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I would like to run my mini-PC (as opposed to Raspberry Pi) in my car to run Tuner Studio. I have a MS3/MS3x. I live in the hot Texas sun, and I hear so many people experiencing over-heating issues with the Raspberry Pi's (especially if you enclose them in a case). The mini-PC I have has pretty decent specs and already comes in a case with plenty of cooling holes so I'd like to give it a shot. It has a solid state 64g drive so it boots up very quickly.
Mini-PC = 12v input
Rasperry Pi = 5V input (most people use a 12v to 5v DC converter to power both the Pi and the LCD screen together)
I'll have to power my mini-PC and LCD screen separately. The LCD screen is a 5v input.
I like that the mini-PC is Windows 10 based as opposed to Linux and I've had great success with it so far... even loaded firmware on the MS3 and ran Tuner Studio with it already (in house, outside of car using the power adapter that came with the mini-PC). I cannot use this power adapter in the car because it is made for AC house power.
YOU would think that with sooo many 12v home electronics out there, that there would be an easy, straight-forward, and safe solution to be able to power them in a car as well.
The problem is that many of the reviews of the buck converters are bad . I can only rely on my multi-meter to test for 12v but that doesn't help much, honestly. I see people in the reviews of the buck converters using oscilloscopes, thermal tests, and other power testers which I do not have.
I want to be sure I don't fry something in the car.
Anyone recommend a way to power my 12v PC in my car?
Keep in mind... with the alternator running it's seeing over 13.8v when car is running. When car is not running it's seeing just over 12v. These buck converters require a minimum of 1v differential between the input and output.
What are the input specs on the PC 12v input? It's gotta be +/- some number of volts, maybe it'll take the 12-14v available from your alternator.
Also, remember that those cheap buck converters may not provide enough current to run the PC, or may allow the output voltage to drop dramatically under momentary loads. That's no bueno. You don't mention which PC you'll be using, but a quick Google on the brand shown says that it expects 1.5A. I'd treat that as an absolute minimum for any 12v/12v power supply you choose and would probably double it just to be sure that it'll handle load spikes OK, particularly when then engine is off.
Edited to add - you're unlikely to fry anything on the car side unless you're truly dumb, but you may fry the mini-pc if it can't tolerate the input voltage you're giving it.
I'm no expert, but I think you want a sepic or buck/boost converter. I don't know of anything off the shelf, other than maybe a eval board? This one is only 12W, though. First one that popped on google.
And you can totally screw with the electronics in the car screwing around, especially with switching converters. Those little tiny things you see all over the internet are about the worst, terribly optimized in about every conceivable way. Those are buck or boost, not both. Running a buck, then a boost would probably work while being terribly inefficient. There's a strong potential you'll put high frequency noise onto the 12V rail, if it matters or not is a whole other deal. More likely you'll just fry whatever you try and run off "12V."
I'd feel pretty safe copying one of TI's or some other manufacturer's reference designs, though.
What are the input specs on the PC 12v input? It's gotta be +/- some number of volts, maybe it'll take the 12-14v available from your alternator.
Also, remember that those cheap buck converters may not provide enough current to run the PC, or may allow the output voltage to drop dramatically under momentary loads. That's no bueno. You don't mention which PC you'll be using, but a quick Google on the brand shown says that it expects 1.5A. I'd treat that as an absolute minimum for any 12v/12v power supply you choose and would probably double it just to be sure that it'll handle load spikes OK, particularly when then engine is off.
Edited to add - you're unlikely to fry anything on the car side unless you're truly dumb, but you may fry the mini-pc if it can't tolerate the input voltage you're giving it.
I'm providing a picture of the back of the mini-PC. It say's 12V 2A. The PC is Tanix Model TX85 and here are the specs
Intel Atom X5 Z8350 Intel HD Graphics 4GB RAM + 64GB EMMC 2.4GHz + 5.8GHz WiFi 1000Mbps USB3.0 BT4.0 Support Windows 10
I understand I probably won't fry anything on the car side but I'm mostly worried about frying the PC or having the cheap buck converter messing something up. You would THINK there would be an easy proven way to run a 12V PC in a car in the year 2020... but there still doesn't seem to be a clear way ...
In response to your question above, no, it's not a problem. The power supply's rated amperage rating can be arbitrarily high. The device will only draw as much current as it needs.
Do you have space to hide a small 12v SLA battery, which is connected to an "active in run" circuit? That's a good start, to keep the machine fed with power during cranking, and let it shut down properly after key-off.
I fancy person might put a 5v relay between the battery and the regulator, driven by the PC's USB, with a bypass button to get it to turn on initially.
In response to your question above, no, it's not a problem. The power supply's rated amperage rating can be arbitrarily high. The device will only draw as much current as it needs.
Do you have space to hide a small 12v SLA battery, which is connected to an "active in run" circuit? That's a good start, to keep the machine fed with power during cranking, and let it shut down properly after key-off.
I fancy person might put a 5v relay between the battery and the regulator, driven by the PC's USB, with a bypass button to get it to turn on initially.
Thank you for your response , I like your idea, although I think for now I'll just power on the mini-PC and LCD monitor after the car starts (since I'm primarily using it for gauge read-out via tuner studio and for street tuning via auto-tune). I went ahead and ordered the Car DC 12V 4A Voltage Stabilizer Surge Protector Power Supply Regulator for Auto to power up the mini-PC (which I will have to turn the power button on the mini-PC after the car starts). The LCD monitor will be powered by this 12v to 5v dc to dc converter. If you all would like, I can do a follow up post after I get this up and running with the MS3 and the car idling if you all would like to know more about it.
Why?
I like that I can use the $85 mini-PC for my two cars running Megasquirt, as well as for home tasks, and I can take it in and out of the car. The 7" monitor(s) will stay in the cars. Why am I doing this? Budget reasons . I can throw a couple spade connectors on the power/ground supply side of the PC and take it in and out of the cars as I please. I'll use fuses and wire both the mini-PC and LCD with switches that way they don't stay hot with electricity all the time. I can simply use a bluetooth keyboard and bluetooth mouse with it's bluetooth receiver always plugged into the mini-pc (this way I can be mobile with my keyboard and mouse no matter if I want to run the setup in the cars or take it in the house and work in the home). Call me dumb?
I really, really appreciate all of the advice and links in this post thank you
12-18-2020, 03:12 PM
How to power 12v PC to run Tuner Studio?
. I can only rely on my multi-meter to test for 12v but that doesn't help much, honestly. I see people in the reviews of the buck converters using oscilloscopes, thermal tests, and other power testers which I do not have. 
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but I'm mostly worried about frying the PC or having the cheap buck converter messing something up. You would THINK there would be an easy proven way to run a 12V PC in a car in the year 2020... but there still doesn't seem to be a clear way 
...
, I like your idea, although I think for now I'll just power on the mini-PC and LCD monitor after the car starts (since I'm primarily using it for gauge read-out via tuner studio and for street tuning via auto-tune). I went ahead and ordered the Car DC 12V 4A Voltage Stabilizer Surge Protector Power Supply Regulator for Auto to power up the mini-PC (which I will have to turn the power button on the mini-PC after the car starts). The LCD monitor will be powered by this 12v to 5v dc to dc converter. If you all would like, I can do a follow up post after I get this up and running with the MS3 and the car idling if you all would like to know more about it.
. I can throw a couple spade connectors on the power/ground supply side of the PC and take it in and out of the cars as I please. I'll use fuses and wire both the mini-PC and LCD with switches that way they don't stay hot with electricity all the time. I can simply use a bluetooth keyboard and bluetooth mouse with it's bluetooth receiver always plugged into the mini-pc (this way I can be mobile with my keyboard and mouse no matter if I want to run the setup in the cars or take it in the house and work in the home). Call me dumb? 
