35kV that a high voltage supply LOL current minute though.
Anything above SELV is dodgy but strange things happen at the higher voltages. Creepage and clearance becomes an issue, best to bury tracks on inner layers of a PCB to minimise exposed copper, that's what I do, then apart from components creepage requirement has gone and general spacing's are a lot smaller.
IPC-2221B table 6.1 is your initial go-to guide.
Anything above SELV is dodgy but strange things happen at the higher voltages. Creepage and clearance becomes an issue, best to bury tracks on inner layers of a PCB to minimise exposed copper, that's what I do, then apart from components creepage requirement has gone and general spacing's are a lot smaller.
IPC-2221B table 6.1 is your initial go-to guide.
2100V at 250 mA max. is non-beginner and very lethal stuff. Be careful.
I think I start to know why you stopped with Linear Audio
Yes I have started to draft my will
Jan
This looks like it would be a solid part but my input voltage isn't 12v higher then my output. Basically the input and output is roughly the same and looking to get a constant regulated voltage. A friend is sending me his design over and will look at what parts he used. I guess I can add another 12v from another secondary winding to it and get it to work or add another 12v from another transformer. Once i get the regulator from him I will be able to come up with a few ideas.
You want higher voltage than at output stage? You can wind a few extra turns on the toroid and connect this in series with the secondary winding to give extra voltage for the IPS/VAS
Correct the IP and VAS used higher voltage rails then the driver and output transistors. I am using multi tap/center tap toroids and have additional 12v and 18v secondaries. The smaller toroids are center taps but i do not believe they have the addition windings however I can take the 12v from the larger ones and add them together and have the extra 12v. I would have to limit the current tho as currently the smaller of the amps is using 300VA and 50-80VA and the larger is using either 800VA or 1KVA and 100VA. I am interested in seeing how he did it and what parts he used - there is 4 x 1kuf caps on board and if it was pure DC coming in, i don't think there would be a need for that much filtering.
I don't understand what you mean when you say you would have to limit the current
The IPS and VAS portion use smaller VA toroids...using the 12v tap from the 1kva toroid connected to the 45v 80va toroid I would assume would generate a lot more current then needed for the regulator...again this is just a hunch. Right now I am making these as add ons but eventually plan to add them to my PSU and save on connections and size.
They will only draw the current they are designed to, the fact there is more available is irrelevant. BTW, I wouldn't advice connecting the secondary of one transformer to another. I've never heard of that being done and I'm pretty sure it's a bad idea. At the very least it could cause hum problems
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I got too many of the toroids to replace them with 12v higher. I will have to look at my friends and see how he did it.
Its no problem at all. If you have a small additional xformer with say 2 separate 12V secondaries, you can put one secondary in series with each of the secondary outputs of the main xformer to create a higher AC voltage, which you can use with an additional rectifier to get the extra DC. It's a common thing to do and there is no reason why it would cause hum or whatever.
Jan
Thanks Jan. I've heard of adding a few extra windings to elevate levels for IPS circuitry, but not that. Additional transformer seems a simpler thing to do
You just have to make sure the small xformer has two totally separate secondaries. A xformer with a center tapped secondary will obviously not work unless you can separate out the center tap wires.
Any linear regulator circuit needs a higher input voltage than the regulated voltage it puts out. This is called drop out voltage. If you have for instance 400V DC non regulated available you can set this IC for 385 V regulated output voltage (provided you don't have large ripple voltage). All can be calculated when you know what filter cap values you have etc. You don't need an extra 12V winding or something like that. Just see what you have as unregulated DC and then adjust the LR8 so that it has at least 12V less output voltage. Add up the Uf of diodes and ripple voltage and it will work just fine.
Again, this IC can only deliver a maximum of 30 mA so using one for reach channel seems a logical choice.
You can not regulate 400V input voltage to 400V output voltage with linear regulators. Or am I misunderstanding what you are telling ?
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