Distracted by a Camera Flash

This week my modelling activities were distracted by a camera flash, at least on Tuesday, Wednesday and Thursday nights.  I wanted to model a TW taking photos on my layout.  I thought that this modelling project would be easy.  The first thing I did was to talk to Barnacle Bob and see what he used on his layout.  Mosquito Creek has a photographer supposedly taking a photo of a young lady sitting on a rocky outcroft, when we know he is taking a photo of a train crossing the brilliantly built trestle bridge with a train running across it.  So Bob’s solution was to purchase a WEISSMANN model.  In the current environment, that would cost truck loads from Europe to ship and conversion rates would send me broke.  Surely I could manufacture one myself.  I thought about using an NCE Mini Panel to send a signal to turn on an NCE light-it wait ¼ of a second and then turn it off.  My issues is that when I issue a turn it on command to a light-it it is a slow turn on. The intensity of the light ramps up over a second.  Not an instantaneous ‘on’ like a flash from a camera.  I was going to detect the presence of a loco on a section of track and via an NCE BD20 and then that would trigger a function on the mini panel, which would activate the light-it sequence.  I thought this would be easy, but the cost of a BD20 was a slight stumbling block in my current modelling budget and the slow turn on was the real killer.  I think I might have some 3^rd party detectors in the cupboard that I might try and see if they could trigger a Mini Panel input, in place of the NCE BD20, but this solution looks dead and buried, especially when the turn on from the light-it is rather a slow ramp up – not a simulated camera flash.

I had another solution.  It was that the loco on the track itself would just trigger power through a bridge rectifier to light an LED.  I have set it up so this solution works and will only trigger on a powered axle, not each axle in a train.  This is achieved by having isolated sections longer than a wheel tread before and after the section connected to the bridge rectifier.  So in a test run, my 6 wheel loco will fire off the camera 6 times, once for each powered wheelset.  The flash was quick to fire and then went out.  A contributor to this short flash, is that the section of track that is the trigger section is only about 4mm long and the wheel on a moving train is quickly on and then off the trigger.  Sure a certified TW might take than many photos in quick succession for each locomotive, but, ideally I’d like the circuit to fire maybe once or even twice for each loco – maybe once per bogie.  So I’d like the first wheel to fire the camera, and then it would then charge a circuit that introduces a delay of maybe 2 to 4 seconds before it resets.  That way the camera will fire maybe once per bogie or even once per locomotive, depending upon the speed it is going through the section.  Alternatively, the first wheel might charge the circuit, which then the second or maybe third or fourth wheel will initiate a camera flash, as the other wheels contribute to the charge.

I need the help of an electronics guru.  I really don’t want to spend $50 - $100 on a commercial product.  Surely there are lots of people who would like this gimmick on their layouts.  My circuit diagrams are below.

The other activities undertaken this weekend was watch the NMRA-X event on Saturday night for a few hours before I bailed.  I have almost completed a presentation for an upcoming NMRA-X event.  I built 26 more pallets and have 12 that been painted and added to the spares box.

I did revert to doing a little work on my QR HO wagons by adding a small amount of weight between the centre sills on the first two completed wagons.  Maybe next week I will do some more on my 4 half bit QR HO wagons and maybe they will enter the paint shop as well.