Well I'll be damned.
Testing leds with no current limit??
And what's the deal with D2 on the output after the feedback sensing divider?
No isolation, and less than 5V limit (which will drop significantly with the cable) doesn't make it very capable IMO.
Dave.
Yeah that's what I saw too. No current set/limit/readback, no isolation, and only 5V out, max... if that.
I've seen USB ports actually put out 4.8V, so they might have a 0-4.5V variable supply with a readout. Whoopee!
The writeup talks about charging batteries, so I assume D2 is to protect it in case someone leaves a fully charged
battery connected and pulls the USB power connector. They can't put the voltage sense after the diode because then it would feed back
into the (unpowered) regulator. But I don't think it would harm it. With the diode there as they've done it, they would have
to account for the (unknown) diode voltage drop in their micro. But now the accuracy has all gone to shit.
Nice to see them using a Renesas R8C/2K. I like any design bold enough to break away from the AVR's, and PIC's.
However, for all that they are doing with the micro (just an ADC to provide a voltmeter), a PIC might have been cheaper.
I don't see the value of that supply.