Dew controler based LED dimmers

[Stargazer33]

That should say: 'Looks naff now next to Dave's' ?!?

[Epicyclus Dave]

id call mine rough as a badgers rear end, but functional .

Getting one finished and using it is the main thing , Good stuff

Dave.

[Stargazer33]

I can't say that I have ever been that close to a badgers rear end to notice how rough it is, so I will bow to your superior knowledge! Still looks very good to me.

Bryan

[Cubemaster]

Ordered my dimmers on 2nd Sept and they only arrived today! Now I can finally finish my power distribution box

[BargeGazer]

Great cheap dew controllers. Don't be clever like me though and assume you can tie all the -ve terminals together and just separate the +ve outputs. Both sides of the outputs must be kept separate!

[Gina]

In fact, the positives are common. If you look at the circuit board the +ve input goes straight to the +ve output - the control is in the -ve side.

[BargeGazer]

That's Chinese for you!

[Gina]

Not really I used the same method for PWM Peltier TEC control. The power is controlled by a power MOSFET with the load in the drain (anode) circuit. The source (cathode) goes to earth/ground and the PWM control signal goes between the gate and source/ground. It's the standard arrangement.

[Cubemaster]

Circuits built.. Just to figure out how and where to fix them

[Cubemaster]

Finally done and I really enjoyed building this!

Thanks for all your help and inspiration everyone

[Freff]

Nice job, very nice job.

[Gina]

Very neat - great job

[Cubemaster]

Nice job, very nice job.

Very neat - great job

Thanks Peeps

Gina. Those 2.2k resistors are spot on! Thanks

Dave

[Epicyclus Dave]

Looks great , you'll be looking forward to the next clear night for a test run .

Dave.

[IanL]

Just finished building my three channel controller; eBay dimmers, large Maplin project box, LEDs + 2K resistors, 2A panel fuses. Also slotted in my Arduino Uno board for a future stepper motor focus upgrade later.

Voltages are a little odd though, getting -1v at the lowest Pot setting through to about 12.5v a the top end. Just need to build my heater tapes now and I am all set.

[Gina]

Another nice neat dew controller box

[Epicyclus Dave]

great looking controller there

If your having trouble with the heat at maximum setting have a look a couple of pages back for the pot mod i needed to do.

Add a 680 ohm resistor on the max lug on the control pot , the picture of your original led dim box shows the black printed curve, that's the action of the control pot ..9 o clock = min to 3 o clock = max when using a dew band , the heat tails off after the 3 o clock position , add the 680 ohm as my diagram and the max heat will be at max pot turn ,

Dave.

[moxican]

Could this work as a controller for dew heater straps?

http://www.ebay.com/itm/160816907893?var=460077054980

[malc-c]

Two issues with that - it's a thermostat so you need to know and set the dew point temperature each time you use it. And second, it's another wire that needs to be placed on the scope as it needs to monitor the temp of the dew heater to ensure it meets the set point. But other than that it would work.

Oh and I noticed it states a 12v relay, so the constant ticking as it switches on and off in the dead of night might be noisy

[Gina]

I thought of making a set point temperature controlled dew heater system with several dew heaters controlled by an Arduino but decided it was overkill - the temperature is not that critical and simple manual control using those cheap Chinese units put in a box like all the schemes above would be perfectly adequate.

[moxican]

Thanks guys. I'll stick to the controller this whole thread started with. More simple.

[Duke2k]

Hi all, I have been following this post for a few weeks now while waiting for my dimmers to arrive. I have got four dimmers which will all be used for dew heaters, and I understand how to wire these up but I also need 2x 12v outputs 1x 6v output and 1x 7.4v output. I have a limited knowledge of electronics and wondered if anyone could tell me how to drop the 12v to 6v and 7.4volts? I also noticed a post about adding a resistor to the pot to give maximum output at the maximum setting but I dont really understand this.

[malc-c]

To drop 12v to 6v use a 7806 linear regulator. However to drop 12v to 7.4v might be harder, but there are lots of products in the RC market that do this... just google 7.4v regulator

[Cubemaster]

If you have a look at mine the 3rd socket from the left is a 6v circuit using the 7806 as Malc_c suggested.

[Gina]

If you want to go for a linear regulator , an LM317 plus two resistors will give you any voltage from 1.25v to a volt or so below your supply voltage.