>>>if I remember correctly from way back, when you insert a coin in the coinbox
>>>slot, it raised a cam which would then fall after the coin had passed.This
>>>is what made it quite hard to push the coin into the box. The falling cam
>>>is what generated the pulses according to coin value. The coin would then
>>>pass down a chute where it was checked for weight diameter thickness to
>>>ensure it was a valid coin. If not it would drop out of the chute. Only if
>>>it made it to the end of the chute (i.e. a valid coin) would it operate a
>>>switch called the mask. This switch is what produced the open circuit. I
>>>hope that is clear, I know what I mean anyway :-)
>> When the mask contact is activated by a valid coin reaching the end of the
>> chute it allows the coin pulses to be sent to the line. Contact CPON3 is what
>> produces the 60 ms open circuit period.
>I presume it also helped make it difficult for someone putting
>a normal phone in parallel on the line.
5k resistor and a diode in series placed across the dial impulsing
Dial normally (diode not conducting).
Current reversed from exchange on answer (to unlock coin slots).
Dial (sending coin pulses as diode now conducting).
If C&FC requires break pulse, flash receiver rest.
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