Connect it the way schematic says,don't relay on autoroute.

 

Connect it the way schematic says,don't relay on autoroute.

Autoroute does nothing the way the schematic is at the moment, it's when I flip the diode that it freaks out

If the rule holds that square is positive and circle is negative, the diode should be flipped, THAT's where my puzzlement lies. Flip the diode and the otherwise harmonic auto route freaks out.

And I will trust the scematic, not the auto route, question is WHY auto route does what it does... technically the schematic is wrong, square should be at the bottom not the top, but with square at the top auto route says your drawing is correct, which it isn't except if the square means line on diode and not positive

 

Probably a bug or bad routing tool.

 

Probably a bug or bad routing tool.

I'll accept that, my drawing, auto route, completely cut out all the resistors, just ignored them... so auto route (WE KNOW) is buggy

 

are there any setting of VR that would make the regulator burn hot? I have 6 of http://www.fort777.co.za/index.php?main_page=product_info&cPath=715_1066&products_id=9889 guessed though less expensive than http://www.fort777.co.za/index.php?main_page=product_info&cPath=715_1066&products_id=9886 is the better heatsink, if I was wrong, well, faults are schoolfeees. but no heat paste... still looking for a deal!
I can multimeter the 47k, get it at sane rating, let me guess: 3K?

 

Is the circuit working?Are you getting voltage at Vo?Regulator shouldn't be getting hot since its switching reg. and you aren't using all the current .

 

I'm almost done, almost too scared to put the finishing touch, the Vo wires, I've been busy for quite a while so I'm building up courage with a (tabacco) pipe (or 2) before I connect and test. Heated desoldering pump works well!

that's why asked the question about pot, anything to not finish it (immediately)

well I'm putting on the heatsink anyway, anything to postpone testing

OK I promise no not postpone it much longer, wanna re use the wires so its 10min for the desoldering pump, from now (23h00), desolder output terminals, solder output terminals, and then I'll test.

Was it wrong of me to reuse the possibly too overheated IC? I'm pretty sure it didn't go up to 150 'C that would have been a burn and not a "if I put my finger there any longer it would have been a burn"

 

It WORKS! had it at 7.5v 3k output 5.03V, 12v, 3k output 5.03V Now going to wire up one of my cctv psu; that's the test!

 

Good job!Hopefully you learned some stuff and gained some more love towards electronics.

 

All thanks to you ISB123, you rule, helped me at every step! 5.03/5.02V is that close enough for 5V digital circuitry? BTW with the CCTV I get unloaded 13.8V that ossilates with 11.somethingV when I introduce load It'll max out where? roughly. (the CCTV itself unloaded is 14.8V)

This is a big event for me, it's the 4th veroboard I've built and the first one that works! Almost couldn't believe my eyes when I saw 5.03V on the multimeter

 

5.1-4.9V should be fine for digital electronics.Does that CCTV have built in regulator?From my experience voltage drop should be minimal maybe 0.5V if something current heavy is loaded at first then it should stabilize.As long as it supplies 12V under load then its OK.

 

I'm assured that it does, I mean the CCTV camera just won't work if its not 12VDC

couple of questions:
1. does this PSU draw power when idle (no load)?
2. how would a 0.1W trimmer last if you asked for 1W resistors
3. is the Amperage a function of the source Current or Power (Volts times Current)
4. will a lower voltage on the trimmer have a higher amperage?

PS I've got all the components to build every other PSU in this thread and 2 more of the switching ones
LM350, LM7805, MJE3055/MJE2955 (Except for the heat paste and the heatsinks)

PPS reason is transport, I never know when I'll get my next lift

 

what would happen to the heat if we make the emitter follower with 4 stages? thats 8 transistors dissapating the same heat as 1 (the one would probaly be the LM350 or LM7805). cutting the heat by 8... would the small heatsinks work?

 

I'm assured that it does, I mean the CCTV camera just won't work if its not 12VDC

couple of questions:
1. does this PSU draw power when idle (no load)?
2. how would a 0.1W trimmer last if you asked for 1W resistors
3. is the Amperage a function of the source Current or Power (Volts times Current)
4. will a lower voltage on the trimmer have a higher amperage?

PS I've got all the components to build every other PSU in this thread and 2 more of the switching ones
LM350, LM7805, MJE3055/MJE2955 (Except for the heat paste and the heatsinks)

PPS reason is transport, I never know when I'll get my next lift

1.It doesn't I believe it draws only current it needs to stay on without load.
2.It will last for a very long time current trough the voltage divider(R1,R2) is very small.
3.I don't really understand what you mean so I'm just going to say this.
Voltage is "force" which drives the current,increasing the voltage increases the current but increasing the resistance means less current.
Current is directly proportional to voltage but inversely proportional to the resistance.
If you have 5V and 1Ω current will be 5A but if you got 5V and 5Ω current will be 1A.
Power:
P=VxI
4.Depends on the resistance of trimmer and its wiper position.Low voltage can create high current if resistance is low enough.

Using transistors in parallel will spread the current but that doesn't mean that they wont get hot,they will still require a big heatsink. Voltage regulator will require a heatsink too smaller than before but still medium to small heatsink.The resistor will have to be high power one.

 

Upto wat voltage will a 47k trimmer get me? If I have a 20V PSU

 

Should get you up to 50-60V max. but I would recommend smaller pot like 20K-25K since large value single turn pots will have less accuracy than smaller one when working at 20V max. .

 

and if I go and buy specific one for my 12v project, what would I buy? (Desoldering is easy now with my heated vacuum pump) Please what's the calculations or where do I find them? I have trouble with fine tuning at 5v

http://appnote.avrportal.com/calculator/lm2575
V

9.594VR1

1,000Ω R2

6,800Ω

So 10K would work!

 

For high precision you would need 10k multiturn pot if you cant get it buy 10K linear pot which should be pretty accurate.

 

can get it, but dunno about multi turn

 

how would one calculate watt through R1?