Add in­frared de­tec­tors

Clive Heath­cote and Ann An­der­son ex­plain how in­frared de­tec­tors work, and how you can use them to add re­al­ism to the sig­nalling on your lay­out.

Model Rail (UK) - - Contents -

Clive Heath­cote and Ann An­der­son ex­plain how in­frared de­tec­tors work.

Is there any­thing more im­pres­sive on a lay­out than watch­ing a train pass a sig­nal and for that sig­nal to turn red? What’s even more im­pres­sive is then watch­ing that red sig­nal turn back to green. You prob­a­bly think that to do this in­volves com­puter con­trol and lots of com­pli­cated elec­tronic wiz­ardry. But that’s not true. In fact, it can be achieved quite sim­ply us­ing Heath­cote Elec­tron­ics’ in­frared con­trol boards.


You may have seen how white light, when shone through a prism, splits into the seven colours of the rain­bow (red, or­ange, yellow, green, blue, indigo and vi­o­let). Be­neath the red is a colour hu­mans can­not see. This is in­frared, which can be seen by snakes, frogs… and mo­bile phones. Heath­cote’s con­trol board emits and senses in­frared. Mounted be­tween the sleep­ers, it sends an up­ward beam of in­frared. When a train passes over the beam, the rolling stock re­flects it back to the con­trol board’s sen­sor. Mod­ellers have tra­di­tion­ally used things like reed switches, mag­nets, light-de­pen­dent re­sis­tors and cur­rent sen­sors for this type of train con­trol, but in­frared has key ad­van­tages: It works in the light or dark. Any item of rolling stock is de­tected. You don’t need to mod­ify your trains in any way. It works with both ana­logue and DCC con­trol sys­tems. In­frared de­tec­tion can be put to many dif­fer­ent uses on a model railway, from lo­cat­ing trains in hid­den sid­ings to au­to­mat­i­cally op­er­at­ing points. Heath­cote Elec­tron­ics’ first in­frared de­tec­tion board was named the IRDOT-1 (Infra Red De­tec­tion of Trains). The IRDOT-1 was de­signed for train lo­ca­tion for hid­den sid­ings or for au­to­mat­i­cally con­trol­ling trains (such as on back-and-forth ‘shut­tle’ se­quences. Since then, Heath­cote Elec­tron­ics has re­leased a num­ber of in­frared de­tect­ing boards for var­i­ous uses. To make your sig­nals work au­to­mat­i­cally, you’ll need the MAS Se­quencer and the IRDASC se­ries of boards. And the most com­pli­cated thing about them is their names!


The sig­nal half­way along Shap bank on Gra­ham Ni­cholas’ ‘Shap Wells’ is con­trolled us­ing Heath­cote Elec­tron­ics’ in­frared con­trol pan­els. See the Sum­mer 2018 is­sue (MR251) for more on this lay­out.


Above: Ju­lian Bir­ley has made good use of Heath­cote Elec­tron­ics’ in­frared con­trol pan­els on his Di­nor­wic quarry lay­out (fea­tured in the next is­sue). This shows how in­con­spic­u­ous the in­frared sen­sors can be.

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.