Search found 2 matches

by grendell
Mon Sep 04, 2017 1:36 pm
Forum: Module Discussion
Topic: Using 1N4148 As A Temperature Sensor
Replies: 1
Views: 1709

Re: Using 1N4148 As A Temperature Sensor

Hi there, I could not see your circuit however, any semiconductor forward voltage will change with temperature. If you look at fig 1 of your datasheet for the 1N4148 you will see that at (for example) 1mA the forward voltage is about 0.7v @ 25c but drops to 0.4v @ 125c. This is quite a small change ...
by grendell
Fri Sep 01, 2017 4:42 pm
Forum: EtherMega
Topic: Passive PoE for EtherMega
Replies: 0
Views: 1068

Passive PoE for EtherMega

Hi, I am intending to power the EtherMega from a remote 9v supply using a passive power injector with pins 1&2 and 3&4 of the PoE connector linked . I assume the voltage will be available at the VIN pin (less a diode drop). My question is what is the current rating of the diodes in the RJ45 socket? ...