New Gadget project started. Fridge fan controller. (1 Viewer)

OldAgeTravellers

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Hi Gromett,
You have been looking into power supplies recently. How difficult is it to design and build a reliable multiple voltage supply?
for my Satellite internet installation I have to use a number of the (probably Chinese) ciggy lighter socket converters one of which blew yesterday jumping a 3.5A & 10A fuse and blowing a 25amp fuse on the electroblok. (very confusing)
So I was thinking that perhaps a single box that could be designed well and even have a fan for cooling, perhaps running via one of your your fan controllers:).
The dish controller, tuner and TV are all 12volt so they are ok but:
The modem is 18volt 2A
The USB aerial wifi router is 9 volt 1.5A
The satellite WiFi router is 5 volt 2A
and a CO gas detector 9 volt 1.5 A. All plugged into the same multi ciggy outlet.
and I am thinking of changing to a better WiFi router 12volt 2A so the ability to change or select voltages would be useful.
What do you think, am I being daft? These cheap power converters do worry me a bit if I forget to turn the unit off and leave the van or go to bed they could possibly catch fire with serious damage and possible consequences.
Thanks for any input and sorry if it is going off topic but related. But it could actually be part of or linked to and monitored by your central monitoring system.
Steve
 
OP
OP
Gromett
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Hi @OldAgeTravellers,

I am not sure it would be a project I would be prepared to take on due to the risk involved. Remember this is just a bit of a hobby for me..

That said. The MC34063C chip is probably what you would want to look at. It is a switch mode PSU chip that only requires a handful of auxilary components to get working.
It can operate as a buck converter or a boost converter. It is only rated at 1.5Amps so you probably only want to use it for 750ma. However you can use an external MOSFET to boost it's current handling capabilities but would also need to add a heatsink.

This is the Datasheet for it.
http://www.onsemi.com/pub_link/Collateral/MC34063A-D.PDF

There may be a better solution but as I am only working with low currents of around 100-200ma with the fan system it is the only PSU chip I am familiar with so far apart from the 70xx series linear regulators. Those are however not suitable for your purposes nor would any linear regulator be.

The option would be to look for premade modules. There are lots of them on Ebay, Amazon and BangGood. If you search for either Boost converter for step up and Buck converter for step down. You should be able to pick up modules for £1-£2 each. Add heatsinks and a fan. Look for ones that have a small brass screw for adjusting the voltage though. Add a 12v fan to a bank of these and I think you would be good to go.

There are some really cheap and nasty combined buck/boost converters on ebay etc. I would avoid dual mode ones unless they are quality ones which won't be that cheap.

If you have any questions please let me know I have recently done a lot of research on SMPS so can probably answer most questions.
 
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Gromett
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PS: if you go to amazon with . You will loads of identical boards probably produced by an wun hung lo chinese manufacturer. They are pretty decent build quality but the specs aren't to be trusted. There is no way I would run these at 5 Amps. However for 2Amps I would have no problems using them. For 3A I would want a heatsink.
You will notice that there are cheap ones like this one for £2.99

Then there are other ones where they just appear to have stuck fairly decent heatsink on and designed their own board. You can see there is 3 different adjusters on. One will be for output voltage, the second for current limiting and the final one ???? Anyway this looks like a fairly decent one but it is £7.99

PS: I am not recommending either of these as I haven't bought nor tested them myself sorry.

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OldAgeTravellers

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No I wouldn't expect you to do it as a project, I think you have enough going on.
But as you have been looking at power supplies I wondered if you might have some useful input, as you have.
Now I know what to search for it will be a great deal easier.
Looks like a nice project to research while sitting in the sun in Spain.
Thanks for your help.
Steve
 
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Gromett
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ok. The last of the parts have finally arrived. It took 8 weeks for 2 of the parts to arrive from China. The rest arrived within 10 of ordering....

Soooo. I have work this week but will hopefully be making a start on it this weekend :D

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OP
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Gromett
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I have just spent an hour opening all the packages almost 30 of them and sorting out all the components and checking them off my list.
There are now too many to list and explain so I may even be forced to do a video of what I have and what they are used for. I might even do videos of the projects as they go through if there is any interest?

I can however confirm that all the components have now arrived apart from a packet of 20 x 5.5mm jack plugs I need for powering the projects in future. However for now I will just use screw terminals for testing purposes.

So the question is, any interest in bench videos of construction and operation?
 
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Gromett
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I just tried doing a quick intro video using my Galaxy Note 2. The test one I did was about 30 seconds long and worked ok. However I then did one on the various Arduinos and chips I have and it corrupted. I am not sure why but I think it was because I was saving to my SD card in the Note2 which maybe isn't a fast enough card.
12 minutes of video lost.

I have just ordered a new webcam based on recommendations which should hopefully be here tomorrow or Thursday.



This was recommended by another electronics guy who does youtube videos so hopefully it will be up to the job. It doesn't appear to have any lighting built in. So my first job may be to make some new lighting for videoing this stuff. Ho hum...

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OP
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The camera arrived yesterday and it is fantastic. Unfortunately the camera mount I bought for my phone doesn't fit. I am going to have to make a new mount :(

That polymorphic plastic will come in useful again.

Hoping to get that sorted today, first video tomorrow probably.

The first video I will do is a walkthrough of the various arduino and Atmel mcu's I have bought. I am open to suggestions for the next videos.
Components? sensors? Displays? IO devices etc etc.

I was going to make a video of me building the oscilloscope but I reckon it is 4+ hours work which would make for a very boring video watching me testing parts and soldering etc. I will probably just make a brief video of the parts then a video of the final thing working (or not) :p

Then it is onto the projects themselves.
 

Geo

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Only a certifiable Genius would be working on a fridge cooling system in the middle of winter:rofl::rofl::rofl:

I know ready for the summer but it sounds good:imoutahere:
 
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Gromett
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Only a certifiable Genius would be working on a fridge cooling system in the middle of winter:rofl::rofl::rofl:

I know ready for the summer but it sounds good:imoutahere:
Plans for this was started long ago. You do have a point but the initial testing wouldn't have been done behind a real fridge.

I am thinking about putting this down the queue of projects and bumping one of the others up.

It might actually make sense to do the multipoint temperature sensor now while we have a higher possibility of freezing temps.

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Jaws

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I use Cambridge Circuit Company for making my PCB's Karl..
They do tiny batches if you only need a few, and once the art work is done are very cheap indeed

http://www.cambridge-circuit.co.uk/

One of the products Jaws Motorcycles is well known for is a tail light with the Blackbird XX displaying..
Originally suggested and put together by a chap who started a company called Blackbird Spares ( hiya Pete if you ever see this post :) ) and further developed by myself after I bought the company, the boards for these cost less than a fiver a go and they are pretty big !
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Gromett
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I use Cambridge Circuit Company for making my PCB's Karl..
They do tiny batches if you only need a few, and once the art work is done are very cheap indeed

http://www.cambridge-circuit.co.uk/

They don't have an online quoting system :( I hate having to fill in forms and wait for replies..

I have been considering elecrow.com as they will do 10pcs of 50mm x 100mm x 2 layer for $11.50 with soldermask and silkscreen. This is bigger than I need I believe.

I am a long way from wanting PCB's making though...

I have been working on a custom youtube channel for some videos and I should have time this weekend to record a few and edit them up. Just need to get 40 hours logged on a programming job which means doing about 45-50 real hours :eek:

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OP
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Gromett
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I have attempted to make some videos today. I have had a few problems though :(
My phone will record videos fine due to the built in LED light. But once a video file gets to a certain size it crashes.
The new web cam I bought does great videos but is no good at focusing in low light.

I need to add some lighting to my filming area. So my first project is to make a power supply and LED lighting rig for the filming area.

The other issue I have is that the macro focusing on my web cam is not brilliant, but to be fair it is not designed for that. So in early January I will be buying this microscope for filming the close up stuff. http://amzn.to/2iJZQPh

Sorry, for another delay. I now have 5 boxes stuffed with components, modules, sensors, display modules and other electronic fun to get filmed and experiment and play with. I am really looking forward to getting on with this now :)
 

Minxy

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Karl ... stop talking about it all and DO it! :ROFLMAO:
 
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I think that was a very complex project. Did you finish it?
Just rebuilt my 'old school' fan controller, I first made it a couple of years ago, but this one has a couple of improvements (over voltage protection, nicer box and 3mm LEDs:love:)

It just has one temperature sensor that pushes into the condenser fins, (after all the refrigerant doesn't care what the ambient temperature is, just condensing temperature)

It's centred round the legendary 555 chip and a TIP32 transistor, very reliable and doesn't use any power when the fans are off, except the new power on LED (10ma). Costs about a fiver and a couple of hours to make (y)

20190416_153023.jpg
 
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I still like my even 'older school' fridge fan controller......when it's 'ot I plugs it in & when it's not I don't:)

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