I see that they sell POE adapters that would still require a separate power supply. I bought one and it doesn't work with a POE switch.
Trying to avoid the need to add power adapter but simply step down the 48v to 12v from the switch to the Foscam camera.
Not sure of:
1. Do you have a PoE injector or PoE switch and if so what is the output voltage and does it support active or passive PoE.
2. Your distance from the PoE power supply and the camera in feet?
3. What are your cameras DC power requirements? I ask because you don't mention the Foscam IP Camera model.
Do you mean something like this? http://www.amazon.com/dp/B00SM196AE
Which for Foscam IP Cameras can be 5V or 12V DC. The prior post quoted above. Shows a IEEE 802.3af compliant active PoE splitter that can only support 12V DC output.
Whereas the ones below are IEEE 802.3af compliant and use Active PoE and support 5V and 12V DC by simply using a switch on the Active PoE splitter selecting the voltage to deliver to the camera.
Active PoE will also get you greater distances and better IP Camera stability than passive PoE can with the dynamic loads that IP Cameras can have such as IP Camera startup and when PTZ motors are in use and/or IR lights are on.
Foscam suggests to use IEEE 802.3af compliant Active PoE equipment with any/all of their IP Camera models that do not natively support PoE. Because changes in loads ("IP Camera startup, using PTZ motors and/or IR lights going on") can cause IP Camera instability issues, without Active PoE and using IEEE 802.3af compliant PoE equipment when the Foscam IP Camera model does not natively support PoE.
Foscam offers Active PoE Injectors/Splitters sold as a pair or separately:http://foscam.us/accessories.html/
Note: It's never a good idea to use passive PoE with IP Cameras of any brand and model that don't natively support PoE. Because they have such a wide possible range of current usage. IP Camera startup, PTZ motors and IR lights.
Unless the distance from the injector/switch is less than 100 feet and the IP Cameras voltage requirement is 12V DC without active PoE and a splitter. If the IP Camera voltage requirement was 5V DC then it's never a good idea to go over a distance of 10 feet without active PoE and a splitter.