1, linear charge: a pure resistive current limiting is used in buck or charging chip buck, directly below the battery input voltage of 5V voltage required, through the comparison of the internal transistor amplifier or chip for limiting amplifier. Has the advantage of shorter development time cycle success rate is quite high.
Disadvantage 1): this line is linear constant-current to burn off excess energy to achieve blood pressure purpose charge, high temperature and charging current are not big, since charging current, the greater your energy consumption will grow the same cooling surface
Volume also increased.
Drawback 2): the charging battery easily polarized, polarized area becomes larger the more charging current capacity becomes lower, longer battery becomes volume. Best way to reduce the polarization is rechargeable battery runs out, reducing the number of batteries is to lengthen the battery life (polarization refers to the accumulation of oxides hinder electronic movement). Linear charge usually constant current-constant voltage-trickle up three-stage process.
2, pulse charging: a using a CMOS electronic switches, by time and frequency control switch step-down, constant-current charging charge also called PWM control. Control process requires CPU port detection to data for calculation of feedback control adjust the PWM width or frequency through the charging process, the disadvantage is that this circuit technology is quite complex. Pulse charging Po typically has slow constant current-constant voltage charging constant-current fast-charge-trickle fixed four-stage process.