21-03-2018, 16:05
(21-03-2018, 08:11)engolling Wrote: Hello Werk,
... So I was asking myself why the 7809 is used for battery applications.
The main reason is limiting the power voltage applied to the transmitter module. Specs say that it can be powered to up to 12V, however my experience says that 12V is the maximum allowed and they don't last too much when powered by 12V, by other side the output of most of the cheap solar controllers aren't regulated to 12V and often you can measure 14.8V or more, so not having 7809 regulator will make that the AMS1117 regulator will have to dissipate more power, producing more heat.