IRDOT 2

[beeman]

I am contemplating a whistle when entering/exiting a tunnel. Has anyone managed to parallel/double the in/out sensors on the Irdot2 module. I have 2 of these to hand but find the reflectivity/operation somewhat poor for the black u/s of a loco. This could be an advantage if I paint the underside white so the time duration for the Irdot relay enable time will be restricted to the time for the white reflective loco u/s to pass over the sensors.The distance will also need to be OK. If the IR transmitter/receiver are paralleled it will need only one unit for both directions. I would imagine the transmitter would need to be in parallel & the receiver in series.

I realise a reed switch would be easy, but this means a magnet on every loco, and a one shot timer to give a timed output. Any experience/ suggestions appreciated.

[Donw]

An alternative approach would be a short track circuited section which could trigger the whistle. The Irdot module could recognise other vehicles and give failed whistles.

Don

[beeman]

An alternative approach would be a short track circuited section which could trigger the whistle. The Irdot module could recognise other vehicles and give failed whistles.

Don

You set the 'grey matter' into gear with the suggestion of a track circuited section. Do you mean a relay switched by the loco passing over a 'broken' section of track. Relay ok on DCC if AC track fed thro rectifier, but then Tender pickups/metal coach wheels/coach lighting would trigger also. Not sure what you mean by 'failed whistles'.Having a white loco u/s or tape would give a timed period while loco passed without affect from rest of stock as long as the distance of the Irdot was adjusted as required. I stated previously the Irdot did not seem very sensitive to the black u/s but this was remedied on the bench, by removing the heatshrink from the sensors and replacing with outer from black coax cable, seems the end of the sensors was too restricted by the original heatshrink. Thanks for your suggestions appreciate clarification of 'failed whistles. Beeman.

[beeman]

After an afternoon on the bench I resolved this query, I have modified the irdot, which was an Irdot 1 originally to which I fitted a relay converting it to a 2. I have since altered it using a second infra red emitting diode, rescued from a redundant tv remote, and a IR photo transistor.This now switches the on board relay by either of the pair of IR transmitter/receivers, the additional pair are on 4 'fly' leads from the circuit board, strapped together with some black sleeving and tape. This will now, with positioning through the baseboard ok, switch an automatic whistle from both in/out of a tunnel portal from the one Irdot, job done.