mateck8888 0 Posted October 9, 2013 Hello: I am working on servicing an older CCTV analog system. I came across a camera today that had what looks like your typical 120v to 24v naked doorbell transformer power it. I freaked out when I saw that it had 18 gauge wire on the primaries so I took my volt meter to it, and it turns out it was 24vac. So we have 24VAC on the primary and the secondary. Does anyone know what kind of device this is? It had a part number on it, but no manufacture name on it. Does anyone know what this would be for? 24vac in and 24vac out? Seems strange. Thanks. Matt Share this post Link to post Share on other sites
Horizon 0 Posted October 11, 2013 Hi there. Yes, I've run into one of these isolating transformers in an old Pelco PTZ dome. I reckon they are sometimes used on old equipment to break ground loops, so you can use more than one camera or PTZ on a power supply. These days you get this feature for free by buying cameras that incorporate isolated switch-mode power supplies. Share this post Link to post Share on other sites
mateck8888 0 Posted October 12, 2013 Hey, thanks! That makes sense, because the power line that this camera was running on was feeding a couple of other cameras with transformers, and it was an older camera system. Thanks for solving mystery. Matt Share this post Link to post Share on other sites
mateck8888 0 Posted November 5, 2013 Can't send a photo without going back out... a ways of a drive. But it looks just like your typical doorbell 24VAC transformer. I think "Horizon" was correct in his reply. It turns out there was multiple cameras on one line, with each one having one of these transformers. And the input was 24VAC, and the output was 24VAC, so what he said made sense. Share this post Link to post Share on other sites