Recent content by mv10

Hmm... and these are the cheapest of the cheap, frankly. I think I paid about $5 each for them, or something like that, and I'm sure even that was a ripoff (but roughly the same as 2 month's worth of D-cells...) I suppose I should try testing them under load, then? Maybe power up the Roomba...

Yeah, 12 new wall-warts is the only real downer here. I already converted the Virtual Walls to AC power and so had bought a pile of 3VDC transformers. But I wouldn't be too surprised if they actually output slightly more (Made In China), so I'll check them as long as I have them here... and...

Cool, I really appreciate all the help and detailed explanations!

Also -- why mAH/20? Where does the 20 come from? (Again, just curious.)

Awesome. I think I have everything I need then. Hmm -- any tips on how to spec out the correct diode? Digikey had a rather vast number of search parameters for diodes...

vk6kro, please define "put a resistor across the diode"... are you saying basically "loop around" the diode with a connection through the resistor? The diode blocks the full current, but the resistor circuit allows a small amount to bypass it? How does one determine what size resistor is...

Actually I did just buy a meter recently which measures mA. (Previously I just had one of those cheapo Radio Shack pocket deals which only did resistance and voltage.) I guess I have to put it inline if I remember correctly, yes? (Sorry for the basic questions...)

Oh yeah -- sorry about that, I hit the wrong button in Visio (looking for h-flip to put the text on the right and accidentally hit v-flip then forgot to flip it back). Am I right in thinking that as long as the forward and reverse voltages are somewhere above my 3V requirement (there are quite...

Thanks for all the suggestions! We have 12 of these, so I'm looking for the simplest possible angle, which makes the diode a great idea if it works. Not looking forward to building 12 copies of anything that involves soldering IC, or making breadboards, etc... They're distributed all over the...

Thanks. Yes, Roombas are the robotic vacs. Sorry, with several bumping around every day, I forget that not everyone may recognize the name. (And the situation is slightly worse, I had forgotten, but these are actually chewing up a pair of D cells per unit, not C cells...) It looks like Schottky...

We have several Roombas in the house and we use a lot (12) of those little "invisible walls" to control where they can and can't go. They're all programmed to daily schedules, but even so, the invisible walls eat up a pair of C-cells every 60 days or so. 24 C-cells every couple of months gets...