Hi all,
My remote MF system is down at the moment, for doing some upgrades and
improvements.
I'm replacing a DC/DC converter which supplies the Raspi with a
constant 5V voltage.
So far i used a LM2596 module, available e.g. at amazon
It was running well with almost no QRM to the RX. It's fixed switching
frequency is at 150 kHz. That's a bit close to LF and the 3rd
harmonic is close to MF! I sometimes saw a weak drifting trace on MF.
Now the new one is a Kis-3r33s module, also available at
amazon. This one is running at 333 kHz, far away from LF and MF,
also it's harmonics.
The main aspect is the efficiency though! I defined a power saving mode
(5V*89mA) and a full power mode (5V*430mA) for the Raspi. Normally the
system runs at full power 24/7.
The LM2596 module has 77.8% efficiency in power saving mode and 78.5%
in full power mode.
The Kis-3r33s module has 83.9% efficiency in power saving mode and 89.9%
in full power mode!
By exchanging this module, is can save 57 mA on the 12V-battery side!!!
:-) This is about 1.4 Ah or 17 Wh per day, which is a LOT for a solar
powered system. So the remote MF system is now consuming 2.4 W
permanently.
Just to share this measurement in case someone of you is running a
similar system.
73, Stefan
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