Micron MR603 question on P1 & P2

[collectors]

Hi, i got 2 receivers doing the same thing. on the P1 & P2 directional lights. If i join the lights up for a test at 3.5v & appropriated resistors all works fine. If i then reverse the polarity, the lights, the colours change ends. So! all is good. But when i connect to receiver terminals P1 & P2 i get red in the front & nothing in the rear when forward is selected. When i select reverse i get red in rear & nothing in the front. The led's are 2 pin red/white revers polarity to change colour. This is the same on 2 x MR603 receiver's. Yet on a smaller loco using a DelTang, works perfectly. Any suggestions ??. Thanks

 

[PhilP]

How many LEDs, and what value series resistors are you using?

Up the resistors to at least 330 Ohms.

PhilP

 

[collectors]

How many LEDs, and what value series resistors are you using?

Up the resistors to at least 330 Ohms.

PhilP

Thanks PhilP, will try that tomorrow & get back as time for a break because i blown one or the receivers. Thats a quick £40 out the window. You think they would build in a safety reverse polarity circuit into the units. lol. The resistor's are 220 as they was a bit brighter.

 

[PhilP]

Thanks PhilP, will try that tomorrow & get back as time for a break because i blown one or the receivers. Thats a quick £40 out the window. You think they would build in a safety reverse polarity circuit into the units. lol. The resistor's are 220 as they was a bit brighter.

Red and white LEDs have differing forward voltages.. When you connect them back to back, the theory gets very complicated, and the 'normal' calculations for resistors go out of the window.

Unless you go for three-wire LEDs, the resistor values are a compromise between one colour 'stealing' all the current, and getting both to light.

PhilP

 

[JimmyB]

If you are using bi colour (white/red) two wire LEDs then they will only work correctly with 660 ohm resistors, ask me how I know, it is because to the different values of the colours, any thing less and the easy path is taken.

 

[collectors]

Thanks everyone, had some spare 560 resistors & all is working fine now. I was using the same lower resistors that i used on an earlier DelTang receiver. Not all receivers are the same. lol.

 

[JimmyB]

Thanks everyone, had some spare 560 resistors & all is working fine now. I was using the same lower resistors that i used on an earlier DelTang receiver. Not all receivers are the same. lol.

I think you will find the issue is the LEDs