Re: Insulated Rail Joints.

["B." <gunzel412@dingoblue.gunzel.net.au>]

Mark Bau <markbau@altavista.com> wrote in message
B5E1F389.15CDA%markbau@altavista.com">news:B5E1F389.15CDA%markbau@altavista.com...

>> You may notice, around points, steel boxes (about 1m sq)
>> mounted on posts. These are Impedance Bonds and their
>> purpose is to allow the 1500v traction return current to
>> flow around the Block Joint but still provide electrical
>> isolation for the track circuit.

> Similar to a tuneable joint coupler where a track circuit
> like for a road crossing has to go through an insulated
> joint.

Except the Impedance bonds pass DC, and block AC, where as the joint
couplings of whatever flavour pass AC, and block DC.

Tunable joint couplings?  You must have Coded Tracks... |-)

Back to those original IRJ's, why again do you need then at a plain buffer
stop?  Wouldn't you just have one impedance bond, tie the 2 rails to it, and
the centre tap to the crossbond?

--
B.

Email - gunzel412 at dingoblue dot net dot au
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