Operation Overview; Loop Problems; Mode Of Operation Of The Ksm-3 - tams elektronik KSM-3 Manual

Loop module for digital model railroad layouts

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KSM-3

2. Operation overview

At the loop points in two-rail-systems, different polarities meet with each other. As soon as a

vehicle bridges the differently polarized sections when driving in or out the terminal loop a

short circuit occurs.

In digital layouts loop modules generally have to adapt the polarity within the terminal loop to

the one outside. In case the polarity outside the terminal loop would be altered, different

polarities would meet with each other at the transition to the next booster section. Thus the

problem would be misaligned only.

As soon as a locomotive bridges the sectioning point between differently poled sections inside

and outside the loop, the KSM-3 changes the polarity within the terminal loop. The response

time is extremely short, as the KSM-3 already detects the voltage drop at the switchover to a

short-circuit. In consequence, the KSM-3 is able to react within milliseconds before the voltage

breaks down due to the short circuit.

The sensitivity for the polarity reversal depends on the applicated voltage and for that reason

has to be set via a trimm-pot individually. In order to allow the precise setting a LED on the

KSM-3 lights up as soon as the sensitivity has been set optimally (for the particular layout).

That way you safely prevent wheels, current collectors and rails from damages and make sure

locomotives pass the sectioning point without jerking.

Integrated switching of the points

The KSM-3 can also control the position of the points. The loop control works independently of

the points control, so that the connection of the points is not obligatory. Coil driven points

can be connected directly to the output for the points. In order to be able to use motor-run

points, an adapter for motorised turnouts AMW-1 (item no. 72-00076) or AMW plus (item no.

72-00176) is additionally required.

The points are switched automatically as soon as the locomotive reaches one of the two

sectioning points (simultaneously with altering the polarity). The two sectioning points are

assigned to a particular correct position of points. That way externally switching the points

does not interfere with the safe procedure.

6 | Operation overview

Figure :

Short circuit problem at the loop points

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