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701B Princess voltage issue?

Started by AL_as_needed, June 27, 2017, 07:59:22 PM

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Alex G. Bell

Quote from: TelePlay on July 09, 2017, 08:46:33 PM
Alex,

What load or loads (an just resistors or lamps) would you suggest he put across the terminals to test the wall wort he has for voltage with his meter?
What's relevant is what it's delivering to what it's actually powering.  So he should measure the voltage across one of the lamps when it's lit, not across some other load. 

Since he did not describe whether he has more than one key phone with lamps connected there is no way to know how many lamps light when a line is in use.  If the number of lamps lit at any time varies according to which line he is using or some other variable he should check the voltage across one of the lit lamps for the least number and greatest number of simultaneously lit lamps.

It's a safe bet that if the power source is unregulated it's delivering much more than 12V into a single lamp since a single lamp only draws 42mA, just 1/7th of its load capacity.  OTOH if it's regulated it's still 20% over the rated lamp voltage and 9% over the max. voltage.


AL_as_needed

Quote from: Alex G. Bell on July 09, 2017, 09:15:12 PM
Since he did not describe whether he has more than one key phone with lamps connected there is no way to know how many lamps light when a line is in use.  If the number of lamps lit at any time varies according to which line he is using or some other variable he should check the voltage across one of the lit lamps for the least number and greatest number of simultaneously lit lamps.

It's a safe bet that if the power source is unregulated it's delivering much more than 12V into a single lamp since a single lamp only draws 42mA, just 1/7th of its load capacity.  OTOH if it's regulated it's still 20% over the rated lamp voltage and 9% over the max. voltage.

Keep forgetting to check into the 565hk for this.....been sitting in my project corner (with the princess!).

Anyway, to clarify a few points; There is just the one phone connected to this wall wort in question. On this phone (or into it) is also wired the WE spokesman. Regarding the bulbs, only one is illuminated at a time, based on which key is depressed. Outside of that, there is nothing else activated by the keys, except the last one that puts power to the spokesman when depressed/lit.
TWinbrook7