Thank you for all the help, i'm probably going to have to go over your theory a couple of times to see what is going on, as i said my maths is quite poor, ohms law not to much trouble, but multiple equations i find really tuff. I did try another transistor i have the MJH11021G PNP Darlington but it also showed exactly the same as the TIP147 output of almost twice the voltage.
Its well worth wrestling with learning the
LTspice simulator. Its Free (unless you are in the semiconductor manufacturing business), and its professional grade as Linear Technology and their successor Analog Devices use it extensively in-house. The UI can be a little clunky and it doesn't have dumbed down animations and on-screen 'multimeters' etc. - if you want that with a pro-grade simulation engine, expect your wallet to rapidly go on a crash diet!
Once you've got the hang of LTspice, it does nearly all the circuit maths for you. and spits out the results as voltages, currents, power dissipations etc. available at a mouse click, + pretty graphs - waveforms with respect to time or curves to represent sweeping a parameter value as I did above for load current. You rarely have to do anything more complex than back-of-an-envelope Ohms Law calculations to choose a resistor to start with, or maybe calculate a RC time constant to help you choose a capacitor.
Now back to the excess output voltage question - any regulator can deliver too much voltage if you don't meet its minimum load current requirement. Lets look at the Fairchild
LM78xx series datasheet. It says in the LM7812 table on page 8 parameter 'regload' (Load Regulation) is specified from 5mA to 1,5A as typ. 11mV, max. 240mV. The mV numbers aren't important but that 5mA lower limit of the specified range *IS*. Below that load current all bets are off. That's why I included R6 the 2K2 resistor in my design. Its got nom. 12V across it so it draws just under 5.5mA, to satisfy the minimum load current and have a bit left over to mop up leakage current through the pass transistors. Decreasing it to 1K to draw 12mA would help if they are notably leaky when hot. Its also a good place to add a LED power on indicator, as long as you reduce the resistor to allow for the LED voltage drop.
On the same page we can see the max quiescent current is 6mA. That + the R6 min. load current must come through the regulator's input pin and R3 has the job of keeping the pass transistors Vbe low enough so they don't turn on significantly with no load on the circuit's output.
Setting up a quick test jig in LTspice, to bias a transistor using the OnSemi TIP147 model
[TIP147 datasheet] I provided with a voltage swept from 0 to 1V and measuring its collector current, with the effective temperature set to 150 deg C (Tj_max) leads to the conclusion we *ABSOLUTELY* *CANNOT* tolerate 1V Vbe at min.load current when hot as the pass transistors would leak 14mA each and that 2K2 resistor has only got 0.5mA to spare after meeting the LM7812 minimum load requirement.
You could do a similar experiment on your bench with a 1.5V battery (use an alkaline AA, not a lower capacity battery, so the voltage holds up for the duration of the test) and a 1K pot across it to provide the base bias. Hint: include a suitable resistor in series with the transistor collector so you don't pop your multimeter's low current range fuse if you turn up the base voltage too high! Also its going to be more of a PITA in real life heating the transistor close to Tj_max - you'll have to put it on a heatsink with a thermocouple temperature probe with a smear of thermal paste in a close-fitting drilled hole right next to it and heat the finned side of the assembly with a hot air gun as close as you dare to Tj_max.
Back to the LTspice results. Double clicking the curve title (labelled 'Ix(Q1:C)') and sliding the resulting cursor around tells me the leakage current becomes excessive (over the 0.25mA per transistor we can tolerate) with 420mV Vbe. The voltage across R3 will exceed that with only 4.2mA through it which means I've FUBARed the design in my previous post - if you switch off the load when the transistors are hot the output voltage will climb uncontrollably, and trip your crowbar. The fix is to decrease R3. It needs to pass 11.5mA without exceeding 420mV across it. Ohms Law says it cant be over 36.5 Ohms. That would initially lead you to a 33 ohm resistor, but so far this is just a sim-w@nk and I'd be happier with 15 ohms for a much greater safety margin in real life, as the pass transistors h
FE may be significantly greater than the 10K typical value the model uses, or its internal base pulldown resistors may be higher in value.
TIP147 test jig sim attached.