Hi, can any one help me out?
I am trying to understand how LGB point/switch motors work using AC. I am familiar with the use of DC in other scales but now need to wire in some signals to be operated according to the setting of a route. I have attached the LGB supplimentry switch to the point/switch which will give an electrical output according to point/switch setting but what next?
Any ideas?
cheers
Geoff
The Vendee and Pacific Railway
US trains en France
Geoff,
the supplementary switch is basically a double pole double throw switch pack broken down into two separate switches. There are six terminals total for the two switches. Each switch has three terminals, comprising a centre ‘common’ pole and a terminal either side of the common, depending on the selection of the switch motor.
One possibility is to use one of the switchpacks using the centre terminal as the power feed and the terminal to each side as the 'red' connection and the other as the 'green' connection on your signals. The other switch assy could be used to power frog polarity or a track isolation circuit to stop the train on a 'red' signal.
Using a multi-meter it is easy to check which terminals are 'active/conductive' as the switch machine is moved from side to side. As far as AC power being used to power the 'DC' switch machine, then the AC supply is 'rectified' to single wave DC in the LGB switch control box.Thanks very much Tim very helpful.
So the LGB switch machine reqires DC and the output from my Massoth DCC switch boxes or the LGB analogue switch box is also DC.
I will have to run a seperate supply of DC to the supplementary switch and wire it as you describe, this will power the signal arm and the lamp.
The idea is to use a pair of signals to indicate the route selected on a remote junction, the point blades being well beyond the range of my failing eyesight.
I will give some thought to the other uses you suggest once the signals are opertating properly.
kind regards Geoff
Geoff,
the suplementary switch pack assembly, attached to the LGB switch machine, utilises ‘straight’ DC power. The actual switch machine uses a ‘modified’ DC, i.e., AC power that has been rectified to single wave DC (not strictly the same as DC power). Someone may have a circuit to allow DC to be used to operate the switch machine. If straight DC is used, then it is twice the power strength of the single wave DC and should the switch jam (say the point blades are obstructed), then the switch machine may be damaged. Using the ‘half strength’ single wave DC, the switch machine could be powered indefinitely, supposedly and still not suffer damage.