Saber Hand Wind Audio Player - Maintenance Guide
3.1.4 Power management circuit
Technical information
The internal battery charging system is very efficient. For external DC input. The player detects
maximum voltage, change in voltage, change in temperature, and total duration to optimally charge
the battery. The Saber player's red light slowly flashes 4 times before starting to charge the battery
when external DC power is supplied.
The hand-wind generator provides the maximum amount of charge by using a separate maximum
voltage detection circuit, which means that every time the crank handle is turned, the maximum
amount of power is transferred into the player.
Do not make changes to the way the player charges the internal battery. If there is a problem
identified with this circuit, please replace the circuit board.
What happens when low voltage occurs: The reduced volume effect
The player's main amplifier is used to produce high volume levels. At these high levels, the power
draw is large, and causes small spikes which can momentarily drop the supply voltage. When the
internal battery is nearly flat, these spikes can stop the audio chip from working. As a precaution at
low battery levels the volume automatically reduces to 60% to provide protection against these
spikes, with the side effect of slightly extending playback time.
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