Dave, I have another question about protecting the LT3080, which you may have shown now is not necessary, but I was interested to understand it.
Rather than trying to introduce various fat diodes to shunt away any voltage applied back into the output from a charging battery or something similar, could you not introduce a forward-biased diode into the output of the LT3080, before the VSense signal? That way, the diode drop is inside the feedback loop. Would the feedback loop performance suffer? Yes, it loses us 3/4 volt, but that would not bother me...
Dave, I have another question about protecting the LT3080, which you may have shown now is not necessary, but I was interested to understand it.
Rather than trying to introduce various fat diodes to shunt away any voltage applied back into the output from a charging battery or something similar, could you not introduce a forward-biased diode into the output of the LT3080, before the VSense signal? That way, the diode drop is inside the feedback loop. Would the feedback loop performance suffer? Yes, it loses us 3/4 volt, but that would not bother me...
It may be a problem, the only way would be to try it, and I don't really wish to spend even more time doing that and refining this and that, I want to get something out the door before hell freezes over
Dave.
I believe that plain C is much better/beautiful/portable/cleaner/understandable (at least for engineers) than Arduino's "C" version. As far the easy printing you could always play with stdio's FILE stream and use printf.
Alexander.
Hello,
Novice question: Is there any reason this couldn't be done with through hole?
I know Dave wanted this to be done with SMD, but if I wanted to do this with through-hole/protoboard, would there be any special considerations?
Thanks!
(PS sorry if this isn't the appropriate thread... I'm pretty new here)
Novice question: Is there any reason this couldn't be done with through hole?
I know Dave wanted this to be done with SMD, but if I wanted to do this with through-hole/protoboard, would there be any special considerations?
If you had a mosfet on the output to switch the output on/off (quite a handy feature) would you still even have to worry about voltage feedback from the output? If the PSU is powered down and the mosfet gate is tied to ground, no current should flow back into the voltage regulator?
If you had a mosfet on the output to switch the output on/off (quite a handy feature) would you still even have to worry about voltage feedback from the output? If the PSU is powered down and the mosfet gate is tied to ground, no current should flow back into the voltage regulator?
MOSFETs are not ideal for this. Power MOSFETs have a body diode so that under reverse bias they conduct regardless of the gate voltage. A mechanical relay is still the best way to switch something actually off, although an SSR is pretty good as long as you want normally open contacts.
It isn't really a big deal though. The protection diode is only needed if the input can be shorted. If the total design does not have that as a failure mode you don't have to worry about it. If you do decide to care it should be no problem for a builder to wire a 5 amp discrete diode across the entire supply. Keep in mind that this might still damage the "load" that is supplying the fault current.
AFAIK all Arduino compatible Ethernet variants use the Wiznet W5100 chip which is fine pitch SMD.
Hardly suitable for a DIY kit.
Dave.
The microchip ENC28J60 is available in a 28pin DIP package. I'm sure there's an arduino library for it somewhere.
For a micro I was going to go with a PIC18F4550 for a few reasons.
2) Hardware i2c, serial, and USB2.0 (all usable at once I believe)
Another point about the suggested volts/amps range of Dave's original design (which has certainly got us all talking!).
I think the original design, while admittedly stretchable, was going to top out at 10-12V and at 1A... the argument being that nobody needed more than that.
No, it's not designed to be a battery charger. What's the point in that when you can buy intelligent multi-chemisty multi-cell high current balanced battery chargers for $20-$30?