LED driver barely lights 12V strip

You don't mention a capacitor, a key element in allowing the CL2 to actually function properly.  Also, you're putting 9 volts on it, that gets dropped by around a volt by the CL2, and 8 volts will barely light a 12V LED strip.

Try this, it'll work much better.  18VAC on the input.

Thanks for the reply John

It's for DCC HO passenger cars.  I put a 470 uF 25V Cap across the bridge it and it wouldn't light with the 9V battery at all.

With that same cap, bridge, and a small pot (no LED driver) it works fine on DCC and tests perfectly with a 9V battery, but using an LED driver instead was recommended to me as a better option.

John

Just tested the setup with individual LED's that come with a shrink wrapped resistor and it works much better.  But the strips reduce the number of wires.

John

It really depends on the voltage coming into the regulator.  What is the DCC voltage?

@gunrunnerjohn posted:

It really depends on the voltage coming into the regulator.  What is the DCC voltage?

The power supply for the MRC Prodigy Express is 13.8V but it doesn't read that across the track

With
no current the voltage was 14.5 Volts. At 1 amp the voltage
dropped to 13.6 volts. At 1.6 amps, the rated output, the
voltage was 13.1.

John

Obviously, it's the voltage across the track that is important.  Also, there is a voltage drop of about 1.4 volts across your bridge, and there is an additional drop of around 4 volts across the CL2 part.  If you start with 13 volts, you end up with a maximum of around 8-9 volts output, that will barely light a 12V LED strip.

Here's the output current vs voltage graph for the CL2 constant current regulator.

Thanks John,

20mA is the rating.  Supposedly the input rating is 5-90V.

Maybe individual LEDs is the way to go with the LED driver or just stick to the Bridge - Cap - Pot (or resistor) method and the 12V strips.

John

You can wire the CL2s in parallel to up the total output (2 for 40 mA, 3 for 60 mA). Try it out on your breadboard and see if that helps. You might end up using the same amount of CL2s in the end, but it gives you another option.

@CK posted:

You can wire the CL2s in parallel to up the total output (2 for 40 mA, 3 for 60 mA). Try it out on your breadboard and see if that helps. You might end up using the same amount of CL2s in the end, but it gives you another option.

His problem isn't current, but rather input voltage, parallel connections aren't going to fix it.

What about this voltage regulator?

Available here.

John

John, that's a 5V output, much too low to light a 12V strip!

If you're marginally around 12 volts, the bridge rectifier and maybe a resistor to adjust brightness is probably the best bet.  Any regulator is going to drop the voltage more, and you don't have voltage to spare.

OK, read output as input.  Early Senility.

So far I have been wiring these HO passenger cars as you suggested.  I'll stick with that.

Thanks as always,

John