring
>the input voltage that the 7805 might see to level that is acceptable to
>it? With all the electronics on modern cars I would assume there must be
>a way of protecting them from potential high voltage surges. I would
>appreciate any ideas.
>
This subject came up here recently, and someone suggested a National LM2940
regulator, which is designed for automotive apps. It has protection for
reverse polarity and voltage spikes. There are 5 to 15 volt versions
available at 1 amp. I believe DigiKey has them. This would probably be the
"cleanest" way to go.
Good luck,
Ray McArthur
I am intending to use a Radio Shack 7805 in the TO220 case with a heat sink
attached to bring the voltage from an automotive system down to 5V to power
a BS2 stamp.
The recent comments that indicate spikes as high as 100V could occur when
the vehicle brakes are applied and fry the 7805 are very worrying.
Is there a way of placing something between the the automotive system and
the 7805, to bring the input voltage that the 7805 might see to level that
is acceptable to it?
With all the electronics on modern cars I would assume there must be a way
of protecting them from potential high voltage surges.
I would appreciate any ideas.
At 08:19 AM 6/8/00 -0400, you wrote:
>>>>
> [size=-1] I am intending to use a Radio Shack 7805 in the TO220 case with a heat sink attached to bring the voltage from an automotive system down to 5V to power a BS2 stamp.
> The recent comments that indicate spikes as high as 100V could occur when the vehicle brakes are applied and fry the 7805 are very worrying.
> Is there a way of placing something between the the automotive system and the 7805, to bring the input voltage that the 7805 might see to level that is acceptable to it?
> With all the electronics on modern cars I would assume there must be a way of protecting them from potential high voltage surges.
> I would appreciate any ideas.
> [/size]
>
>
<<<<
Larry G. Nelson Sr.
mailto:L.Nelson@ieee.org
http://www.ultranet.com/~nr