[chbot] Car 12v supply to 5v VCC.

[m.beckett at amuri.net]

+1 on the insulated. 

The vibration will range from fairly solid thumps to higher frequency
vibration, so rubber isolation will be your frend. 

Large components will appreciate a dab of a neutral cure silicon to help
them hold in place rather than relying on the component leads. 

The electrical noise is not likely to be any more than a normal car.
Race cars tend to have lower amperage alternators and the battery while
smaller is not as taxed as a normal car. 

Choke and capacitor (both large uF and smaller 0.1uF) across the
incoming should be enough. 

You can have someone check the 5v line with an oscilloscope if you have
any doubts. 

cheers 

Mark 

On 2019-07-07 13:32, Mark Atherton wrote: 

> Hi Daniel, 
> 
> First on your list would be my first choice, only because of the size of the regulator :) Also appears to be available on Trademe for a few-more-bucks https://www.trademe.co.nz/Browse/Listing.aspx?id=2212079583 [8]Datasheet for the XL6009 part is https://www.sunrom.com/get/283300 [9] indicates that the part is up to 94% efficient, and has a wide input range - 5-32V. Power spikes on car 12V rails can be quite large, so having a regulator that can tolerate a 32V spike is heading in the right direction. 
> 
> As Volker says, mechanical vibration can be a killer; all components need to be well secured; screwing or gluing modules to an insulated substrate may work well. 
> 
> Looks like a great project, links to photos of the project / vehicle appreciated. 
> 
> Regards, 
> 
> Mark 
> ------------------ 
> 
> On 7/07/2019 9:04 AM, Daniel Powell wrote: 
> 
>> Sorry for the intrusion with something bound to be a simplistic and rather rudimentary question given my lacklustre knowledge in electronics. 
>> 
>> I'm currently developing an ESP32 wrover, CAN Bus based dash for my race and rally car. I've already prototyped the dash using a Nano (which was too slow to capture every frame), then prototyped all but the 7 segments using the ESP32 (7 segments are 5v LL, ESP is 3.3). I've recently transferred it to protoboard (which I'm simply using as a flat substrate to level and mount the modules). I need to reliably convert the car 12v to the 5 volt required for VCC on most of my devices. I've purchased a handful of different aliexpress 3A DC to DC voltage stepdown regulators and a 1.8A buck converter. 
>> 
>> I wondered, given the noisy power environment of a race car, which, if any, would be best to provide 5v to my dash. 
>> 
>> Unfortunately my pics break the 40k email list limit, as such I'll include links to the devices. 
>> 
>> https://www.aliexpress.com/item/32280431843.html [4] , LM2596HVS, XL4005 and XL7015 
>> 
>> https://www.aliexpress.com/item/32961984080.html [5] , 12V LM7812 
>> 
>> https://www.aliexpress.com/item/32921703886.html [6] 
>> 
>> I've previously used a radio control UBEC to convert the car power to something I could pump into a raspberry pi, through it's on board conditioning, however I've never bothered to understand the fundamentals of power supply or how to smooth it such that I don't damage componentry. 
>> 
>> https://www.aliexpress.com/item/32920672534.html [7] 
>> 
>> Help genuinely appreciated. 
>> 
>> For those of you interested and wishing to punish yourselves further. 
>> TTGO ESP32 wrover (on board CAN) 
>> 
>> NS65HVD230 CAN transceiver. 
>> 
>> MAX2719 8x8 matrix (gear display) 
>> 
>> 4 x TM1637 - 7 segments (switched pages of 4 pressures/temps/alerts) 
>> 
>> 2 x 8 WS2812 Neopixles. (RPM and colour change for alerts). 
>> 
>> TXS018E 8 channel logic level converters (yet to test). 
>> 
>> Regards, 
>> Daniel Powell. 
>> 
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[4] https://www.aliexpress.com/item/32280431843.html
[5] https://www.aliexpress.com/item/32961984080.html
[6] https://www.aliexpress.com/item/32921703886.html
[7] https://www.aliexpress.com/item/32920672534.html
[8] https://www.trademe.co.nz/Browse/Listing.aspx?id=2212079583
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