2023-02-16, 12:33
Whilst I agree that decent linear PSU is the way to go to squeeze every last bit of signal out of the noise PoE can be tamed and be very useful if the controler is not within a few feet of mains power, say out in a barn. Sending 0.5 A at 5 V for any distance needs fairly hefty cable to avoid an unacceptable voltage drop.
Switchedmode PSU's do tend to be very noisy but they aren't all created equal. Go trough all those you have and you might find a quiet one. On PoE check out this thread: Blitzortung.org Forum › Public Forums › Hardware, Software, Lightning Physics > PoE recommendations for System Blue (Sep/Oct 2016). That setup has been powering my controller 24/7 for the last seven years with no issues. The mentioned TL-POE10R PoE splitter is still available, at least in the UK, for around GBP 10.00.
The risk of damage to the controler from having 48 V shoved where it shouldn't be is minimal. A proper PoE IEEE 802.3af power source won't provided the full 48 V until it thinks it is connected to a valid powered device. Once up it checks that too much power isn't being drawn and disconnects if there is. Passive PoE, however, is risky, see the mentioned thread above. The biggest risk with the TL-POE10R is the little switch that selects the output voltage to 12, 9 or 5 V being "accidentally" set incorrectly.
Switchedmode PSU's do tend to be very noisy but they aren't all created equal. Go trough all those you have and you might find a quiet one. On PoE check out this thread: Blitzortung.org Forum › Public Forums › Hardware, Software, Lightning Physics > PoE recommendations for System Blue (Sep/Oct 2016). That setup has been powering my controller 24/7 for the last seven years with no issues. The mentioned TL-POE10R PoE splitter is still available, at least in the UK, for around GBP 10.00.
The risk of damage to the controler from having 48 V shoved where it shouldn't be is minimal. A proper PoE IEEE 802.3af power source won't provided the full 48 V until it thinks it is connected to a valid powered device. Once up it checks that too much power isn't being drawn and disconnects if there is. Passive PoE, however, is risky, see the mentioned thread above. The biggest risk with the TL-POE10R is the little switch that selects the output voltage to 12, 9 or 5 V being "accidentally" set incorrectly.