PIR light circuit

[KTW]

Hello, I'm building a 12 volt 48LED light panel circuit that will operate off a PIR sensor with a 9 volt DC power supply.
There will be a LDR built into the circuit so the light stays off during the day.
I'll have a npn transistor within the circuit so I'm trying to determine the value and placement of resistors.
Considering the light panel is designed to operate directly from 12 volts DC I shouldn't need a resistor in front of it but I think I may require a resistor to protect the transistor, just not sure what value.
I may also add a variable resistor to control the LDR.
Thanks for any advice you can offer.

 

[duke37]

The LDR should not be in series with the LEDs, this should be replaced by a current control resistor. A base resistor should be added to control the base current. More information on the panel and LED assembly would help.

 

[KTW]

Thanks Duke.
The LED panel is like this one
http://www.ebay.com/itm/48-SMD-3528...Parts_Accessories&hash=item4857cf2722&vxp=mtr

These are designed for 12 volt automotive use and I found where someone had placed a value of 230mA on them.
The LDR is necessary for the circuit to work on it's own during the night.
I have a similar circuit built and it's working but I want to add the photoresistor.
I don't have any resistors on this circuit but I know there should be one or more.

I was looking at this also as an option.