AC Polarity

[mvdveek]

Im currently looking at the AC polarity in my system. But cant seem to get my multimeter to work the way I want it to.
I was wondering if any of you know how the RSP-1570 and the RMB-1575 are wired internally.

[mjb]

The quickest way would be to pop the covers and look!

The way to test AC phase/polarity is to:

1. determin the phase pin of the outlet, using a neon screwdriver tester, and mark it - phase (live or hot) is the pin where the neon lights!
2. Connect the power cable to the device, and power on.
3. Using your voltmeter (set to AC volts), measure the voltage between the earth pin of the power outlet, and a metal point (not paint) on the chassis. Note this value.
4. Invert the power cord, and repeat the above.
5. "In Phase" will be with the power cable in the orientation giving the lowest measured voltage. Mark the cable, or socket to indicate the correct orientation.

When the 1570 and 1575 are both plugged in, there should be no measurable voltage between the two chassis.

Don't light yourself up when playing with household power, it can hurt!

[mjb]

The measurements must be taken with no other connectins made.

I've just remembered the 1575 doesn't have a ground pin, so my post above might be misleading...

Another way to do it is to:

1. Connect your processor to a power outlet, and power it on.
2. Set the meter to AC Volts.
3. Touch one of the meter probes on an earth point of the processor, and hold the other. Note the reading.
4. Turn off, invert the power plug, turn on, and repeat step 3.
5. You will want to leave it set to the orientation with the lowest reading.

Next,

6. Power up all the components, and WITH NO OTHER CABLES CONNECTED, measure the voltage between a good earth point on each device.
7. Change the orientation of the components power plug and repeat the measurement (not the processor, thats set).
8. "In phase" is the orientation with the lowest voltage reading.

Its hard/impossible/irrelavent to test anything with a switch mode PSU.

Again, BE CAREFULL when messing around with power!

[mvdveek]

Thx!

I'll go fidle with it some more this weekend and will see if it will lead to improvements