I know the circuit is little complex but still will it serve the purpose
Clients servicing items may include motors, circuit boards motors linked with ciruit boards etc. Mostly all are Industrial related it can be of any operating voltage like 12V,9v,5V,6V, etc.
power supply i tryed both circuits which is enclosed
I am using only National Semiconductor LM338K and using it as desktop powersupply, (0-12 volt, 9 amps transformer) vin is 18 volt after bridge rectifier & capacitor and using it for checking all the circuit board which ever am servicing. Seperate toggle switch is provided for + output for connecting and disconnecting the load. Protection diode is also fixed at output terminal.
Majority of time i had noticed is when the + probe and - probe (output of the powersupply) accidently touches eachother the out put is "0" volt on touching the ic the temperature is also normal (cool). at some circumstance it may be difficult to find the amper of the item which is under service, so i'll have to connect to the powersupply if it is with in 5 amps no problem if not........ the output is only "0" volt.