I have a rectifier diode (I think thats what its called?) That I want to replace because it has broken legs, but I cant find the exact model, and am wondering what do I need to know to find a replacement/equivalent?
The diode is a FMU34S, Ill add a photo of it as well.
The diode tests good, at least from what I can tell, but I would like to replace it if possible.
I would like to replace its twin also, a FMU34R, if possible.
Can someone please let me know what I need to know to find a suitable replacement?
Any help is appreciated!
The diode is a FMU34S, Ill add a photo of it as well.
The diode tests good, at least from what I can tell, but I would like to replace it if possible.
I would like to replace its twin also, a FMU34R, if possible.
Can someone please let me know what I need to know to find a suitable replacement?
Any help is appreciated!
Step #1 in your journey is to study the manufacturer's engineering datasheet. I have attached it to this message. Carefully follow the icons called "8" and "9" to the part of the datasheet where package drawings are found. The "8" and the "9" tell you whether the part is a (dual diode with common cathode) or a (dual diode with common anode).
Now go search digikey.com for a dual diode in the same package, with the same or better electrical specifications. Use their Parametric Search feature found (here) .
It's not difficult but it does take several minutes of concentration and focus.
Now go search digikey.com for a dual diode in the same package, with the same or better electrical specifications. Use their Parametric Search feature found (here) .
It's not difficult but it does take several minutes of concentration and focus.
So from the data sheet, I need to find a dual diode that can handle 400v in the same package? Is the package a "Center Tap" diode or what is the package called? I dont see it anywhere on the datasheet, unless i just dont know what im looking at. And I see the Specs for the FMU34S are, but I dont know what they mean, do I need to worry about all of them when finding a replacement?
Sorry for being such a noob, but I dont know much about electrical component specs.
Sorry for being such a noob, but I dont know much about electrical component specs.
So the package would be TO-247-3? Correct?
Would this be a suitable replacement, or am I way off?
https://www.digikey.com/en/products/detail/taiwan-semiconductor-corporation/HER3005PTH/18720593
What I dont understand is where does it say how many amps the diode can handle in the datasheet? The forward voltage current? Is that the samething as Amps?
Would this be a suitable replacement, or am I way off?
https://www.digikey.com/en/products/detail/taiwan-semiconductor-corporation/HER3005PTH/18720593
What I dont understand is where does it say how many amps the diode can handle in the datasheet? The forward voltage current? Is that the samething as Amps?
Ok cool thank you. So to boil it down, the 400 volts in the data sheet is the amount of voltage the rectifier can handle, and the Forward Current (20) is the amount of Amps it can handle? And as long as I find one in the same package (TO-247-3) that can handle at least those specs, I should be alright?
Is there any other specs I should be looking at, or worrying about?
And is there any trick to finding the rectifiers "twin" or do I just do the same thing with the other rectifier and find any one that can handle the specs, or do they need to be matched like transistors do?
Sorry for asking so many questions, but I just want to understand how to do this, so next time I know how to do it
Is there any other specs I should be looking at, or worrying about?
And is there any trick to finding the rectifiers "twin" or do I just do the same thing with the other rectifier and find any one that can handle the specs, or do they need to be matched like transistors do?
Sorry for asking so many questions, but I just want to understand how to do this, so next time I know how to do it
There are other specs, which sometimes will be important too, but we have no information about the application.
The twin, with the diodes reversed, might be a little more difficult to find.
Note the original package is TO-3PN. It is non-isolated.
The twin, with the diodes reversed, might be a little more difficult to find.
Note the original package is TO-3PN. It is non-isolated.
It is for a car audio amplifier.
And yeah it seems like the its opposite is tougher to find. Would it be ok to just get the one and mix them or is that not a good idea?
Ok so make sure the replacement is the same. Is that what TO-3PN means, denotes that its non-isolated?
And yeah it seems like the its opposite is tougher to find. Would it be ok to just get the one and mix them or is that not a good idea?
Ok so make sure the replacement is the same. Is that what TO-3PN means, denotes that its non-isolated?
Can anyone tell me if these would work for replacements? Their voltage is higher, but that shouldnt be a problem right? (Just a bit overkill?)
https://www.digikey.com/en/products...0?s=N4IgTCBcDaIIIAUAqBmADAEQGxoEIGE4BxEAXQF8g
https://www.digikey.com/en/products/detail/microchip-technology/apt30d60bctg/1494481
Ive been trying to find a "matching set" of 1 pair common anode and common cathode, and the one I found earlier does not have a counterpart, at least not from what I can find. (The one pair common Anode, is tough to find in the package I need 🙁 )
These were the best "matching" pair Ive found, but they are still slightly different, (One is a 30 amp, one is a 27 amp) but they are both from the same manufacturer and look like just about everything else is the same.
And they arent TO-3PN's but from what I can tell, that is just for mounting and heat sink purposes? My amp has a metal bar that goes over them and screws to the aluminum so that shouldnt be a problem, right?
I guess what Im asking is;
Its ok if the rated voltage is 600v instead of 400v, and 30 amps/27 amps instead of 20 amps?
And the slight 3 amp difference on the purposed newer ones shouldnt be an issue right?
And TO-3PN is just for different heatsink mounts and as long as I can mount it with thermal paste to my aluminum case, that shouldnt be an issue right?
Thanks for you guys' help and input
https://www.digikey.com/en/products...0?s=N4IgTCBcDaIIIAUAqBmADAEQGxoEIGE4BxEAXQF8g
https://www.digikey.com/en/products/detail/microchip-technology/apt30d60bctg/1494481
Ive been trying to find a "matching set" of 1 pair common anode and common cathode, and the one I found earlier does not have a counterpart, at least not from what I can find. (The one pair common Anode, is tough to find in the package I need 🙁 )
These were the best "matching" pair Ive found, but they are still slightly different, (One is a 30 amp, one is a 27 amp) but they are both from the same manufacturer and look like just about everything else is the same.
And they arent TO-3PN's but from what I can tell, that is just for mounting and heat sink purposes? My amp has a metal bar that goes over them and screws to the aluminum so that shouldnt be a problem, right?
I guess what Im asking is;
Its ok if the rated voltage is 600v instead of 400v, and 30 amps/27 amps instead of 20 amps?
And the slight 3 amp difference on the purposed newer ones shouldnt be an issue right?
And TO-3PN is just for different heatsink mounts and as long as I can mount it with thermal paste to my aluminum case, that shouldnt be an issue right?
Thanks for you guys' help and input
BigKat- the parts you noted are well-over-rated for your application. The higher current rating merely means the diodes are larger physically, and the device is designed at the chip level to handle a larger voltage. This means the capacitance of the device will be larger, but should not hurt in Audio operation. No problem.
BTW- I worked in semiconductor materials and devices for about 40 years or so.... both high speed (like terrabit optical) and electrical signals and power- like for electric cars, power stations and cell phone transmission.
Ok good to know. It shouldnt matter my replacements are a slightly different mounting style right?
The old ones are TO-3PN style that have a hole to mount to a heat sink, and the purposed newer ones dont have that hole, but as long as I can still mount them to the heat sink that shouldnt be a problem right?
The old ones are TO-3PN style that have a hole to mount to a heat sink, and the purposed newer ones dont have that hole, but as long as I can still mount them to the heat sink that shouldnt be a problem right?
Correct- as long as you can get a clamp of some type to hold the part firmly to the heat sink- this is important. And, use a thin layer of heat sink compound between the heat sink and the back of the part, you should be fine.
Alright cool. thank you.
Yeah the amp has a bolt on metal rail to attach the rectifiers to the heat sink so that shouldnt be a problem, and will definitely use some thermal compound. I just wanted to make sure I understand how to replace rectifiers so if I ever have to do it again, I will know how.
Thanks again.
Yeah the amp has a bolt on metal rail to attach the rectifiers to the heat sink so that shouldnt be a problem, and will definitely use some thermal compound. I just wanted to make sure I understand how to replace rectifiers so if I ever have to do it again, I will know how.
Thanks again.
These rectifiers are usually in the DC-DC converter section. Standard ultrafast (35 to 50 ns) usually work well. Higher current is better, higher voltage may give a slightly higher forward voltage drop.