PJPro said:
Hospital grade means it has specs on low leakage currents returning to earth. So for them, they simply omit all the Y caps, since AC currents normally flow there. The non hospital grade actually filter much better. These filters are directional, so by adding your own extra Y caps is even better for filtering stuff from getting inside vs out.
compare diagrams page 12 http://www.schurter.ch/pdf/english/GST_general_product_information.pdf
I took a look at that data sheet last night, unfortunately before your post infinia. I was unable to arrive at the same conclusion as you....and went with the medical filters. These have now been shipped.
I'm really grateful for any help, advice or words of wisdom people are prepared to offer to help me through this first build. If people don't want to help, then please refrain from posting.AndrewT said:
You are saying that I can place a couple of caps from live and neutral to earth to replace these Y caps? I notice that the M80 variant of the medical filter is supplied with these caps.infinia said:
If I were to replace the Y caps, how do I go about working out the capacitance required?
Depends on what frequencies you are trying to reject. More C is better until the case size gets to big and the SRF gets in the way. So start with 2200 pF and maybe more staying with that case size no bigger. Mount directly to output pins with the leads trimmed short etc.
Which part did you order? those IEC input filters are really expensive, I use usually scavenge whatever I come across.
Which part did you order? those IEC input filters are really expensive, I use usually scavenge whatever I come across.
You can work it out I'm sure, if not maybe you can try to change your order to get the right IEC filter part.
Unfortunately, the goods have left the US and are at Stanstead (UK).
My solution would be to solder one lead of each cap onto the wires coming from the transformer and the other lead onto the earth wire. I'd then place these soldered ends into the crimps.
Is this regarded as a pucker solution?
My solution would be to solder one lead of each cap onto the wires coming from the transformer and the other lead onto the earth wire. I'd then place these soldered ends into the crimps.
Is this regarded as a pucker solution?
If it were my call (RF design guy) I would solder the caps real close to the filter case and dress it down so there's still room for the faston. Or just solder everything and ditch the faston.
Hmm. I could have spent less money and got a more elegant solution. It's a pity I didn't see your post before I placed the order.
What do these Y caps do for me? Can I live without them?
What do these Y caps do for me? Can I live without them?
The Y caps really add quite a lot to the input filter both common and diff mode. 20-50 dB at HF.
If your case isn't fully metal enclosed ie shielded then its added value isn't all that great.
We want our DIY projects to be all that they can be and a bit more, besides in engineering as in life everything is a tradeoff. Can you live without a chip amp even? probably
If your case isn't fully metal enclosed ie shielded then its added value isn't all that great.
We want our DIY projects to be all that they can be and a bit more, besides in engineering as in life everything is a tradeoff. Can you live without a chip amp even? probably
Maybe I'll see what they sound like without the caps first. I'm assuming that these filtered modules won't sound any worse than an unfiltered module......that would be a kick in the teeth!
imho the difference is small. Medical filters will offer you a basic protection and rf will enter your amp at the other 'inputs' (audio in + speakerout) too.
And for the most annoying power line born switching distortions, those IEC filter inlets are useless...just toys..😉
regards
And for the most annoying power line born switching distortions, those IEC filter inlets are useless...just toys..😉
regards
sorry this stuff is real not toys
That's right you have to consider the whole (ie all in's and outputs). This powerline filtering is serious biz and getting more important everyday. Probably most garbage is due to computers and other household consumer devices that use cheap SMPS. the most effective solution is to attack the noise issues from whense they come. It's cheap (and easy if you know how) to add a couple of caps to get 30 dB of noise reduction in the band of SMPS high harmonic conductive emissions. I use toroids on all my computer ins and outs esp when interfaced with external audio and video.
So what does all this mean is... you are probably better fitting your new part on your household PC IMO is what your best option is.😀
Juergen Knoop said:
That's right you have to consider the whole (ie all in's and outputs). This powerline filtering is serious biz and getting more important everyday. Probably most garbage is due to computers and other household consumer devices that use cheap SMPS. the most effective solution is to attack the noise issues from whense they come. It's cheap (and easy if you know how) to add a couple of caps to get 30 dB of noise reduction in the band of SMPS high harmonic conductive emissions. I use toroids on all my computer ins and outs esp when interfaced with external audio and video.
So what does all this mean is... you are probably better fitting your new part on your household PC IMO is what your best option is.😀
Well, the delivery from Mouser arrived today.......and it looks like I've ordered the wrong fuse holder. Damn! This is particularly disappointing as I entered into an online web chat with one of their tech guys (Chuck) to make sure I got the right one.
Here's a picture...
Basically, the module accomodates two pole fusing and I purchased a single pole fuse holder. I explained exactly what I needed. I assumed that the single pole fuse holder would come with a shorting bar or something.
Damn!
Have to say that the module itself is very well made though......not that it makes me feel any better!
Here's a picture...
Basically, the module accomodates two pole fusing and I purchased a single pole fuse holder. I explained exactly what I needed. I assumed that the single pole fuse holder would come with a shorting bar or something.
Damn!
Have to say that the module itself is very well made though......not that it makes me feel any better!
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