EF: Variable Wattage Box

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Variable Wattage Box

Hi everyone,
I want to make a variable Wattage box. Mainly for testing purposes.
I want some small scale, medium and if possible, some big scale variable wattage ranges.
Lets start with something easy, the small scale. From the back of my mind, I would use a small npn tr like BC548 or BD681 to variate between tens of miliwatt. (Without a Heatsink). For variation of hundreds of mW up to 1W, I remember from my tests, that my 2N3773 was the best choice in this range, again (Without a Heatsink).

• So this is simple, right? The hard part is to switch between a couple of watts, not many, maybe 5W, maybe 10W, Im undecised.
• One important design future is that I want a POT to scale the values, but also in // with it some sort of digital button inc/dec, and the simplest possible I can think of is with a counter IC like my favorite 4017. I was thinking originally on switches but a POT is more elegant.
• I want from you a cct design, an idea, of how you will make it. I already give you half of the solution how I will make it. Im curious how you will do it. Its very important if you already made it in your past, and now its time to shine with its circuit here for me. I love practical solutions, not only the theoretical ones, although Im accommodating any weird ideas that I never tried. See if you can design something quick in your simulator or on paper, or search on the www. Or something that is already consecrated, and you know about it but I don't, will actually be the best, if possible.
• Thank you.

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