Thread: REN Booster
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Old 20th Oct 2012, 9:37 pm   #36
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Join Date: Nov 2010
Location: North Hykeham, Lincolnshire, UK.
Posts: 515
Default Re: REN Booster

Originally Posted by Nick Malvern View Post
... As far as I can see it will only supply bells wired to terminal 3, and will not help with running additional modern phones that have a 2-wire supply and derive their ring tone internally ...
Wow! 18 months on, I'd forgotten all about this, so I've had to re-read the thread!

The first thing, which was enshrined in the first post in this thread, was that the requirement was for a REN Booster to operate a number of vintage phones.

These will have independent access to the bell circuits and would, therefore, connect to my circuit on a dedicated bell wire.

However, if you ensure that a relay with a 4000Ω coil is used, or a relay + series resistor equalling 4k in total, the circuit will have a REN of 1, so two wire phones can still be added up to the maximum line limit in addition to older phones with a 3/4 wire configuration.
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