RDR-290

Posted by: Ravik on 10/21/2013

Sir,

I want to manufacture 300 piece of 75 watt LED Driver with High efficiency and Power Factor

And I found RDR-290 is best fit in my requirement. Hence my output V & I is not same so I used PI software and did not understand few things.

1) Same values as RDR-290 gives error while optimise in PI Expert and shows different value of primary inductance in PIXLs. So which value to be select?

2) RDR Spreadsheet showing LNK410 and Schematic LNK420EG.

3) RDR Spreadsheet LNK410 Full ILIMITMIN =5.30, ILIMITMAX =6.20 and datasheet of LNK410/420E/L is 4.90 and 5.70.

4) Full and Reduced power current limit is same in datasheet for LNK410/420. It means any cap from 10uf to 100uf can be used for BP pin?

5) Why V pin resistor (RV2) not used in Schematic when it provide the best output current regulation for non-dimming.

6) A corner frequency of R15, C9 & C10 is not 50 or 100Hz.

7) Will it effect on efficiency if I use EI40 or cosmo EE4215 core instead of PQ3230 for cost reason.

Thanks,

Ravik

Comments

1. Follow the PI Expert

2. Use LNK 420EG

3.Follow the datasheet and PI Expert values

4.Follow the recommended value on PI Expert

5.You can use RV2 if you still need regulation improvement.

6.Whats the question?

7.Bigger core/transformer allows you to reduce winding losses which will give you better efficiency

Sir,

1) I am unable to optimize, Input Highline, Eff .92, KP .56 & VOR 130 with PI Expert as RDR 290

6) As per Datasheet Filter Resistor (R8) and Capacitor (C5)

These two components form a low pass filter (pole). The corner frequency (1/2×π×R8×C5) should be where fL is the minimum line frequency to prevent line frequency ripple modulating the FEEDBACK pin. A corner frequency of 50 Hz results in a power factor above 0.9 at 230 VAC input.

Thanks

Ravik

Hi,

1. Can you send the PIExpert file. Let us see at what section you are having some problem so that we can improve the optimization.

6. Yes you are correct it is a low pass filter but the modulation is not a problem for the converter to operate. You can even reduce the capacitance for better THD at some point.

Regards,

PI-Jono