Resistors or not?

[KTW]

Does anyone know if these light panels have resistors built into them or do they even require them?
Thanks.

 

[Harald Kapp]

Do you have a datasheet or a link?

 

[dorke]

Do you have parts numbers?
Look in the datasheets, there is your answer.

 

[Chemelec]

Resistor, Not Likely it is built in.
Mainly because the resistor will depend on your Supply Voltage.

 

[KTW]

I'll hunt for a data sheet, they are readily available on ebay but they just list the voltage as 12 volts DC.

 

[dorke]

If they are listed as "12V" they need no resistor.

They should be the automotive type,"stealing" 12V from existing 12V sockets in a car,
via the black female connector/adapter inserted instead of a light bulb.
The LED matrix with the male connector is then plugged in the female to supply the 12V to the LEDs.

 

[(*steve*)]

Those panels work fine at 12V at a particular temperature, on a particular day, when the phase of the moon is right.

At other times and in other conditions they will either draw less current (besides being a little dim this is no problem) our more current (which is a problem).

Technically, these LEDs often use excess bulk semiconductor to increase their series resistance. This helps but is no guarantee. They are built to a (very low) price.