Hello, 
I just bought a second hand camera and I'm trying to make sure it works. There is a power input on the back of the camera which is labelled negative, ground and negative in that order. They are the symbols so it reads " - G -". The transformer that it came with is a 24 volt AC output.  
  
I have always assumed the ground was negative, so where then do I connect the positive lead?  
  
Unfortunately, there is no info on the camera to reference. It does have an adjustable lens and it's not a plug and play model (no power cord). 
  
Any help would be appreciated. 
  
Thanks! 
  
Dan