Heating Element Control

[Centar]

FREEZINGO: I was trying to decide on which MOT to use for the inducer idea and couldn't decide until I looked at yours again and figured yours is as good as any...so I believe I have a close duplicate (see pic) and I will fill you in as I go.
1st thing is you'll need a small hand grinder (I use a 4 1/2 inch) and the 2 welds that hold the bottom plate on will have to be removed to remove the plate, then the 2 welds that hold the "I" section of the core to the "E" section will need to be removed to separate the core. At this point I think the windings could simply be press out of the "E" section (unhurt) and #10 stranded and insulated wire could be wound in the "E" section until full. Now we lay the "I" section back in place with a hinge on one end and a screw adjuster on the other so we can adjust the gap, thus the inducance , thus the "HEAT"....super simple....lets see who "experiments" with this 1st....

[Zzyzxx71]

I modified Odessa's original schematic with the common model #'s of the DIAC and the TRIAC - wanted to get a thumbs up from those of you who have a better grasp of this.

Thumbs up or am I gonna let the blue smoke out?

[Centar]

Zzyzxx71: Everything looks fine, except you may find that that 10k resister is a bit too much resistance to achieve 100% power, if not try a 6.8 k or so...

By the way in the pic you have the center and left connection used on the POT (as viewed from the front of the POT as in the pic), this will turn down the power as you turn up the POT, using the center and RIGHT connections would be the normal way of connecting it, and it would be best to terminate (connect) the (unused) left connection to the center one then as well, doing so helps reduce "noise" on the POT and makes for smoother control.
And the extra 1m resister(s) across the POT are for "EXPANDED RANGE" not linearity. It reduces or eliminates the "dead area" on the pot from min to whenever it comes on, thus giving the control over the whole range of the pot instead of just a portion.
Using a "LIN" POT (linear taper) as apposed to a "LOG" POT(audio taper) will make the control LINEAR.

[Zzyzxx71]

Fantastic information - thanks for the clarification. Time to do some ordering!

[Centar]

Spud1700: You fail to mention what exactly you are confused about...
If you care to share I will be happy to clarify.

[Pamulli]

Hi Centar,

Looking at the different diagrams, then people saying you need to have a "x" instead of the "a" which will do "Z" then the different diagrams, then I am thinking about 240v and the whole safety aspect ie electricution \ fire. I think this is one thing I will have to buy instead of mucking around with, I just put an ad in the for sale section seeing if someone wants to sell me one. I'll see how it goes and if I get any replies.

Spud take a look at this post in the New Distiller Reading lounge which uses a PSR-25. http://homedistiller.org/forum/viewtopi ... 83&start=0 This build costs a little more, but is dead simple with very few parts to buy.

[Centar]

Spud - I have designed what I believe to be a bullet proof TRIAC based controller (see my posts) with a couple of extra features that I was thinking of offering for sale.
I am almost finished the prototype and it could easily be adapted for 240 vac...
Have a look at my prototype in earlier posts and tell me what its worth to you...

[Filby]

OK just got some stuff from Jaycars (electronics stores in Oz).

1W 1MO Resistor
1W 10K Resistor
Y5U 100N 50V (104M) Capacitor
BTA16 (16 Amp 400v) Triac
ST2 Diac
500K Pot

Can someone who has put together Odessit's circuit (Clacker / Centar) make sure I got the right ones. Is 1W resistors OK for this?

Cheers!

Fil

[rad14701]

Filby, 1W components should be more than sufficient... One item you didn't mention the wattage rating for is your 500K potentiometer... Chances are good that it is 1/2W unless your ordered it rated as 1W or 2W...

[Filby]

Ah its 0.5watt... Is that ok?

[rad14701]

Ah its 0.5watt... Is that ok?

Should be fine but several members have had problems with 1W potentiometers recently... I think it had more to do with the brand than the wattage... I haven't tried a 240V controller but my 120V controllers don't have any problems with lower wattage potentiometers...

[Filby]

OK cheers for that Rad. Guess I'll give it a go and see what happens.

PS Just reading your All-Bran thread... cant wait to get one of those cranking!

[Zzyzxx71]

Zzyzxx71: Everything looks fine, except you may find that that 10k resister is a bit too much resistance to achieve 100% power, if not try a 6.8 k or so...

By the way in the pic you have the center and left connection used on the POT (as viewed from the front of the POT as in the pic), this will turn down the power as you turn up the POT, using the center and RIGHT connections would be the normal way of connecting it, and it would be best to terminate (connect) the (unused) left connection to the center one then as well, doing so helps reduce "noise" on the POT and makes for smoother control.
And the extra 1m resister(s) across the POT are for "EXPANDED RANGE" not linearity. It reduces or eliminates the "dead area" on the pot from min to whenever it comes on, thus giving the control over the whole range of the pot instead of just a portion.
Using a "LIN" POT (linear taper) as apposed to a "LOG" POT(audio taper) will make the control LINEAR.

OK lets play "Will Zzyzxx let the blue smoke out part duex.."

Below is how I currently have it mocked up (without the actual power line in place). I made the 3 adjustments recommended (Use of a linear pot, connection to the alternate lug of the pot, and use of a 6.8k resistor in place of the 10k)

Is this valid? I'm making the assumption that where indicated in the original schematic a component is connected where it would appear a wire is located, it's safe to connect to the eventual next connection (leg of next component).

If this should turn out to be a valid configuration, here are the parts listed - all from Mouser.

Potentiometer
Mouser #: 785-380C1500K
Desc.: Potentiometers 500 K Ohms 10% 2W Solder Lug

Capacitor
Mouser #: 647-QXK2G104KTPTZH
Desc.: Polyester Film Capacitors 400volts 0.1uF

6.8k Resistor
Mouser #: 660-MO2CT631R682J
Desc.: Metal Oxide Resistors 2W 6.8K 5%

Diac
Mouser #: 511-DB3TG
Desc.: Thyristors - Diacs, Sidacs, SCRs & Triacs 32 Volt Trigger

Triac
Mouser #: 576-Q6040J7
Desc.: Thyristors - Diacs, Sidacs, SCRs & Triacs 600V 40A

This make any sense?

[mtnmann]

One thing that jumps out Z is that your brown wire shouldn't be ground, it should be one leg of your 220V. Don't jumper your two hot legs together, that would cause problems. Run your ground wire directly to your hobby box (if metal) and then on to the boiler. In the end, you want both hot legs of your 220V connecting to your heating element (one directly and the other through your control components).

mm

[Zzyzxx71]

One thing that jumps out Z is that your brown wire shouldn't be ground, it should be one leg of your 220V. Don't jumper your two hot legs together, that would cause problems. Run your ground wire directly to your hobby box (if metal) and then on to the boiler. In the end, you want both hot legs of your 220V connecting to your heating element (one directly and the other through your control components).

mm

Schematic adjusted. Please advise.

[Centar]

Zzyxx71: To my knowledge a 240 VAC Socket in north America had GND, neutral,120, and 120 opposite phase on a dryer or stove socket. (4 connections)
You want the GND, neutral and either of the 120 connections.
If your out side north America the two holes are 240 and the 3rd (in the middle) hole is GND on a regular wall socket.

The updated schematic works if your out side north america.

I have added one SMALL addition to the circuit (black line) on the POT, this is the connection to keep the noise level on the POT down and makes for smother control....as small detail but usually overlooked even on a lot of "factory" gear...

[Zzyzxx71]

I live in Virginia, the dryer outlet only has 3 prongs - I ran a multimeter on them last night, both the positives are 120v lines.

The graphic representation of the plug matches the plug of the dryer I plan to take offline for my runs.

Please advise as to what needs to be done to make this work for a US 240v line.

[Centar]

Noticed another mistake on the drawing and corrected it for you...the wiring of the TRIAC was wrong....

[Centar]

What do you measure between the 2 NON ground connectionson on the the socket, on the AC scale of your meter? (there is no positive or negative as this is AC not DC)

[Tater]

I live in Virginia, the dryer outlet only has 3 prongs - I ran a multimeter on them last night, both the positives are 120v lines.

The graphic representation of the plug matches the plug of the dryer I plan to take offline for my runs.

Please advise as to what needs to be done to make this work for a US 240v line.

240 outlets will read 120 from each leg to neutral/ground read across both should 240

[Zzyzxx71]

What do you measure between the 2 NON ground connectionson on the the socket, on the AC scale of your meter? (there is no positive or negative as this is AC not DC)

240

[Centar]

OK, it appears that you do not have a neutral connection on that socket, just the 2 120 phases (180 degrees out of each other so you measure 240 between them) and the GND.
The Circuit wiring is correct for this in the drawing.

[Zzyzxx71]

OK, it appears that you do not have a neutral connection on that socket, just the 2 120 phases (180 degrees out of each other so you measure 240 between them) and the GND.
The Circuit wiring is correct for this in the drawing.

Excellent - I'll doublecheck the wiring of that resistor and get some pictures tonight with part links to Mouser.

[nath_44]

hey guys
im from oz using 240v power. building a power controler exactly like the first controler pamuli was building before he ditched the idea and went for the psr-25.

the whole thing went together fine and plugs in and turns on and didnt explode or let out smoke. i just have no adjustment in the pot.

checking the output of the box, it is the same if the pot is maximum or right down to minimum. hopefully i havent wasted my time coz the psr-25 seems a hell of alot easier to build. just need to fix the no range problem and im in buisiness!!!

if anyone can help it would be greatly appreciated! and yes ive read this thread back to front about 4 times, its massive.

thanx again

nath

[maheel]

[/quote]

hey team

last night i added the 1 W 1 mo resistor to my controller as i had non linear control.

i now have the above built but using a BTA26 triac

it is giving me linear control from about 140v -> 240 V based on my meter across the range of my pot.

next step is to fit it into a proper housing and fans and test using a boiler i have.

i will update the results once built

i used the design from odessit on page 31 of this thread and then added the Res that i think Zzyzxx71 proposed in the post on page 45

i am using 240 in OZ

WARNING !!! thats 240 in there and can kill !! be careful !!

[maheel]

i have a question about the triac

how do i test to confirm it is a isolated triac (this concerns me as i want isolated)

will a multimeter test across the the pole to the screw hole on each pole test prove it isolated ? (no resistance = isolated)

thanks

[rad14701]

i have a question about the triac

how do i test to confirm it is a isolated triac (this concerns me as i want isolated)

will a multimeter test across the the pole to the screw hole on each pole test prove it isolated ? (no resistance = isolated)

thanks

There should be no continuity between MT2 and the Tab on an isolated triac... There will be continuity on a non-isolated triac... The best way to tell, by far, is to check the datasheet for the triac itself... Virtually every electronic component has a PDF datasheet online...

[Filby]

Hrmm. Just finished building my Odessitt controller and im not getting any voltage change. It just sits at 230v regardless of where the POT is. Anyone have any ideas?

[Filby]

Think I found the problem. The guy gave me a 500ohm instead of a 500k POT. grrrrr

[rad14701]

Think I found the problem. The guy gave me a 500ohm instead of a 500k POT. grrrrr

That'll definitely do it... At least that won't cause any of the magic gray smoke to escape, rendering components worthless...