Headlight flickering in reverse DC

[alfsboy]

Hi

I have just finished painting ,re gearing and re motoring a US brass loco . I have put the headlight wiring  across the motor tabs .Its a SM LED with a resistor .It works fine forward as intended .Its flickering in reverse  however  when crossing my peco Insulfrog switches instead of being off all the time .Any fixes out there ?

thanks in advance for your trouble.

Martin

[34theletterbetweenB&D]

Improve the pick up efficiency of the loco, so that it doesn't briefly lose track supply. The giveaway is that you report the flickering over the dead crossings: that's the LED being lit by the back EMF of the motor when track supply isn't available.

[amdaley]

Could a stay alive capacitor be fitted ?

[cliff park]

I think he's looking for a stay dead solution

[alfsboy]

Thanks for your advice .No pickups on brass usually so it may be an unsolvable problem.Its picking  OK on tests .

[kevinlms]

Thanks for your advice .No pickups on brass usually so it may be an unsolvable problem.Its picking  OK on tests .

Perhaps the loco is actually only picking up with a small number of wheels. Check continuity with a multimeter.

[Silver Sidelines]

Not sure how relevant but the running lights and indicator board lights on a lot of my DC Bachmann DMUs start to flicker with use.  My problem is associated with build up of black deposits on the wheels (and I guess to a lesser extent deposits on the track).  Cleaning the wheels solves the problem.  It does intrigue me why the DMUs are affected as it does not appear to be an issue with any other loco.  Nor do I have a problem with Bachmann / Hornby Pullman coaches that are fitted with lighting.  The points are all electrofrog, the rolling stock has all metal wheels and with two exceptions there are no locos with traction tyres.  Answers on a Post Card?

 

Ray

[34theletterbetweenB&D]

In short, intermediate wiping contacts on the Bachmann DMU's between the excellent unpowered bogie pick up on the pin points, and the LED's. Difference between these and the Bach Met-Camm Pullmans which have the same design of pick up, these have soldered wiring from pick up to LED's. The addition of the wheel tyre contamination exposes evidence of other intermittent contacts in the circuits on the DMUs: replace the supplied connection paths with soldered on fine wires, and all is well.

 

There's a lot of this elimination of as much soldering as possible at assembly going on from the OO manufacturers from whom I buy product; some measure of the 'cost down' pressures they are under, leading to actions to reduce assembly labour input. Once sure that any new model is sound, it's out with the solder, soldering iron and wire to install my own reliable electrical connections as required.

[Silver Sidelines]

Thank you 34C for those helpful comments - I know exactly what you are describing.  The bent phosphor bronze contacts can also lead to a lop sided appearance if the contact on one side is bent more or less than the one on the other side. 

 

Thanks again

 

Ray