Also, as I do have several salvaged aluminium heatsinks salvaged from some components that can be fitted to LM7805, can I use those insted of attaching it to the case?.

Yes, as long as the're big enough to handle the power.

 

I do know I have a 24V transformer

If you can buy an LT3081 regulator, you can make a simple power supply with a maximum output of about 30V, with both current and voltage adjustable to zero.
It also has temperature and current monitor outputs.

The circuit is documented here.

Note that for the higher input voltage from a 24V transformer, the regulator will need to be on a good heat sink. The power dissipated in the regulator will be (Vin-Vout) / Iout.

Schematic and simulation shown below:
It can be modified to give a higher output voltage by increasing the value of R2 and/or U4. Removing R2 will give a maximum output of 25V.
The output voltage equals 50μA * R(U4)||R2.

 

Looks great!
However, I was only able to find IC regulators you can see in screenshot attached below. As it does seems to be quite interesting (maybe even too challenging for me at his point) project, I'll definitely save this for some future time and maybe even order one LT3081 now so I have it ready...

 

Do you have any 3-terminal regulators that look like this?

 

Hello,

The regulator shown by @MrChips is in a TO220 housing.
The older can also be in TO3 metal can housings:
https://www.google.nl/search?tbm=is...0k1j0i5i30k1j0i19k1j0i5i30i19k1.0.hK6IOX2C1do

Bertus

 

If you mean at home, then, yes, I do have some components, but I don't know what used could they be as most of them are Schottky rectifying diodes.
Here's what I have:
S15D40C
D13007K 2 pcs
S20C40C P52C
S20C40C M58E
F12C20C A9D
CTB24L
FMX225 3pcs

And I do have a 2N60B N Channel Mosfet.

 

The power dissipated in the regulator will be (Vin-Vout) / Iout.

Shouldn't that be voltage times current, not voltage divided by current? So:

power = (Vin-Vout) * Iout

 

Shouldn't that be voltage times current, not voltage divided by current? So:

power = (Vin-Vout) * Iout

Duh, of course.
What was I thinking.

 

Hello everyone,
Just an update, I managed to get some more components:
LM7805
LM317T
LM337T
I got the housing and a fast 315mA fuse.
I was unable to get those capacitors and resistors though as I was in a hurry, but I do plan to pick them up in a day or two.

 

Hello everyone!
I don't know if anyone is still watching this thread, but I wanted to post an update.
Few moths ago, I ordered some components from GearBest. I ordered a Arduino Mega Kit with some components such as potentiometers, resistors, LED's... Also, I found this cheap DIY circuit board kit that should be able to take 24VAC and spit out adjustable 0-30V; 0,20-3A DC current. Since it was months since I ordered it, I already gave up on that, but then, few days ago, postman delivered it.
Here's a link to it:
https://www.gearbest.com/diy-parts-components/pp_667690.html
After some soldering (first few solder joints looked like some 3 yo kid took a soldering iron and tried to solder, but later on I really did a good job), and after I got some parts that were missing in the kit (ie I got two 270K resistor but only one was needed on the board, but I got only 2 27K resistors and 3 were needed on the board), I managed to put the board together. Also, there was only one heatsink provided, but I thought that at least 3 components would benefit from having one, the LM7824 regulator used for powering the fan, 2SD1047 and 2SD882. I had some old heatsinks laying around and after some modifications I mounted them on. I will take few photos and post them here when I get back home.
I also found this article about this circuit here:
http://www.qsl.net/z33t/dc_0-30v_0-3A_eng.html
I do have some struggling though:
- If I power this up with a 220VAC- 24VAC 2.5A transformer, how will this LM7824 regulator have enough voltage to operate...?
- There's a 100K trimmer on the board that I suppose is used to adjust max current? I should set it somehow to output max 2A to leave a safety margin?
- I'm just about to go and buy a 10 turn 10K pot for voltage. I suppose there's no point in getting a multiturn pot for current limiting since it's only 0.2-2A?
- I will put a fuse on the live wire before it gets in the transformer, what value should i put there? Fast or slow?
- And finally... And please don't hate me because of this... I have two 12VDC fans. One is rated at 0,16A and the other one is rated at 0.5A. Can I put those two in series and power both from that regulated 24V fan output?

I also have to build an enclosure for it and I will post some photos and maybe some more description as I do it...
Thanks again!