Jaycar's Adjustable Temperature Switch

[PrIsMaTiC]

Take a look at this adjustable temperature switch kit offered by Jaycar.

http://www.jaycarelectronics.com/produc ... eywords=KC%

Is there a schematic of this kit (or similar) floating around on the web?
Maybe a company in the USA sells a kit just like this one. Haven't
found any yet.

[Engineer1138]

What were you planning on using it for?

I've been playing with a similar design using an AD592 and a few analog components. My plan is to post the schematic for free and if anyone wants, they can buy a parts kit from me (I have lots of parts I need to get out of my basement), but I just haven't had a lot of free time recently.

If you haven't found one by the weekend, PM me and I'll try to get my butt in gear and finish it

[PrIsMaTiC]

I can't even remember all the different types of temperature sensing
circuits I breadboarded many years ago. I liked all things mechanical
and electrical! Failure meant nothing to me. I just moved on to the next
fascinating project.

I've got two cars. One has a problem that caused a few major recalls
by the manufacturer. In warm weather the car is always pushing the
limits of it's cooling system. A computer module controls the on-off
cycling of a two speed electric fan. The fan is not the problem. It has
more than enough power to dump the heat. The module, along with
it's ECT (Engine Coolant Temperature Sensor) do a lousy job of turning
the fan on when its needed most. The manufacturer's solution was
to replace the module and sensor with the same junk.

I know I can design and build a circuit that will do the job. I've always
done a lot of the repair work on my own vehicles. It amazes me that
any complex electronic circuit can function under the hellacious conditions
found under the hood of car. Heat, freezing cold, corrosive chemicals,
constant bouncing and vibrating, plus a whole lot of RFI/EMI.

I was hoping I could find a kit or module that would lessen the amount of
precious time I would have to dedicate to the resolving this problem.

Recently, I cut down a large tree in my backyard. It was very dead.
The work was exhausting and somewhat dangerous. Each time I think
about this problem with my car I feel like I just ran a 25 mile marathon.
I guess I am getting old!

[philba]

just a thought. It's only 19 bucks - just buy it and try it out. If it works, done. If it doesn't work you are out 19 and not much time but you've probably learned a lot in the process.

by the way, I can't help but think the hardest part of the problem is figuring out where and how to attach the sensor.

[bodgy]

This is not the same - but here is a link to another kit with schematic pdf.

With this one it would be easy to buy the parts. To make it adjustable you play about with VR1!


http://www.oatleyelectronics.com/pdf/k101.pdf

This may be the same as that produced by DIY kits of Hong Kong.

Of course, I think you might find an adjustable temperature device in this months N&V, though it'd be more expensive than the Jaycar or Oately kit.


Colin