PTC Thermistor heater for diesel filer ?

[[email protected]]

I want to build a 12v PTC thermistor heater to warm the diesel fuel
filter( self regulating to 150-160F ) on an old Ford truck I have . I
think about 300 watts would be enough . I need some how-to advice and
sources for parts . - Thanks

 

[John Woodgate]

I read in sci.electronics.design that [email protected] wrote (in

I want to build a 12v PTC thermistor heater to warm the diesel fuel
filter( self regulating to 150-160F ) on an old Ford truck I have . I
think about 300 watts would be enough . I need some how-to advice and
sources for parts . - Thanks

Where will you get the necessary 25 A from, for long enough?

 

[[email protected]]

I will put it on a separate circuit on 10-12 ga wire fused at the
battery with a relay connected to the key switch .

 

[R]

[email protected] wrote in @f14g2000cwb.googlegroups.com:

I want to build a 12v PTC thermistor heater to warm the diesel fuel
filter( self regulating to 150-160F ) on an old Ford truck I have . I
think about 300 watts would be enough . I need some how-to advice and
sources for parts . - Thanks

150F seems excessive.

r

 

[Mark Jones]

I will put it on a separate circuit on 10-12 ga wire fused at the
battery with a relay connected to the key switch .

May I suggest you run it from a second starter solenoid, and run
that solenoid from a timer. Reset the timer when the car is running.

 

[[email protected]]

I plan to run a diesel / veg oil at some point in time and need those
temps to prevent gelling.

150F seems excessive.

 

[legg]

I want to build a 12v PTC thermistor heater to warm the diesel fuel
filter( self regulating to 150-160F ) on an old Ford truck I have . I
think about 300 watts would be enough . I need some how-to advice and
sources for parts . - Thanks

There are bimetalic switches rated at 16A, that can regulate as low as
70C +/- 5deg available from Cantherm.

http://www.thomastracking.com/dlcount.php?id=cantherm&url=/downloads/cantherm_a10.pdf

PTC heating elements aimed at 70C are pretty rare, particularly at the
lower voltage. Automotive crankcase and block heaters aim to keep
things barely above zero, and are standardly mains-supplied, for use
when vehcles are parked. 24V heaters (for truck battery systems) are
fairly common, but again are aimed at lower temperatures.

Because PTC characteristics are not ideal, the regulated temperature
will depend largely on the energy absorbed. PTCs are better
characterized as constant power dissipators, rather than ambient
temperature regulators, if the system is not closed.

(almost) commodity eavestroughs and pipes -

http://www.hitachi-cable.co.jp/en/review/19/review16.pdf

biomedical assemblies

http://www.dekko.com/clients/dekko_site/medical-devices/ptc-elements.shtml

A discrete sensor and heater might offer better versatility, while the
ptc elements and hardware are researched.

RL

 

[Mac]

I want to build a 12v PTC thermistor heater to warm the diesel fuel
filter( self regulating to 150-160F ) on an old Ford truck I have . I
think about 300 watts would be enough . I need some how-to advice and
sources for parts . - Thanks

300 Watts sounds like a lot to me, assuming you insulate the filter. (You
are going to insulate the filter, aren't you?)

Also, 150 F sounds kind of hot. Maybe you can add something else to the
fuel so that you don't need to maintain so high a temperature. (Ethanol?
Methanol?)

A lot of people are running diesel engines off of discarded deep-fry
oil nowadays, so I'm sure there are some good solutions out there
on the internet.

--Mac

 

[[email protected]]

Yes I am plaining insulate the filter . Most of my internet "research"
has revealled recommendations of a an optimum filter fuel l
temperature of 150-180 for vegetable oil (WVO, SVO ). I was hoping
that the PTC solution would but it sounds like they won't and I " A
discrete sensor and heater might offer better versatility ( eg glow
plug heater with furnace type - snap disc limit switch ) , while the
ptc elements and hardware are researched. But There some 12 v higher
temperature PTC s do exist out there ( used 12 volt coffee mugs etc ,
like those here -
http://www.roadtrucker.com/12-volt-kitchen-1.htm , so I am still
interested in the PTC method .