Mark
I see what you mean now, but what kind of arrangements are the diodes in at the AC end? It looks like a half wave rectifier but the diodes are the wrong way round aren't they?
Can anyone explain what the diode in parallel with the resistors and the MBR1045s on the DC output side are doing?
I see what you mean now, but what kind of arrangements are the diodes in at the AC end? It looks like a half wave rectifier but the diodes are the wrong way round aren't they?
Can anyone explain what the diode in parallel with the resistors and the MBR1045s on the DC output side are doing?
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But perhaps you have already shown your current thinking in this post?
http://www.diyaudio.com/forums/powe...ld-linear-12v-power-supply-7.html#post3712707
"I myself certainly would not select or pay for Cree's Silicon Carbide diodes; instead I'd probably choose something like the Fairchild FFPF30UP20S. It's rated for 30 amps, 200 volts, and most importantly, it's an honest to goodness soft recovery diode with the softness parameters (ta, tb) measured and specified on the datasheet. Non repetitive peak surge current is 300 amps. It's way cheaper than the Cree diode too: Mouser has 1129 of them in stock, on the shelf, for $1.24 each in quantity 10 (link)"
I bought from Mouser (link in post25) recently after being put off many times by their high UK pricing.
I paid for the goods + VAT + postage and packing and including all fees and stated import fees and taxes.
I then had to pay the messenger £11 at the door, because they (the Courier) had added on their fee for handling an import from outside the EU.
Never again !
DigiKey are just as bad.
ONsemi added on fees that almost exceeded the cost of the product to send an order into the UK.
Then USPS asked for their fee (by letter) a couple of days after delivery. USPS claimed I had a contract with them and their bill was almost as big as the cost of the goods. I fought this one and eventually won my case. There was no contract between me and USPS. The contract was between ONsemi and USPS. ONsemi had added on so much for postage and packing they could easily settle with USPS and still make a profit.
It does not seem to be taxes on imports into the UK that is the problem.
It's the fees (sometimes hidden) attached by all the parties from the seller to the customer that makes up the exorbitant cost.
I paid for the goods + VAT + postage and packing and including all fees and stated import fees and taxes.
I then had to pay the messenger £11 at the door, because they (the Courier) had added on their fee for handling an import from outside the EU.
Never again !
DigiKey are just as bad.
ONsemi added on fees that almost exceeded the cost of the product to send an order into the UK.
Then USPS asked for their fee (by letter) a couple of days after delivery. USPS claimed I had a contract with them and their bill was almost as big as the cost of the goods. I fought this one and eventually won my case. There was no contract between me and USPS. The contract was between ONsemi and USPS. ONsemi had added on so much for postage and packing they could easily settle with USPS and still make a profit.
It does not seem to be taxes on imports into the UK that is the problem.
It's the fees (sometimes hidden) attached by all the parties from the seller to the customer that makes up the exorbitant cost.
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I have not tried this experiment.
What happens when each rectifier in a bridge rectifier is replaced with two (or three) diodes in series.
If using Schottkys the voltage drop penalty would still be less than/similar to conventional diodes.
Apart from cost increase, with the standard/ typical supply arrangement, what changes ?.
Simulation anyone ?.
Dan.
What happens when each rectifier in a bridge rectifier is replaced with two (or three) diodes in series.
If using Schottkys the voltage drop penalty would still be less than/similar to conventional diodes.
Apart from cost increase, with the standard/ typical supply arrangement, what changes ?.
Simulation anyone ?.
Dan.
I've now had a half dozen orders from Mouser without any problem. You should contact Mouser in the UK and get it refunded.
But we digress...
Hmm, the Fairchild diode that Mouser-USA sells for USD 1.60, are on the Farnell UK website for GBP 1.09. (link). At today's exchange rate that's 14% higher, although I'm the first to admit I have no idea how V.A.T. affects the comparison. And, what do I know, perhaps Farnell UK also tacks on hidden fees, after-the-fact fees, government fees, and imported-goods fees, even on items that have "624 in UK stock for next day delivery", like these Fairchild diodes.
Farnel sell from the UK.
There are no import taxes and no middle men demanding fees for a service they didn't provide.
VAT is added at 20% and we all know that as fact. It's not hidden.
Mouser and Digikey are not selling from the UK.
They have UK websites that quote prices in GBP that bear no relation to the final cost of the imported product.
There are no import taxes and no middle men demanding fees for a service they didn't provide.
VAT is added at 20% and we all know that as fact. It's not hidden.
Mouser and Digikey are not selling from the UK.
They have UK websites that quote prices in GBP that bear no relation to the final cost of the imported product.
The point of the forum is for those with more knowledge to share it with those less blessed Andrew, not to gloat about it! I was asking straight questions about the diodes on the output and the diode in parallel with the resistors, so how about sharing your knowledge in a straight answer?
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Whew, that's good to hear. Farnell has the Fairchild soft recovery diodes in UK stock for next day delivery (post #29), and just now I also checked all of the semiconductors needed to build a Quasimodo V4 board. All of them are in UK stock for next day delivery, on Farnell's UK website. {for the low-Rds MOSFET, Farnell stocks "substitute#2" as shown on the Quasimodo V4 Bill of Materials, the IRLU8726. Its Rds is 0.0058 ohms.}
A pair of ordinary four diode bridge rectifiers that are used in the typical arrangement for supporting a dual secondaries transformer.
CRC filtration whereby the diode limits sag so that transformer current isn't wasted excessively into the resistor and therefore bass power isn't wasted.
That is for cost effective dual mono
That was an older schematic--the MBR1645's used as series elements, will work better if relocated to the "amplifier board side of" the dc umbilical cable.
How much voltage would I loose from the cap-bank without this diode (during this "bass power request")?
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