MUR860 rectifying bridge question

[Alcaid]

Would the MUR860's be able to rectify a 300VA 2x24VAC toroid in a dual rectifying bridge setup? Would it need cooling? The MUR860's have an IF(AV) of 8A, and the toroid will give (150/24=) 6,25A per secondary.

What do you think?

It is going to be used in a subwoofer-amp with linkwitz transform circuit, so I think the bridges will have plenty to do (because of the extra gain at lower freqencies)

 

[UrSv]

IMHO, Yes.

However, I would have chosen something beefier myself.

 

[Alcaid]

Any suggestions to other discrete diodes to use that can handle more current, and are "audiophile"

 

[UrSv]

Well, for sub use I would not myself worry to much about "Audiophile" rectifiers. Maybe any brand MUR1560/MSR1560 or the ISL9 series from Fairchild could do?

 

[Alcaid]

Anyone tried the MUR3020PT, good for 30A

http://www.onsemi.com/site/products/summary/0,4450,MUR3020PT,00.html?tax=553

edit: ops... looked in the datasheet, it's not 30A, but 2x15A.

 

[peranders]

What is the load? If you read between the lines the diode can 16 A under some circumstances.

I have chosen these in my rectifier bridge but I can't really figure out how much those diodes can take in a rectifier application.

 

[peranders]

Anyone tried the MUR3020PT, good for 30A

http://www.onsemi.com/site/products/summary/0,4450,MUR3020PT,00.html?tax=553

edit: ops... looked in the datasheet, it's not 30A, but 2x15A.

Works probably alright.

EDIT: but you can connect the diodes in parallel and get some more than 15 A.

 

[Alcaid]

What is the load? If you read between the lines the diode can 16 A under some circumstances....

I haven't buildt the amp yet, but it's intended for a 4ohm 12" sub.

 

[Alcaid]

What will happen with the rectified DC voltage if one (or more) diode gets damaged by a to high current?

 

[Peter Daniel]

What will happen with the rectified DC voltage if one (or more) diode gets damaged by a to high current?

Usually a fuse on primary blows off. I had the bridges blowing on my A75 amp (because of inrush current) and this was always the case, no damage to amp or speakers.

 

[ashok]

Parallel operation .

This is probably a silly question.
The MUR1660CT and MUR3020PT have their anodes tied together. Can they be used in parallel ?
To make a bridge they will need a device with cathodes connected together. I can't find such a device in this range.
Otherwise they have to be used in parallel !
Have I overlooked something ?
Thanks.

 

[Magura]

The ones from ON semi can be paralelled. I dont know about the other manyfacturers versions.

Magura

 

[peranders]

If you only have one type you must have at least 3 packages but yu should use 4. If you one common cathode and one common anode you will need one of each. But if I'm not mistaken there is only one type of the MUR3020.

The be short: Just tie the two anodes together, then you will have the diodes in parallel.

 

[nemestra]

The be short: Just tie the two anodes together, then you will have the diodes in parallel.

The two diodes will have slightly different turn-off characteristics, even when they are in the same package. By parallelling these, you may be removing a little of the advantages gained by the use of soft recovery types. The two diodes will switch off at different times, thus prolonging the noise generated.

The use of a single diode with higher current capability would be better.

James

 

[stappvargen]

nemestra wrote:

The two diodes will have slightly different turn-off characteristics, even when they are in the same package. By parallelling these, you may be removing a little of the advantages gained by the use of soft recovery types. The two diodes will switch off at different times, thus prolonging the noise generated.

Please remember the application (subwoofer). I don't think any swiching garbage will be heard when used <100Hz. In other words, go parallell if you must. Or, even better, use a standard rectifier bridge4 good for at least 25A, it should be cheaper.

/Niclas