Help me design a lipo charger with light switch

Discussion in 'The Projects Forum' started by hyperscorpic, Oct 26, 2013.

  1. hyperscorpic

    Thread Starter New Member

    Oct 26, 2013
    Hi, I need help designing a simple circuit, as I don't have much experience with electronics and circuits.

    I'm trying to come up with a simple circuit that charges a single cell lipo, and also functions as a shake/tilt switch to power a LED. So in essence, when the user shakes/tilt the circuit board, the LED will be powered for about 10 seconds (anything time around that range is good) before tuning off. What I'm aiming for, is something that is relatively easy to make (low parts count) but still safe (i.e. the shake function will not work when the lipo is charging, and automatic cutoff once the lipo is charged etc).

    Here are the specs for the lipo and LEDs...
    Input power will be from a usb port
    Lipo capacity is 70mA to 240mA, so a charge rate of 150mA thereabouts is good. It doesn't have to be a CCCV charging method. A CC charge with 4.1v termination is alright with me (for example), so long as the parts count is low
    LED requires 3.0v, 20mA

    Let me know if you masters need any additional info, and hope you can shine some light on the circuit diagram! Thanks in advance!