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Mikkel J

Member Since: June 21, 2011

Country: Denmark

  • It needs 5v 1A, so you find a powersupply that will supply that, and enough for the arduino. If you decide to use a 9v powersupply, you go get an LM7805 with good cooling (4W of heat is A LOT). Alternatively, you get a better chip, that can do the 9v->5v conversion more efficiently.

    Alternatively, and what I would recommend, you get a 5v 2A power supply, feed the arduino 5v on any 5v pin in the header, and feed the solenoid 5v directly from the power supply. then control the solenoid with either a relay or a transistor.

  • COMPUTER-PERIPHERAL-POWER-RA in SparkFun-Connectors :)

  • COMPUTER-PERIPHERAL-POWER-RA in SparkFun-Connectors :)

  • If you take a look at the datasheet it will mention that charging is limited to 100mA if connected to a USB supply, and 280mA when power is applied to the DC pin. I do not know where Dirk got the 350mA limit from.

    Concerning drawing current while charging. I do not know if this is possible, but the typical application does seem to suggest that this is possible, as the schematic notes “To system load” and not “To battery”, tho I too seem to remember that there might be some issues with that. With system load they could of course mean the load of the chargin chip, being the battery, however that would be quite silly labeling.

  • The chip does indeed turn off the charging voltage off at ~4v or when the charge current drops below 50mA if memory serves me right

  • As these batteries are just simple LiPo batteries, any LiPo charger will do. Sparkfun sells many of these:

    They’ve been selling these for quite a while now.

  • anyhow, it’s a straight line of pins, Wouldn’t matter too much if you just flipped the part itself during assembly ;)

  • They make that quite obvious, it’s a regulare FET, just the Gate Threshold Voltage is very low (2.5v max) They should probably be classified ultra logic level, as i belive logic level has a Vgs(th) of 4v.

  • There’s no charge pump in these, the Vgs(th) is just very low. To see more accurately “how on” the fets are, check the graph in the datasheet, showing Vgs and current flow

  • What about looking at it from another angle? Maybe start stocking 230v -> 110v 75W transformers, and then make a bundle thingie?

No public wish lists :(