Trying to go back to my roots from my electronics days and I though I ensure the CRO I got for free worked after being in storage after all these years. So I thought I post here what I was measuring, or trying to measure.
Depending on how the pics upload I thought I share what I measured, so I can't be too sure which pics will stack 1st on this post.
The reason I got this thing out was to see the diodes switching off and to see whether I could trace visually on a 50MHZ CRO the ringing that occurs and whether that follows onto the supply rails of 15-17vdc.
With The initial measurements I was almost shock and was unsure why I was getting clipping on a secondary of the transformer. I then used another preamp I had, and that same clipped waveform that was taken after the secondary. Still unsure of the measurements I didn't know whether the CRO was faulty or the testing at certain points was incorrect to give such a clipped waveform. As I said, I haven't done this for a while! So then it occur to me that I had to disconnect the psu PCB of the secondary winding of the transformer and measure the transformer without the load Once I did this, I got a waveform that resembles close to a normal waveform. The CRO is set on 0.5v/division, with a 10x probe, I'm not game enough to measure the primary with this set up, but you can see and get the idea that 230V in is not exactly a pure waveform, even if the measurements are taken of the secondary. You can see that it distorting on the peaks. To get a pure waveform you need to connected up to some mains regeneration unit and recreate the 230vac. No power supply reconditioning is going to resolve this issue.
You can also see from the initial pic with the clipped waveform that there is a spike where the diode is turning off under load with the psu connected, however I'm unable to see the ringing that occurs from it.
Depending on how the pics upload I thought I share what I measured, so I can't be too sure which pics will stack 1st on this post.
The reason I got this thing out was to see the diodes switching off and to see whether I could trace visually on a 50MHZ CRO the ringing that occurs and whether that follows onto the supply rails of 15-17vdc.
With The initial measurements I was almost shock and was unsure why I was getting clipping on a secondary of the transformer. I then used another preamp I had, and that same clipped waveform that was taken after the secondary. Still unsure of the measurements I didn't know whether the CRO was faulty or the testing at certain points was incorrect to give such a clipped waveform. As I said, I haven't done this for a while! So then it occur to me that I had to disconnect the psu PCB of the secondary winding of the transformer and measure the transformer without the load Once I did this, I got a waveform that resembles close to a normal waveform. The CRO is set on 0.5v/division, with a 10x probe, I'm not game enough to measure the primary with this set up, but you can see and get the idea that 230V in is not exactly a pure waveform, even if the measurements are taken of the secondary. You can see that it distorting on the peaks. To get a pure waveform you need to connected up to some mains regeneration unit and recreate the 230vac. No power supply reconditioning is going to resolve this issue.
You can also see from the initial pic with the clipped waveform that there is a spike where the diode is turning off under load with the psu connected, however I'm unable to see the ringing that occurs from it.
