Where can I find 78H12, 78H15, 79H12, 79H15? Or something similar?

[Vinnie Lee]

Hi guys and gals! Where can I find these regulators? I've been searching for a week, but can't seem to find any legit source for 78H12, 78H15, 79H12, 79H15. Tried Mouser, no result.

I need some +12V regulators, some -12V regulators, some +15V regulators, and some -15V regulators. And they can handle 5A. I think these kind of things are TO-3.

I found tons of Chinese knockoffs(mainly National Semiconductor), and they can't even handle 1A!
Are they discontinued? If so, what's the substitutions?

Thanks!

 

[shrtrnd]

That's an old one. Did you try eBay?
I see them there.

 

[CapSteel]

LT1084 is a 12V, 5A regulator (check Digikey).

 

[AnalogKid]

Linear Technology and National Semiconductor (now owned by TI) make positive and negative 5 A regulators. Do they have to be fixed, or can you use adjustable parts like the LM338?

ak

 

[Vinnie Lee]

Thanks guys! I ordered some LT1033CT and some LM338T/NOPB.
BTW, what does NOPB mean?

 

[AnalogKid]

Since Pb is the symbol for lead, these probably have a lead-free plating on the leads (NOPB = no lead). Also called RoHS compliant - reduction of hazardous substances (or sonething like that).

ak

 

[Vinnie Lee]

Since Pb is the symbol for lead, these probably have a lead-free plating on the leads (NOPB = no lead). Also called RoHS compliant - reduction of hazardous substances (or sonething like that).

ak

Thanks, AK, that makes sense.

Do you know any linear LDO that can do negative adjustable (around -12V, 3A or higher)? I'm trying to find a negative linear LDO to go with my LD1084V (to build a 2A linear +12V &-12V PSU).

And, if I design my PSU to the 230Vac/+-10% standard (for Europe customers), should I include 207Vac and 253Vac? I mean, that's a wide range.

I could design it as 207Vac, if someone in Europe use my PSU on 250V mains, there'll be more heat. Or, I could go for 230Vac, less heat, but I'm afraid of the increasing ripple and noise when it's used on 210Vac...Also, less output current.

I know that's a lot of questions, but I'm kind of pulling my hair now.
Thanks!