COP 20.00 (2000%) Times, Reactive Power Energy Source Generator,

[listener191]

Hi Void,

Attached

1. power switch circuit with timing
2. timing circuit
3. zero cross circuit

The cap switch is a variation on a circuit that Mario has already tried.

Barry

[listener191]

Sorry didn't attach

[listener191]

Hi TinselKoala,

Attached is a scope shot showing differential v grounded scope probes.

I have shifted the traces vertically so you can see there are two traces, otherwise they align perfectly.

As you can see there is no skew.

Barry

[TinselKoala]

Hi TinselKoala,

Attached is a scope shot showing differential v grounded scope probes.

I have shifted the traces vertically so you can see there are two traces, otherwise they align perfectly.

As you can see there is no skew.

Barry

Thanks for posting the shot... but.... it's always something. I don't know which channel is the diff probe and which the passive probe, the channels are set to different attenuations, there is at least half a volt DC offset coming from somewhere on one channel, and it _does_ look to me like there is a couple degrees skew. Look at where the zero crossings are, don't try to match peaks. This means, of course, that the baselines for the two channels have to be in the same place vertically... and they aren't.
Further, why isn't your scope actually computing the phase angle between the two displayed signals? I've seen several screens, like this one, where the phase angle computation comes up "asterisks".


ETA: I see why _this_ screen doesn't compute the angle, you are asking it to compute with a channel that doesn't have a signal. One wonders why you haven't asked for the phase angle between the two signals that _are_ displayed.
 
If both probes are hooked to the same signal, shouldn't the voltages agree? Yet one is indicating ten times the voltage of the other.


Please do this if you have a chance. Set both channels and both active and passive probes to the same attenuation, connected to the same sine wave signal from a signal generator at the same frequency as your DUT . Set the vertical positions so that both of the baselines are _exactly_ on the center graticule marker. Set the scope's computations to compute the phase angle between the two signals of interest!

[listener191]

Hi Tinselkoala,

The Rigol scope is only a day old and so I am still learning its operation.

The differential probe has x20, x50 & x200 selections. I kept the x200 setting as I cant make the comparison with the x10 ground probe, exactly as you requested.

The previous shot before was done quickly as to not disturb my setup, henec the use of Chl2 & Chl3. The rigol measurement functions are over whole cycles so any display that shows less than a whole cycle results in blanked fields.

The phase shift according to the measurement function is 0.865deg.

When I tried to increase my vertical resolution from 20V/div to 10V/div there was an overange situation.

I tried the setup on my old Owon scope and set the max resolution I could, and measured 10us (approx 0.2deg) skew between the probes.

Which ever one you take,  0.865deg or 0.2deg  the skew is under a degree and so has little effect on the AxB (VxA) function computation.

Barry