No More TO-3 Voltage Regulators?

Question

Looking for a replacement LM340K-24 fixed 24V 1A linear regulator for my bench power supply I've dicovered that TO-3 voltage regulators seem to be in the last stages of disappearing entirely.

Looking at all the whole category of TO-3 voltage regulators:

RS only have 4 models, and want around $100 to buy them individually:

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Element 14 have 6 models and mostly similar pricing:

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None are fixed 24v regulators. (Rockby do have some TO-3 regs cheap, but no +24V ones there either).

TI don't list any TO-3 package LM340s being made:

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It looks like the only option might be NOS sellers on Ebay, and there aren't even any of those in Australia...

I guess everyone's using switch-mode regulators for higher power applications now, though I'm still surprised that such a previously common package for a range of still-common components has gone out of production.

Phil Allison · Accepted Answer

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** Nonsense:

WES Components have the LM338K, 5A, 1.2V to 40V reg for $7 or $8+

Best TO3 reg ever made, phenomenal specs.

They also have the L7812CT 1.5A, 12V for about $3 in TO3

Use a 12V zener on the ground pin to get 24V.

Maybe snap a few up.

..... Phil

Computer Nerd Kev · Answer

Hmm, yeah silly me, I forgot about that option. I've got three 7812s in TO-3 package already. --  __          __ #_ < || |< _#

Phil Allison · Answer

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** Good, I like TO3 stuff too but in reality TO220 versions do the same job if dissipation is under 20W or up to 45W for the LM338.

Use thin mica, white grease and clamp the things rather that use the bolt hole for best results.

Just looked at my parts bin and found a variety of TO3 regs :

2 x LM338K 2 x LM317K 1 x LM337K 1 x L7805CT 2 x LT1033

..... Phil

No More TO-3 Voltage Regulators?

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