TheBackShed.com

Forum Index : Microcontroller and PC projects : How Hot

Author

Message

heppy36

Regular Member

Joined: 29/07/2011
Location: Australia
Posts: 54

Posted: 07:41pm 05 Jan 2013

Copy link to clipboard

Print this post

Hi all,I am using my maximite im my car,it monitors a lot of things,I have connected it up to a small reverse screen,
Can anyone tell how hot the reg should get?as I run up to 14V in the car it gets realy hot.
I have place a small heat sink on it but I cant hold my finger on it for long?
Thank you
Martin

Heppy

TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 5913

Posted: 07:50pm 05 Jan 2013

Copy link to clipboard

Print this post

Running off 14V it will get hot.
You could put a resistor in series to drop the voltage.
A 27 or 33 ohm, 2 or 5 watt resistor depending on the current draw which depends on your 'extras'.
I prefer to put a 8V regulator in to drop the voltage in two stages. The 8V also comes in handy for my peripheral circuits.

Jim

VK7JH
MMedit MMBasic Help

CircuitGizmos

Guru

Joined: 08/09/2011
Location: United States
Posts: 1421

Posted: 07:15am 06 Jan 2013

Copy link to clipboard

Print this post

Which Maximite? The CGCOLORMAX handles 8-18V DC so that it can be used in a car.

Otherwise TassyJim is right with using a series of regulators.

Micromites and Maximites! - Beginning Maximite

donmck

Guru

Joined: 09/06/2011
Location: Australia
Posts: 1310

Posted: 10:50am 06 Jan 2013

Copy link to clipboard

Print this post

The DuinoMite standard has provision for battery backup with automatic power source change, i.e. you can power this board by External power supply 9-30VDC, USB, or battery, the power switching is automatic.

http://www.dontronics-shop.com/olimex-duinomite.html

At $25, this has to be cheaper than you can actually purchase the individual parts to build one. You can hardly buy a PCB and a programmed PIC32 chip at this price.

Can be loaded with DuinoMite Basic, or MaxiMite Basic, as Geoff Graham has written a special version to offer limited support for the DuinoMite boards.

Don...

https://www.32v8.com/1

TassyJim

Guru

Joined: 07/08/2011
Location: Australia
Posts: 5913

Posted: 11:41am 06 Jan 2013

Copy link to clipboard

Print this post

The other way to save all that heat is to use a switching regulator, either direct to 5V or to 8V and keep the on board regulator for the final step.

Jim

VK7JH
MMedit MMBasic Help

heppy36

Regular Member

Joined: 29/07/2011
Location: Australia
Posts: 54

Posted: 09:31pm 06 Jan 2013

Copy link to clipboard

Print this post

Thanks its is the original one,I used the resistor and it made a huge difference

Heppy

MOBI
Guru

Joined: 02/12/2012
Location: Australia
Posts: 819

Posted: 12:22am 07 Jan 2013

Copy link to clipboard

Print this post

heppy36 said Hi all,I am using my maximite im my car,it monitors a lot of things

Hi, may I ask what it is you are monitoring and how? I would like to get into OBDII car diagnostic systems for, if nothing else but to make it work from the ground up rather than to buy a prefabricated system.

David M.

heppy36

Regular Member

Joined: 29/07/2011
Location: Australia
Posts: 54

Posted: 10:07pm 07 Jan 2013

Copy link to clipboard

Print this post

Hi I only monitor the fuel,I have 2 tanks (one reserve)which it cuts the pump off at a certain level,and battery and brake problem .
Not as much as I could,but the fuel system is the main one
Cheers

Heppy

MOBI
Guru

Joined: 02/12/2012
Location: Australia
Posts: 819

Posted: 10:42pm 07 Jan 2013

Copy link to clipboard

Print this post

Hi Heppy,

Dou you do any of the monitoring using the On Board Diagnostics socket or just direct lines to the various functions?

David M.

heppy36

Regular Member

Joined: 29/07/2011
Location: Australia
Posts: 54

Posted: 12:05am 08 Jan 2013

Copy link to clipboard

Print this post

Not yet,I will try a bit latter

Heppy

JohnS
Guru

Joined: 18/11/2011
Location: United Kingdom
Posts: 3663

Posted: 06:02am 08 Jan 2013

Copy link to clipboard

Print this post

One way would be an ELM device so that the 'mite can talk to it. I suppose a serial ELM would be easier than the now very common ELM327 (for which you'd need USB host in MMBasic).

(The ELM is just an 8-bit PIC with some very good software.)

Or, interface to the OBD II socket / the bus(es) in the car but some of them are awkward (such as needing 12V-signalling) especially from a 'mite with MMBasic. (Well, maybe CAN would be OK.)

JohnEdited by JohnS 2013-01-09

MOBI
Guru

Joined: 02/12/2012
Location: Australia
Posts: 819

Posted: 12:39pm 08 Jan 2013

Copy link to clipboard

Print this post

John said Or, interface to the OBD II socket / the bus(es) in the car

Hi John,

That is my intention. It is not a project that I intend to do "right now" as I am still in information gather mode and have to get to grips with the colour mites when they arrive first.

I will have no trouble interfacing to 12v signalling etc.

Have you done any playing with the OBD II system?

David M.

bigmik

Guru

Joined: 20/06/2011
Location: Australia
Posts: 2870

Posted: 08:19pm 08 Jan 2013

Copy link to clipboard

Print this post

heppy36 said Thanks its is the original one,I used the resistor and it made a huge difference

Hi Heppy,

You can always get a car cig. lighter adapter like this one

Car Lighter Adapter

This one `supposedly' supplies 2A at 5v.. They generally (read almost always these days) are switching types so no heat (Unless overloaded).

If you have the ORIGINAL Silcon chip design then you just select JP1 for USB power and use a USB to B type cable such as this one.. neat and easy.

USB Cable

regards,

Mick

Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<<

Print this page

To reply to this topic, you need to log in.