Durst TRA450

Hello all,
I am setting up a Durst L900 with CLS 450 colour head and TRA 450 transformer.The timer connections on the transformer are confusing me! In addition to the mains power input and colour head sockets,there is a socket marked 'timer 220v' and a socket marked 'timer input'.It would appear that a timer can be powered by the transformer rather than directly from the mains,and that the timer output is then fed into the 'timer input' socket.This would then presumably bypass the mains power input to transformer cicuit.Is this correct? I would value the opinion of anyone who has used one of these before I blow it up !

Yes, you got it right, except for the sentence "This would then presumably bypass the mains power input to transformer cicuit." which may be correct but I failed to understand (my fault perhaps).

This way of connecting the timer is terrific, and with my highest surprise it has been discontinued in later models, and I still wonder why.

The key point is that, by connecting the timer in this way, the timer doesn't turn on and off the whole power supply, lamp, etc. but it drives only a relay control WHICH IN TURN powers on and off the whole power supply, lamp, etc.

This means that, with an itty-bitty 10W max. load timer, you can drive a >250W monster as the Laborator, as the timer is connected only to a skinny relay which absorbs almost no power from it.

Wonderful, isn't it? Enjoy.

Thanks for confirming my theory!

I am certainly looking forward to using the L900.It seems to be packed full of nice design ideas,and is very solid too.