Evening Christine,
I have a unique label I print for my Telephone Line Generator.
The front side says, "Telephone Line Tester". It has no batteries and no
power supply.
On the back, the label reads, "For Analog Systems Only"
"Do not use with any Digital
System"
I do not know of anything taking this device thru customs. It is in fact a
phone line tester.
Plug in the phone line, short the alligator clips together, and the LED
glows. This tells you the phone line is good, or at least some voltage is
present.
I can't imagine customs, Airport Security, or anyone else not letting it pass.
It is even built into a surface mounted telephone terminal block.
If they open it up and look inside, and they know nothing about
electronics, the may YELL for technical assistance. It contains one led,
one resistor, and one full wave bridge rectifier.
The purpose of the rectifier is so that the red alligator clip will always
be positive, no matter what the polarity of the phone line. It would work
without this.
However for the LED to work, the polarity must be right, and the full wave
bridge will always provide the correct polarity, no matter what the
polarity of the phone line.
However in a third world country one must consider such thing as
1. electricity challenges - frequency of service
Do most cities in the third world countries have phone systems? If
so, what is the voltage?
2. the instrument is not 'detained' at customs
I would like to see if that happens.
