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

Hand Drill, ok mm's then... what do I need to buy, if it's conceivably possible with hand drill

 

the pics aren't that good, but should give an Idea of what I'm working with.View attachment 75625

sorry for the big image in the post, didn't know how the system works, from now on ONLY THUMBNAILS ;-)

 

If by hand drill you mean electrically powered drill then you can.You will need 3mm HSS bit and WD40 or some sort of oil to lubricate the drilling spot.
That heatsink should work fine.

 

Well, the only TO220 I have are the MJE3055, and the 3mm bit has some room to spare around it when I put it through the 3055's hole. Is that intentional, what use would it have? I only know about my neighbour who got all his power tools stolen, so I'm outta luck for now... for now it's hand drill.

the CPU one is
25 x 50 x 50 mm
OR
for R20.45 (easily do-able)
Dims: 25(h) x 34(w) x 12(d)
OR
for R14.52
28(h) x 25(w) x 11(d)mm, 4.1g

So if I can't hand drill it, then I'm stuck with the ready made TO220 heatsinks.

Your opinion: requires more research OR the R20 one will probably do fine. OR find someone with a power drill?

 

Are you thinking of building my emitter follower or something else?

Using the MJE3055 will give us plenty of opportunity to improve you rule of thumb circuit calculation skills.

Do you know what transistor gain is?

 

Those are tiny heatsinks they cant dissipate something like 20W.Those small heatsinks are fine for 2-4W.You are going to need to use that CPU heatsink.Screw doesn't have to be perfect fit as long as its keeping TO220 firmly on the heatsink,you should apply small amount of thermal paste to TO220's thermal tab.

What are you planning on building?
Studiot's PSU or regulator one?

 

hFE MJ3055 is 100. put in 1mA at base get out 100mA at emittor and collector pulls the current from your, well source, the Power P=V*I

I need more info before I could decide between the regulator and the emittor follower your pitching, If I don't need heatsinks, your's will probably win

 

Studiot's example is more educational while regulator one is pretty simple.You are going to need heatsink if you are passing high currents trough the transistor.

 

If you are going to buy a regulator, you might as well buy an LM309K and have done with it.

You won't need the transistor then.

 

As WBahn said, you will need to dissipate the heat somewhere.

You don't however need an 'official' heatsink.
A large chunk of metal can also do pretty well.

But before you start, do the measurements I asked for on your CCTV supplies.
I am interested in isolation between the mains input and the output, for safety reasons.

Also you will not get a gain of 100 at a current of 1 amp or more from the 3055. Perhaps down to 30 by 2 amps.

 

One thing I particularly like about AAC is the way that members can co-operate with each other.

This is far better than any other forum I know, where there is often too much competition or worse.

 

But before you start, do the measurements I asked for on your CCTV supplies.
I am interested in isolation between the mains input and the output, for safety reasons.

Doesn't measure, means its more than 2000K

 

If you are going to buy a regulator, you might as well buy an LM309K and have done with it.

You won't need the transistor then.

www.mantech.co.za not so easy to get there/ transport problems, this isn't the one you had in mind is it?
Stock Code 14M1348-T
Part Number NTE309K
Description REG FIX POS TO3 5V 1A
Manufacturer NTE
Sold In Each
Minimum Order Qty 1.00
Alternate Part Number
Memo 5 VOLT FIXED POSITIVE VOLTAGE REGULATOR
INPUT: 35V (MAX) OUTPUT: 5V @ 1 AMP

The closest to 309K they have

 

When you decide to buy the transistor or regulator I would recommend you to look for ones in TO220 package only.TO3 is really pain in the as* to mount since it requires 4 holes and special thermal pad so you don't short circuit the pins.
You can buy LM350 if you decide to go with regulator solution.

 

A large chunk of metal can also do pretty well..

like the side of a computer casing?

 

Anything made of aluminium will work fine as long as it has big enough size.

 

Anything made of aluminium will work fine as long as it has big enough size.

how would I know?

The holes are EXACLY the same size as those in the 3055, so I guess all TO220 holes will work, and I guess a fan could be added, how much mA does a smallish fan require?

 

Indeed yes a substantial case is often used as a heatsink.
But you must clear off enamel/resin coatings to ensure good thermal contact.

Yes the TO220 case (like your MJE3055 pic) can be easier to fix since it can be single hole, but is less rugged than TO3.
And yes there are more modern ones than the 309 and there are T0220 versions of the 309.

The psu in picture I showed has a 309K mounted on the outside of the back of the case.

The isolation of your 12V supply is good. I said It shouldn't be possible for your meter to measure it ie it goes overrange.

 

Small 80mm fan will draw something like 160mA.

 

Ugh, the holes are too far from the side of the casing for me to use those hole, but with that thickness of the panel, I think a hand drill would do the trick. OH, what about screw thread, how does that work, and what screws do I use.

I'm pretty keen on studiot's solution, studiot the heat needs to go somewhere no matter what method u use, but will your method work with the heatsinks I posted earlier, just more of them?