Purpose:When many single-battery machines are under heavy loads, for example, if the backlights are switched to the brightest light and 3D games are run, pulling DC power is prone to machine crashes or blurred screens;
Cause:Q5's conduction time is not enough. It is expected to speed up to the conduction time through the fast discharge of G pole;
Circuit before modification:
(Switch when the battery voltage is 3.65v, yellow indicates VB, G pole of green MOS) when running a 3D game, remove the charging power, switch the MOs to the on status takes about 32 ms, VB drop is 725mV.
(Switch when the battery voltage is 970mV V, yellow indicates VB, G pole of green MOS) when running a 3D game, it takes about 11 ms to remove the charging power, the mos tube to turn on the status, VB drop is, system restart.
After modification:
(Switch when the battery voltage is 3.65v, yellow indicates VB, G pole of green MOS.) When running a 3D game, it takes about ms to remove the charging power, VB drop is about 200mV.
(Switching when the battery voltage is V, yellow indicates VB, G pole of green MOS) when running a 3D game, it takes about ms to remove the charging power, and switch the MOs to the on-going status. VB basically does not drop, the system has not been restarted.
Conclusion:From the above experiment, we can see that when the charger is removed, the modified circuit can make the charge of the capacitor of the mos tube clean up faster, and the mos tube can turn on faster. When a single battery is low, the problem caused by removing the charging power can be well solved.
Battery and adapter switching circuit improvement Experiment