NEW "Power Supply 12V 2A for CCTV camera" for R33 each, my local electronics store sells "5V, 1A Regulated Power Supply Module (ANY22I)" for R200 and "1.2 - 15V/5A Adjustable Regulated PSU (KIT58S)" for R114.80 both kits. The R114.80 Kit requires you buy your own 9-0-9 transformer that "Transformer 9-0-9 4A (AMZ60G)" goes for R309.26... So I bought 8 of the 12V switch mode power supplies for CCTV camera. My Dad is giving me his old reciever (audio board broken) for TV, and it's got a Toroidal that I'm hoping on!

 

now I'm time travelling to the future, how would I determine the specs of the toroidal, to see if it would deliver? guess my multimeter at a couple of spots

 

The meter is plenty good enough to start with.

What about the 12V power supplies, is my guess correct, are they old wall warts? (That's not a problem)

wat is a wall wart?

 

wat is a wall wart?

Basically the thing you plug in the wall socket to charge your phone.(AC Adapter)

 

wat is a wall wart?

http://en.wikipedia.org/wiki/AC_adapter
Yes but its new wall warts, basically

 

Age doesn't matter as long as electrolytic capacitor and fuse are fine its going to work.

 

Age doesn't matter as long as electrolytic capacitor and fuse are fine its going to work.

only about 3 years old, and I mean what voltage , or rather what specs. Does it matter? some transformers step down to other values than other transformers, if this one is too high (if that's possible) what then?

 

My Dad is giving me his old reciever (audio board broken) for TV

Probably lots of useful power transistors in there.

Not (just) transformers.

Is the R for Rand or Rupees or Riyals?

 

Rand
(Cape Town baby!)

 

So your mains is 220 Volts?

 

yup
The South African electricity supply is 220/230 volts AC 50 HZ.

 

Old radios from 80s have loads of useful linear pots,motors,trough hole components,etc..
You will need to find out power rating of main transformer from audio board after that you can measure the voltage from secondary to get max. current.Power rating should be printed somewhere on the board(close to the power cord).

 

now I'm not trying to make my problem yours, I just ask for advice, these are the heatsinks I can buy at my local store, my far away store might have a bigger range, but I don't really have transport so my further away store is actually not a possibility (mantech.co.za) Here's the heatsinks I can buy: http://www.fort777.co.za/index.php?main_page=index&cPath=715_1066

I looked at a couple and unfortunately they don't give the thermal resistance of any of them. What you would need to do is take the manufacturer/model information and look them up separately somewhere that does give the specs. DigiKey might be sufficient or you might go directly to the manufacturer's websites.

Note that whatever technique you use to get your power, if it is linear (which means that you are not building some time of switching power supply to step down your voltage) you will still have to vent the same amount of power because at 1 A you are still drawing 12 W of power from your supply but only delivering 5 W to you load. You need to dissipate the other 7 W somehow.

 

He could simply buy second hand CPU heatsink and drill M3 sized hole for To220. Those heatsinks are good up to 100W.

 

He could simply buy second hand CPU heatsink and drill M3 sized hole for To220. Those heatsinks are good up to 100W.

Say that a heatsink is good up to 100 W is largely a meaningless statement. A heatsink has a certain power handling capacity when used a specific way and it's capacity can be drastically different when used some other way. CPU heatsinks are designed such that the heat enters them over a large area compared to that available on a TO-220 case, so you can expect the thermal resistance to be considerably higher when mounted on such a case compared to when it is mounted on a compatible CPU. Not saying it won't work -- in fact it probably will at this power level. But this notion that a heat sink that can handle X watts in one application can always handle X watts is wrong and dangerous.

 

CPU heatsink will work fine with TO220 package.Back in the 90's heatsink was mounted pretty much straight on top of the CPU die and they worked fine.CPU die has size of TO220 thermal tab.

 

will this drilling (if I can get the right size bit/ one too small, other too big. my kit just says 1,2,3,4,5,5.5,6 guessing its inches) would it be possible with a hand drill? and I'll send pic of my only old CPU heatsink I've got, just now... my phone camera sucks so I'll see if I can get something usefull.

[COMPLETELY OFF TOPIC, why do we have word completion on our phones but not on our desktops?]

 

What kind of hand drill?Power drill or hand powered?
Those drill bits are probably in mm's one inch is pretty big.

 

the pics aren't that good, but should give an Idea of what I'm working with.

 

Those transistors are MJE3055, thought of using it as driver for buzzer, realized it was over sized for the needs