quote: For a given amount of 10kHz rejection, a 1ksps ADC (a) is equivalent to a 1Msps SAR ADC (b). Filtering determines the ADC's effective throughput, not the sampling rate (c).
exactly! (click to see full res version. from an excellent article, "Managing high-voltage lithium-ion batteries in HEVs" by Michael Kultgen.
more notes:
- gasoline holds 80 times the energy per mass as lithium ion batteries.
- the peak efficiency of the internal combustion engine, however, is only 30% (I remember a figure of more like 20% for carnot cycle .. maybe this is for the Atkinson cycle), and 12% at RPM.
- Cell balancing is a critical feature in series battery packs in e.g. HEVs. if a weak cell receives the same number of coulombs during charge and discharge as a strong cell, then that cell uses more of its available capacity, and hence becomes weaker.
- HEVs (prius) use passive balancing - they discharge the higher-capacity cells to match that of the lower capacity cells. Not efficient, but it prolongs the life of the pack.
- More expensive EVs use active balancing, where capacitors are switched between cells to redistribute charge.
- an electric bus costs about $480,000 !!
other stuff in that issue:
- when interfacing an external chip to a FPGA, make sure all line transitions are registered with the internal clock before fanning out to other registered logic. Otherwise, the flip-flops may not all register the same signal.
- you can design a LED boost converter to run off a single alkaline cell (or lithium cell..) with a PNP & NPN transistor in positive feedback topology.
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