Is this another use for a dimmer - Electric blankets

After reading a few posts today about the use of dimmers and a statement that they are mainly for lights, and that someone has used them for fans with mixed results it got me thinking.

I am planning on using some GPO's on a relay for the bedrooms to turn electric blankets on an night and time off so even if you are out the bed is warm when you get home

Can a dimmer be used for an electric blanket. What I am thinking is that the blanket be left on full plugged into an outlet on a dimmer channel. Using a remote you can set the temp (presets like normal), but also use logic to adjust temp as the room temp changes. This would require a little tuning of course, but based on the fact that the bedding doesnt change too much, it shouldn't be too hard.

Just some very random thoughts of mine.

Mick

 

I have to throw my 2c worth in here Mick.

Please don't ever leave an electric blanket turned on when the house is unattended.

There are more house fires caused by electric blankets than you would believe.

 

Thanks guys - yes I am aware of that. It was more a way of getting my point across.

Mick

 

I'm not entirely sure what your point is/was, but yes, an electric blanket is a resistive load and thus entirely compatible with the dimmers, providing that the blanket load fits within that the dimmer is rated to supply.

However, there are logistical problems.

If you have a ordinary power outlet on the wall next to the bed, someone, somewhere is going to use it for a purpose for which it is not intended, and a dimmer may or may not approve of a vacuum cleaner / power drill / hair dryer / microwave / kettle / CFL bedlamp / whatever being plugged in. With luck, the channel MCB will catch any overload, but an unpleasant load may pop the triac.

There may even be regulatory probolems with having a 10A / 13A / 15A outlet that can only supply 1 amp.

And the point about fire risk is not to be underestimated. If I were to do this, I'd have an "arm" button next to the bed that has to be pushed each day once the husband / wife / maid has made the bed, to indicate it is safe to be heated, and not loaded with five suitcases full of clobber, which may cause undesirable things to happen.

In terms of regulating the power to the blanket, in my experience of electric blankets, I dont think its necessary. I like my half on number one, the missus likes hers on number two.

David.

 

Any "power point" that is not to be used for power should not allow a normal plug to be fitted. The easy solution (in Australia) is to use a Round Earth power outlet. This is extremely common in Hotels, etc where there is a switch on the wall near the door that turns on portable devices (table and floor lamps). This is completely legal, and the only safe way to do it.

My own blankets have digital displays, timers etc so there's no need to worry about Cbus control. As an aside, these blankets are DEFINITELY NOT a resistive load - the controllers are completely electronic so there's no way these "modern" blankets could be used on a dimmer anyway.

Cheers, JC

 

I have done this in my house for a couple of display cabinets and table lamps. I thought the other caveat was it had to be supplied with 2.5mm cable as well, but I'm not sure about that one.

 

The only downside is that you can always plug a two pin plug in without any consideration (such as a TV).

The round earth pin is not a catch all, but it does help. A totally different pin orientation is really what is required, but it would have to comply in all aspects.

You can use any cable size you like as long as it is rated for the intended load (and is protected accordingly). This is not so hard when using a dimmer as you know that you will only be using 1A. and 10A for a relay. Unlike your normal GPO's, where loads can vary, you really need a crystal ball to understand how the owner will be using them.

mick

 

We installed the power points with round earth pins at Auckland International Airport.
We did this because the cleaners would come along and unplug the flight information monitors so they could use their vacuum cleaners. There is nothing like being regularly called into work at 2:30 in the morning to just plug back in an unplugged monitor to make you want to find a solution. The round plug worked until they upgraded their vacuums with a model that did not need an earth pin. This now applies to lots of different appliances and could possibly damage the appliance (Brown Out).
Is the baby sitter going to know that it is controlled?

I would not feel easy turning a general power outlet into a dimmable outlet. It would make me happier if I could turn it into a permanent connect. (Heated towel rail type outlet for the non electrical people here)
Colin

 

This was entirely the reasononing behind my use of the word "ordinary".

Flash, John, very flash Mine are modern (defined as purchased recently) and are most definitely resistive loads, no smarts whatever. Not even the operator.....

 

Sunbeam won a design award for theirs :
http://www.designawards.com.au/ADA/03-04/Consumer/046/046.htm
- But we purchased Linda brand (sold by Mistral, which is kinda like Clipsal) as they were cheaper

Seriously, these things are the BEST THING I've used for a while, a perfect application of electronic controls. Hit the ON button and they Preheat (for your defined time at your defined level) then drop down to standard temp. The "on" time is separately programmed - No matter what, it always automatically switches off.

Completely covers all aspects of control (except remote turn-on), right on the cord control ! Digital display, and the programming is basically it remembering what you asked for last time, so even my non-techie GF can manage it easily.

We never even think about it - just walk in about 15mins before bed and press "ON" on both controls, then let them do everything else for themselves incl. switch-off.

OK these are fairly high-end products, but nowhere near as expensive as trying to integrate them to same level using Cbus etc...

JC.

PS: No telephone interface or blind controls in them, unfortunately

 

What, manual control...... how quaint

 

This is the type of thing I was getting at. The benefit I was seeing was that you are travelling home and you could call in and turn them on to have a toasty bed for when you got there. Yeah there are issue, but it was more the priciple I was trying to get at. In your case an outlet on a relay would work well. As Rohan said, how quaint - seems to go against the grain a little in this group

Set them up on a relay and use your remote from the longe room to turn them on. A timer on the relay (dimmer) could also act as a bit of extra protection if the timer in the unit failed. Although if you are like me and its the middle of winter and the fire is burining nicely it is very hard to pull yourself off the couch and go to a cold room.

Where does it end - who knows, we can go around like this forever, the main thing it that you are happy with what you have done and it is safe so that you dont hurt anyone