Fixed V-Reg into Vairable V-reg

[Overclocked]

Ive read on the net that its possible to make a fixed V-reg into a Vairable V-reg by adding a pot. Is this true? Has anyone ever tried it and can confirm it works? Ive lost the link to the site though.

Reason being, I need a very low drop out regulator thats adjustable and can supply around 1A but, Most very low drop out V-regs are SMD. I dont think its a problem, but Im still using the ink and pen method. It would be a nice challenge though to get a SMD/through PCB working though from the ink and pen method..

 

[justDIY]

check your datasheets

looking in at the common LM7805, there are several examples for making it into adjustable voltage, involving an op-amp and a pot

but thats kinda the backwards way to do something... buy fixed and turn it into adjustable, doesn't make sense for a new design

check out National Semiconductor's LDO linear regs or their "Simple Switchers", there's plenty of options for adjustable