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  1. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    Hi LiteYear, Yes we considered just monitoring the output voltage, but here was the issue with that: There is overlap because battery voltage could be anywhere between 3.2V and 4.2V at any point in time. Charging voltage could also be anywhere in the same range as well, because most charging...
  2. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    Hi LiteYear, Yes I do just need to detect which voltage is greater, but the problem as I understand it is that the point at which I can measure the charger voltage is the same as the output of the booster. So they are one and the same unless I create a little voltage drop between the two using...
  3. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    Liteyear: Below is the typical application circuit, which is what we would be using. I guess a big question is: What happens when a charging voltage is applied at the output side and can that even be detected? My guess at the moment is that the charge IC (we do not have access to the datasheet...
  4. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    Hi Scotty, Unfortunately I don't think the diode will work on the discharge path due to needing every tenth of a volt we can get to get all the power out of the battery. On the charge path, the float voltage must be controlled very precisely on Li-Ion cells, so it won't work there either.
  5. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    It is true that the trickle charge is just based on float voltage. We don't actually care about the values of the current being detected though, just the polarity (direction). I.e., we just need to know that it is charging so that we can bypass the boost converter. If we have ANY current going...
  6. wingneckedhorse

    sensing tiny and huge current without dropping too much power

    I am having a bit of a conundrum trying to come up with a current detection scheme for a battery and power circuit. There is a boost IC between the LiIon battery and a load. We need to sense when a charging voltage/current has been applied at the output of the boost (battery charge is coming...
  7. wingneckedhorse

    a newbie question about soldering station

    MacGuyver, are you thinking of OKI solder stations by chance? They own Metcal now it seems, which was always a popular brand with techs.
  8. wingneckedhorse

    decipher this german circuit

    Got it now. Thanks!
  9. wingneckedhorse

    decipher this german circuit

    Ah ok. Thanks. How would it buffer the voltage value of the resistor divider across to the output? I can't visualize how that would happen unless the FETs were operating in their linear regions, but that would be no good for a power source, no? To me, it looks like either the top rail being...
  10. wingneckedhorse

    Soldering millimeter components (Cree LEDs)

    We work with the same Cree LEDs and it is very difficult to solder to the leads. Why not use regular axial (leaded) LEDs until you are through with prototyping? There are lots of tricolor and white LEDs out there in larger packages and you could get close enough by matching wavelengths. If you...
  11. wingneckedhorse

    decipher this german circuit

    http://patentscope.wipo.int/search/en/WO2006015713 What does the circuit in the above link do? We've been asked by a client to look into using this to combine power sources with different voltages into a "halfway voltage" power supply. E.g. Input 5V and 3V supply and out the other side comes a...

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