Thanks Salas! I just ordered the ones from Hong Kong. Hopefully they are legit.
Thanks for looking at the adds for me.
2SK117-GR TOSHIBA Low Noise Audio Amplifier J-FET, x20 | eBay
Thanks for looking at the adds for me.
2SK117-GR TOSHIBA Low Noise Audio Amplifier J-FET, x20 | eBay
Glad to hear these are legit!
I am thinking about including an A/C line filter before my 2 power transformers. Building 2 separate +/- 15vdc@ approx. 150mA CC for a total draw of about 600mA DC. Using 2 Shilchar Custom Magnetics R-20 transformers rated at 15-30VA 18VAC. What would be an appropriate A/C line filter to use? I see there are both single stage and dual stage filters available. Would one filter shared by the two transformers be sufficient or would it be best to use a separate filter for each transformer?
Power Line Filter Modules | Filters | DigiKey
I am thinking about including an A/C line filter before my 2 power transformers. Building 2 separate +/- 15vdc@ approx. 150mA CC for a total draw of about 600mA DC. Using 2 Shilchar Custom Magnetics R-20 transformers rated at 15-30VA 18VAC. What would be an appropriate A/C line filter to use? I see there are both single stage and dual stage filters available. Would one filter shared by the two transformers be sufficient or would it be best to use a separate filter for each transformer?
Power Line Filter Modules | Filters | DigiKey
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Wondering about proper fuse selection for my project.
I am using 2 of these Silchar R-20 R-Core transformers with the primaries wired together in parallel in my remote transformer/rectifier box.
They are 120VAC primary 2X18VAC secondary. The only other spec I have is that the R-20 is shown to be on the spec sheet 15-30VA. Doing the math it seems as though @15VA the current draw would be .125A an @30VA would be .25A per transformer on the primary. X2 transformers would be .25A @15VA and .5A @30VA.
What current rating and time delay fuse would work best in my application?
I am using 2 of these Silchar R-20 R-Core transformers with the primaries wired together in parallel in my remote transformer/rectifier box.
They are 120VAC primary 2X18VAC secondary. The only other spec I have is that the R-20 is shown to be on the spec sheet 15-30VA. Doing the math it seems as though @15VA the current draw would be .125A an @30VA would be .25A per transformer on the primary. X2 transformers would be .25A @15VA and .5A @30VA.
What current rating and time delay fuse would work best in my application?
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Primary current +300% slow blow for this size category (transformers pull inrush current when energized like motors do). Those R-20 are 20VA each so 40VA together. 40/120=0.33A * 300% = 1A Slow Blow or better 0.5A Slow Blow to each one.
I feel using R-core has got no much benefits as the regulator itself cleans almost all the noise. Consider Toroid has got an advantage of non leakage of flux and stray magnetic fields. R-Core has got less regulation and top and above all the regulator is shunt so no matter what transformer you have the regulation is super fast hence I feel its right to choose toroid in the application as its magnetic leakage will be minimum with shunt toroid is best.
another important parameter is how its wound many companies these days are winding it as primary and secondary are both wound overall the core rather than winding for primary and then winding for secondary separately. Hence the advantage is also lost but do consider that the shunt itself cleans up almost all the noise enters into your stage. Do rather worry about your rectifier use a ultrafast diodes instead of normal ones to remove those spikes but i still feel the shunt will take care of the spikes also.
salas i have used silchar cores even on larger transformers what I felt it had little bit of lack of low frequency grip compared to a solid EI or Toroid. I tried from a transformer manufacturer with primary and secondary winding done as whole. The designer said that the regulation is quite better in toroid than in R-core.