Mini HPT

[kamaangir]

It's son of Biohazard.

I strongly suspect that I am older than he/she so your suggestion is not possible! 

Back to your oil scalding device, I suspect its the pot that controls the heat. I remember I had a soldering iron with a similar set up.

[Jamesrl]

Back to your oil scalding device, I suspect its the pot that controls the heat. I remember I had a soldering iron with a similar set up.

I've never seen a soldering iron with a pot on it and believe me I've seen more different types of soldering irons than you can shake a stick at.

[kamaangir]

I meant the circuitry.......  

When is the nurse coming round with your appy pills?

[K.H]

When is the nurse coming round with your appy pills?

Probably after his sexual harassment hearing

[Jamesrl]

Probably after his sexual harassment hearing

That wouldn't happen, I'm important.

[Head Womble]

Back to your oil scalding device, I suspect its the pot that controls the heat. I remember I had a soldering iron with a similar set up.

I've never seen a soldering iron with a pot on it and believe me I've seen more different types of soldering irons than you can shake a stick at.

But have you ever seen a soldering Iranian ?

[Jamesrl]

But have you ever seen a soldering Iranian ?

I've seen a garden walk, I heard a diamond ring but I ain't never seen an soldering Iranian.

[Julian]

It's not obvious how the control system on that works - are there any markings on the TO220 device?  (The sticky out one with three legs!)

I'll have a look tomorrow.

There you go, I didn't think my camera was this good ... got it off my daughter who was going to throw it away because the battery had died.

Is it any more help?

[greasemonkey]

I've tried to do a HPT a few times, never found it very successful. I'd rather take a sample of the oil, add 10% petrol, and see what drops out after 24 hours.

[Julian]

Bump ... Tony is the photo above any more help or is it just a rubbish control system that's beyond salvage as you intimated above?

[Tony]

One of these fellows then - a triac.



It'll be something very similar to this:

http://www.electronicecircuits.com/electronic-circuits/filament-light-dimmer-circuit

You can either change the C (smaller capacitance will give more on time, or larger C will give less on time).  Or the variable resistor - larger R will give less on time.  If you can find the value of the variable resistor track you could hack another fixed resistor in series with it to also slow the charging of C.

[Julian]

Thanks Tony.  So, modification would be possible, that's great.

I'll dismantle it further and see if I can relate the bits to the diagram.  Preempting any physical modifications and looking at the diagram, could I increase the value of R1 or, if R1 isn't fitted, fit one?

[Tony]

Yes exactly that Julian.  Good luck and let us know how you get on.

If all else fails you could try an actual light dimmer circuit from a light dimmer to see if that helps at all (they do, after all, turn all the way down).

[Julian]

I can work that out only from what you wrote ... I still don't have a clue as to how the circuit works!


Good thought about the light dimmer, but would it take the load.  The most I think they will take is about 200 watts.

Don't answer that ... yet, I'll see if I can find out what my pot's rated at.

[Julian]

D'oh ... just realised ... you meant in place of the existing pot didn't you.