Codegen 350XA supply

[rievax_60]

Re: Codegen 350XA supply

I have just tried loading the 12v on my 350XA to 6A. Both waveforms change very little. The duty cycle increases by a few percent and the peak drops to 28v.
milesy, I am curious to see your 12v anode waveform with the 2Ω load.

[milesy]

Re: Codegen 350XA supply

sure rievax ill post it up later on tonight....trouble is im not getting anywhere near the peak of 28v

[milesy]

Re: Codegen 350XA supply

here you go rievax.......here is both anode and cathode waveform with no changes to CRO settings just moved the probe......set on 2v/div with a x1 probe


IMGP9597.jpg by Adrian Miles Photography, on Flickr


IMGP9596.jpg by Adrian Miles Photography, on Flickr

[rievax_60]

Re: Codegen 350XA supply

I think your CRO might be causing the anode waveform to look asymmetrical, because the asymmetry isn't being reflected in the cathode waveform.
Does it change shape when you change the vertical position. Or try the other channel.
If the CRO was really set to set on 2v/div, the 12v output would be less than 2v. What was the 12v output measuring?
Better check the CRO calibration and that the inner vertical gain knob is set to is CAL position if it has that.

[milesy]

Re: Codegen 350XA supply

ok rievax your sort of right.......what i found was that there is a button on the cro to zoom in on a section of the wave - you can see it in the above picture marked TRIG VIEW PUSH

for whatever reason this button was activated even though it wasnt in its active state - so where i said i had it on 2v/div above what i was getting was actually peaking at around 30v - so it seems that my wave is correct .......... poor thing is getting a bit old now and is showing a few funny faults.

so if i said i was confused before - now i really am because i havent actually replaced anything and yet the supply seems to be operating correctly?????

as for the shape of the wave well i have to agree with you - it doesnt show on the rectified trace so the strange shape must be being caused by the CRO - but i have no idea why

[Th3_uN1Qu3]

Re: Codegen 350XA supply

as for the shape of the wave well i have to agree with you - it doesnt show on the rectified trace so the strange shape must be being caused by the CRO - but i have no idea why

Maybe you need to adjust the probe compensation. Your scope should have a square wave output for that purpose - and if you're lucky it might even work. Otherwise, use a signal generator for this purpose. A soundcard capable of 96 or 192kHz set to generate a 1kHz square wave is fine for this.

Adjust the compensation trimmer on your CRO probe until the top and bottom of the square wave are parallel with each other and show no overshoot (peaks) or undershoot (rounding of edges).

[milesy]

Re: Codegen 350XA supply

Maybe you need to adjust the probe compensation. Your scope should have a square wave output for that purpose - and if you're lucky it might even work. Otherwise, use a signal generator for this purpose. A soundcard capable of 96 or 192kHz set to generate a 1kHz square wave is fine for this.

Adjust the compensation trimmer on your CRO probe until the top and bottom of the square wave are parallel with each other and show no overshoot (peaks) or undershoot (rounding of edges).

yes the test generator works......never thought of adjusting the cro prope but makes sense........ill have a look tomorrow