These last two weeks, I have been bogged down by finals which hasn’t left me much time to work on the new for the next iteration of the TEB. However, I was able to finish the electrical schematic for Rev 2.1, which you can see below. The circuit will be much simpler than the previous iteration as I was able to eliminate many components with this new design. Below are the changes.
- No need to boost the voltage so I got rid of the voltage regulator chip and the accompanying circuitry
- Transistor configuration into a single FET array chip -http://www.diodes.com/datasheets/DMHC3025LSD.pdf
- Smaller Lithium battery will be used, haven’t decided on the form, but am looking at lithium coin cells
- Different battery charging management IC http://ww1.microchip.com/downloads/en/DeviceDoc/22036b.pdf
- Atmel chip microprocessor will be used instead of the whole Sparkfun Pro Micro (have not implemented in schematic yet)
- Battery monitor IC to indicate when battery is low
Note: This is only the first draft. I still need to run a design analysis and check for errors.
