2 ms·
> POTS phone wires typically have 45 volts DC across them when the phone is on-hook. Don’t you mean -48 for the US phone system?
by gumby 4y ago
> POTS phone wires typically have 45 volts DC across them when the phone is on-hook.
Don’t you mean -48 for the US phone system?
- anonymousiam 4y ago48VDC is specified, but in my experience, it varies. The bottom of the article says the same: On-hook voltage: 40-50 V DC
- gumby 4y agoPretty sure from memory AT&T spec’d negative voltage to reduce corrosion.
- anonymousiam 4y agoAh. I did not see that you meant to emphasize the negative vs. positive voltage. It's true that it's negative, but given that phones are polarity independent, it doesn't really matter. I was expressing the voltage as an absolute value.