Hi. I have tested the voltage outputs of nearly all my Blue transformer.
Basically, on low power there seems to be 6 volt, my highest on full power was 18 volts and the highest reverse voltage was nearly 28 volts.

I understand I will have to fit some sort of voltage regulator and it seems I will need to reduce the voltage down to 4 volts based on the lowest transformer output if I want the lights to work when the lowest power is applied.

I also understand i will need to fit a bridge rectifier in the power supply to the LED"S.

My aim is to run three head lamps and 2 tail lamps [2mm LED's], running in forwards, and change over to the same when in revers. I also want to fit a flashing orange lamp [ 2mm flashing LED ] on the roof. [ of course there is stuff all room for this ]

I figure that I should run all LEDs from the power supply, and switch on the earth circuit.

In this first test case, I am working on my 3080 and it seems that the reverse mechanism works by changing the earth for the field coils.

I am hoping to mount all the lights in the body and have 4 contact points on which the body will rest to provide the current. [
this will enable removing the body for servicing without have to undo wires

I may be being optimistic, but am a stubborn bastard and I wont be defeated
[ apart from my lack of knowledge about electronics ]

There are lots of deal on Ebay for LED's, Bridge rectifiers[KPB310??]and voltage regulators [ LD1117V33 voltage regulator or 7804 ]

Hope someone can help me get on the right track

Dereck

Edited by moderator 11 January 2018 11:19:09(UTC)  | Reason: Not specified

Thanks tiono. I have been searching for solutions and going round in circles. I will check this out and report back with the results.

All the best. Dereck

well, I have finally got my bi colour LED's. But, in the mean time I have found 2 problems.

firstly, the testing on the breadboard shows me everything to do with the front and rear lights works with the engine running. I do however have to figure out a method of making a reversing mechanism. I can do it mehanically but that is going to be slightly messy, time consuming and probably not easily replicated. If any one has any ideas on how to achieve this i would be grateful?

Secondly, while the engine is running, the flashing LED goes haywire on low power and goes out anything above say 1/4 throttle on the 278 tranny I am using. The light comes back on at the lower power settings again, but it does not flash regularly like it does at all power settings without the loco connected in the circuitry. That's got me stumped.

If anyone has any ideas on what is up here i would be please to get the help.

I am hoping there might be some micro device out there [ like an on/off relay possibly ] that can be used. I realize I my have to use a bridge rectifier and CCR in this circuit as well [ or do I ]. Probably time I drew up the circuits I have and posted them here. might have to figure out that camera again.

Dereck

Sounds like a project for IXLDOC..

pdf 3080 led schematic.pdf (31kb) downloaded 28 time(s).



Its been a while but time flies when you are having fun. Here is a schematic of what I was originally intending, and found the problems listed above. My son is home for a few days so I got his help doing this drawing. Howard [ IXLDOC ] has helped me with ideas for the reverse switch, which I will experiment with while my son is home.
I'm also looking forward to my Bands trip to Brisbane early April next year [ same time as the Commonwealth games but not going there ]
I haven't worked out the proper values for the resisters yet but have used ones recommended by the LED suppliers. I have lots of different ones now, also about 100 in4001 diodes. I bought a couple of cheep digital voltmeters to connect up on the bread board so that I could monitor voltages but those 2 things have been a pain in the ass.
I was supposed to go fishing with a mate on Saturday Morning but it rained most of the day. Yesterday was fine but overcast all day and today started out the same. Its sunny outside right now and the temperature has started to go up. Thursday and Friday here was up to 29 degrees. getting a bit hot for comfort. Overcast means nice a cool. Probably not as cool as where Ake lives, but I think that's a bit low for me.

a wee note about the schematic. 4 of the LED's are warm white/red and the central electrode is positive. That's because I original though we could earth the leds through the body of the loco, but I think I went wrong there so hence the way the diagram is now. The CCR's from Digikey [ NS150010YT1G ] are mentioned above. It has been mentioned that the red LED's could effect the performance of the white ones.

All the best for Christmas everyone.

Dereck

This photo shows the three white front and 2 red rear lights lit up

this other photo shows the 3 rear lights and 2 front light lit.

If you look carefully in the next 2 photos you can see the very small size of the bridge rectifier and the CCR




We still have a problem with getting the flashing light to work consistently. At low tranny settings below 1/4, it flashes normally. above that it starts to get erratic then goes out completely.

Dereck

Edited by user 27 December 2017 00:22:40(UTC)  | Reason: Not specified

Got the flashing LED performing now by putting 3 x 1000 Ohm resistors is series. The seem to work right up to about 3/4 throttle which is ok for a shunter.
Dereck