2022-12-03: Curiosity is always good. At least that's what I've been told. Course in this case it was more ignorance and a simple question: 'What is the difference between the Westek 6503BC and 6503HBLC?' It was fairly obvious that the customer wasn't impressed when I flipped over the package and said 'the 6503HBLC is rated for 300 watts while the 6503BC is rated for 150 watts.' It was after he left, buying neither, that I remembered I had one of each at my worktable that had been opened for pictures... So, I'll just say curiosity made me do this...It sounds better that way!
Front View of both Units; 6503BC (6503) is on left and 6503HBLC (6503H) is on the right. I'll try to keep it consistent from here on!
Back View... Not really anything to see here.
Top view with front cover. I can finally spot a difference. The 300 watt version has a heatsink.
Let's take the circuit boards out and bend the triacs out of the way. I'm not really seeing ANYTHING else different...am I missing something?
U1 is marked as TT6061A. Here's a datasheet. (PDF, 5 Pages, 148kB) Page 3 has the recommended circuit diagram, which looks rather familiar.
Back View of circuit board: look identical to me. No components back here and circuit board model is the same.
hmm. Well maybe they just put a higher amperage triac in and added a heatsink... (6503BC shown) Here's a NXP branded BT137-600E Triac (Datasheet, PDF, 14 Pages, 194kB) Datasheet says we have 8 amps of current capacity (RMS).
Then again, maybe not! This is a BT137-600E too. (6503HBLC shown)
We're stuck with a simple conclusion: the only difference between the two is a heatsink. And that makes 150 watts of difference and doesn't seem to change the price. There you go - you now know another mostly useless fact. Hoping that customer comes back in - I've finally got an answer that might satisfy him. Course, he might just shake his head and ask 'Why do you stock both?' to which I now have no answer... Sigh. I can't answer every question with a good satisfying answer.