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Member Since: July 9, 2010

Country: United States

  • Correct me if I’m wrong, but the Aoyue 850A has no digital readout.

  • can you tell me what the internal resistance of this battery is? (let’s say for short pulses, < 0.1 second)

  • My measurements on Sparkfun NCP1400 5V out 100 mA circuit (3.2V in, resistive load) efficiency vs current out: 81% @ 25 mA, 67% @ 50 mA. noise on 5V, 50 mA out: 34mVrms, 300 mVpp (20 MHz BW) 40 mVrms, 600 mVpp (100 MHz BW). With 5 V, 25 mA out: 18mVrms, 230 mVpp (20 MHz BW), 28 mVrms, 400 mVpp (100 MHz BW).
    Current draw from 3.34V with no load: 1.2 mA
    Comparing Pololu #798 (uses NCP1402, 5V out, up to 200 mA with >2.7V in). Measured at 3.2V input, resistive load: efficiency vs. current out: 81% @4 mA, 84% @25 mA, 86% @50 mA. noise on 5V out: 10 mVrms, 50 mVpp in 20 MHz BW and 14 mVrms, 100 mVpp in 100 MHz BW (independent of load current, over tested load range)
    ripple frequency variable, increases with load current: 5 kHz @ 4ma, 50 kHz @ 50 mA output. Vout: 5.004 V to 5.010 V (Vout increases with higher load). (2nd unit tested, Vout= 4.98 V.) Current draw from 3.3V source with no load: 200 uA
    Pololu is 2x max current, cheaper, smaller, lower noise, and more efficient at every load.

  • Still don’t understood why some see such a negative in “easy to use and hides lots of messy time-consuming details.” In many cases, that’s what you want. It’s just another option and I like options. I’ve done embedded development on many different systems for about 20 years, it is part of my day job. Still takes me time to start up with a new system, so I really like the Arduino when I just want to get something done. Plus the price, I would love to see a FPGA dev system anywhere near as cheap! (although, I see knjn.com has some under $100)

  • Kester’s 2331-ZX data sheet says cleaning is recommended, as below. So are people actually washing their boards with DI water at 140 F ? Just curious.
    “…It is not recommended to use high mineral content tap water. Otherwise, tap, deionized or softened water may be used for cleaning. The optimum water temperature is 54-66?C (130-150?F), although lower temperatures may be sufficient.”

  • In case anyone wonders about the size, my sample is 18.25 mm x 33.32 mm x 2.60 mm. The tallest parts are two caps, then the button. If you removed the caps and the reset button, the height would be 2.03 mm (due to the CPU). The PCB itself is 0.94 mm (37 mils) thick.

No public wish lists :(