One of the things I don’t have with me is a junk drawer of electronics parts that a lot of hobbyists seem to have accumulated over time.
Sure, I recently (past couple of months) ordered some collection of resistors, caps, transistors, diodes, and such from eBay — all from China of course. These are the main set of components — not all passives I suppose, but the simple stuff out of which get built bigger stuff.
The problem is I don’t have the main set of jellybean components in my drawer. Things like the 555, or some op amps or other 74-series logic. It’s things that you need when putting together a circuit so you don’t have to stop every moment to either run out to a store or worse yet, order something and wait another week for the next stop of the project at hand.
Of course I also have an immediate need for some prototype parts for my USB charger anyway. I’ll need the I2C I/O expander, the ADCs, the charge controller, and current-sense amps… along with boards to mount them to as well since these are all surface-mount components. I can get some of these from free from the manufacturers, but some I’ll have to shell out some $$ for. I’ll even try to lay out a proto board or something for all of these chips so I don’t have to get remade stuff.
Oh… and some load resistors. You don’t have a bunch of 5 and 10W resistors of specific values in most junk boxes…
Stuff and parts… parts and stuff…
At least the design of the charger has been pretty much stable for a while now. It’s looking like things will weigh in at around $3.00 or so per port in small quantities. A 64-port charger for around $200 not counting the power supply $200) is quite competitive compared to the low end ones I’ve seen for $600+.
And of course I think mine is better. :-P