Bottlehead Forum

General Category => General Discussion => Topic started by: hpleung on December 24, 2021, 11:14:12 AM

Title: Mainline (Strange Voltage Measurement)
Post by: hpleung on December 24, 2021, 11:14:12 AM

Hi,

I am doing the voltage measurement for the first time at step "Clip the black lead of your Digital MultiMeter to 31U. Clip the red lead of your DMM to 32U. Make sure that the metal ends of the two test leads cannot touch each other. Set your DMM to AC volts in the appropriate range."

When the switch is on - i read a 118.2 AC Volts.

When the switch is off - i read a 24.6 volts. ==> Should not this be zero?

Thanks.

Title: Re: Mainline (Strange Voltage Measurement)
Post by: Paul Birkeland on December 24, 2021, 05:21:24 PM

What you're measuring is the voltage difference between the powerline neutral and a wire that is connected to nothing but running right next to a wire carrying 120V, so there may be a bit of coupling going on there.  There's really no oomph behind this though, when the power transformer primary wiring is complete that should go away. 

Title: Re: Mainline (Strange Voltage Measurement)
Post by: hpleung on December 25, 2021, 11:18:07 AM

Got it.  Thanks. Will check the voltage again later.