If you feed the non-detected zones through a similar diode-drop arrangement (handful of cents for a few diodes arranged back-to-back), then there is no change in track voltage as you drive into detection zones.
Alternatively, if you want current measuring coils, suggest looking at the devices LocoIO and Current Detection modules available in kit form from Hans De Loof. They are available through a model shop in Holland/Belgium (can't remember which). They talk LocoNet, so integrate easily with other LocoNet/Digitrax kit.
I use Hans De Loof LocoIO boards, but my current detection coils come from the MERG DTC-8 kit. That pairing works together extremely well, with the DTC-8 circuits powered by the 5v DC available from the LocoIO.
> -----Original Message-----
> From: Digitrax@yahoogroups.com [mailto:Digitrax@yahoogroups.com] On
> Behalf Of Christopher Zurek
> Sent: 23 May 2013 10:43
> To: Digitrax@yahoogroups.com
> Subject: [Digitrax] Block Detector (was Digitrax Throttle Redesign)
> I'm not a big fan of the Digitrax BDL block detectors because they use diode
> drop detection. This causes a voltage drop in the blocks being detected. I
> used them on a demonstration layout I built in the past.
> I'm looking at using detection that has current detection coils. No voltage
> Chris Z.
> ----- Original Message -----
> > From: "Tim Franklin" <tim@...>
> > To: Digitrax@yahoogroups.com
> > Sent: Wednesday, May 22, 2013 11:17:17 AM
> > Subject: Re: [Digitrax] Re: Digitrax Throttle Redesign
> > > In conclusion there are other Digitrax products that I feel are in a
> > > more dire need of redesign than their throttle. A redesign of their
> > > PMxx, BDLxxx and SExx come to mind even if it comes to reduction in
> > > capabilities.
> > > These
> > > devices can be a pain to install due in part to the soldering to
> > > edge connector.
> > Not even a re-design needed - there are already break-out boards
> > commercially available to take the edge connector to a series of screw
> > terminals. See for example
> > http://www.coastaldcc.co.uk/products/digitrax/ (no connection other
> > than as a satisfied customer, scroll down to 'BDL168 Break Out
> > Board'), and from memory there is at least one guy in the US producing
> > something similar.
> > In my view, Digitrax need to buy out or subcontract to one (or more)
> > of these people, and ship the screw terminal connector in the box. I
> > don't see a lot else wrong with the BDL168.
> > Regards,
> > Tim.
> > ------------------------------------
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