I am looking to get a constant, clean 12v from my cars 12v line. I am wondering if all I am in need of to pull this off would be a simple 12v fixed regulator?

The 12v would be hooked up to a pico motherboard (19v max input), 7" lcd monitor and an arduino.

I did find this schematic here:

So would a simple regulator be good or not? Will it need a heat sink?

 

Will it need a heat sink?

Yes! The system voltage could be as high as 15V or so. Dropping 3V at 5A will generate 15W of heat to be dissipated. Kind of a lot. Of course if your load is much less than 5A, the power as heat will be less.

I'll leave it to others to comment on your zener regulator strategy. Looks good to me, but that doesn't mean much.

You'll never get 5A through that 2N3005 with only a 1kΩ base resistor.

Now that I think about it, I'm not sure how well that arrangement can hold the base voltage steady if the load varies.

 

You need to specify how much current you require.

Here is a 3-terminal LDO voltage regulator good for 3A.

http://www.digikey.com/product-detail/en/MIC29300-12WU/576-2222-ND/1029108

Yes, you will need a heat sink.

 

Wondering why you need a clean 12V when the pico is rated to 19V..

 

Automotive environments are brutal; you may see drops below 10v when cranking and spikes exceeding 60v during load dumps. A simple linear regulator will waste some power, and won't be of any help during low voltage drops; you would need a switching regulator to handle that.

I'm on my cell, so don't have a circuit for you offhand.

 

SgtWookie! Good to see you around again!

The NUC is rated from 12v-19v. Not sure of the wattage but the old ones are rated at 65w and i have no idea how many amps. The LCD and arduino... well i really have no idea right now. Maybe 0.50amps for the LCD and less for that on the Ardunio.

Someone on another forum suggested this:

Let me know when you are able to get a schematic, SgtWookie!

And thats for the feedback, MrChips & wayneh.

 

Do you have a schematic yet, sgtWookie?

Thanks!

 

What's wrong with the LTC3780 schematic? It's so efficient, there will be practically no power dissipation, so no waste heat. You should get 12v out even if you're running the starter motor.

Arrow has the IC in stock for $7.64: http://components.arrow.com/part/detail/41629267S7869994N7433?region=na

 

You'd still need to protect it from a 60V spike, right?

 

You'd still need to protect it from a 60V spike, right?

Is it possible to get a 20-30volt Varistor to protect against those high spikes?

 

You'd still need to protect it from a 60V spike, right?

Yes, the LTC3780 is rated to 36V input. You could use a couple of 30v TVS diodes across the input to take care of spikes.

Here's a suitable thru-hole:
http://www.digikey.com/product-detail/en/P6KE30A-T/P6KE30ADICT-ND/150911
Surface mount:
http://www.digikey.com/product-detail/en/1SMB28AT3G/1SMB28AT3GOSCT-ND/917706