Lm317 driver still best cheap option?

[The Lightning Stalker]

Dunno, I always used the TO-3 and assumed the plastic packages are pants. 4x worse heat transfer
according to the datasheet

Anyone care to weigh in? :anyone:

 

[Pi R Squared]

Jameco has them for $1.75 LM338T/NOPB: TEXAS INSTRUMENTS: ICs & Semiconductors and $6.95 for the TO-3 LM338K: MAJOR BRANDS: ICs & Semiconductors

 

[rhd]

Dunno, I always used the TO-3 and assumed the plastic packages are pants.

Why would you heatsink the plastic side ?!?

 

[The Lightning Stalker]

Why would you heatsink the plastic side ?!?

Because there isn't a metal side.

 

[Rifter]

Because there isn't a metal side.

I know the package type you are talking about, it seems like a bad design especially for higher current loads where the metal tab package makes heatsinking much easier. So might as well always go with metal tab package imo.

 

[Cyparagon]

Dunno, I always used the TO-3 and assumed the plastic packages are pants. 4x worse heat transfer
according to the datasheet

TO-3? You sure you don't mean TO-220?

The plastic package is called TO-220FP, and it's used to electrically isolate the case from the heat sink. All materials that are electrically insulative, but thermally conductive... are going to be less thermally conductive than that of an electrically conductive material. But sometimes you need seven ICs bolted to the same heat sink, so they need to be isolated. It's a trade-off.

If you don't need it, don't use it. Doesn't mean it's useless though.

 

[The Lightning Stalker]

Here is the one I've been using (on the right). I hope it doesn't burn out, it's the last one.

This was my first attempt at a small LM1117 driver. It ended up not working out. For some
reason, it needs more capacitance than an LM317 or it will kill diodes. Currently waiting on
some boards, and waiting (what the heck Oshpark?)