lm317
Can I just remove the LM7812 and replace it by a LM317 ?
In which area(s) is the LM317 better than the LM7812 ?
Thanks !
No, pinout is absolutely different and incompatible. The LM317 needs two resistors that need to be chosen to set the output voltage: It might also need different capacitors on input and/or output for best operation.
LM317 - 3-Terminal Adjustable Regulator
While I haven't looked into it, I've read it has lower noise than the common fixed-output regulators such as 7812. Get the datasheets of both and compare them, that should answer a lot of questions.
As for the Murata part, it would be a hard sell for me to consider a switching regulator, regardless of the price. It's hard to believe it wouldn't generate substantially more noise than any linear regulator.
LM317 - 3-Terminal Adjustable Regulator
While I haven't looked into it, I've read it has lower noise than the common fixed-output regulators such as 7812. Get the datasheets of both and compare them, that should answer a lot of questions.
As for the Murata part, it would be a hard sell for me to consider a switching regulator, regardless of the price. It's hard to believe it wouldn't generate substantially more noise than any linear regulator.
The 723 voltage regulator will be better than any 3-pin regulator.
The downside is the number of additional components, and limited power capability (300mA).
Fortunately it's easy to increase power handling by adding an NPN power transistor.
With the BC140 it will match the 7812, but for more power even the old workhorse 2N3055 will do the trick.
The downside is the number of additional components, and limited power capability (300mA).
Fortunately it's easy to increase power handling by adding an NPN power transistor.
With the BC140 it will match the 7812, but for more power even the old workhorse 2N3055 will do the trick.
Attachments
The 723 voltage regulator will be better than any 3-pin regulator.
The downside is the number of additional components, and limited power capability (300mA).
Fortunately it's easy to increase power handling by adding an NPN power transistor.
With the BC140 it will match the 7812, but for more power even the old workhorse 2N3055 will do the trick.
Hi friends, I recently want to replace my NAS switching supply with a linear one. Is this circuit suitable for use?
I need 12V 3A output, just replace BC140 with 2N3055 ok?
Thanks a lot!!
I accept the LM317 as the simplest solution. IT IS NOT A DROP IN REPLACEMENT.
It depends on how far you want to go.
Universally the Shunt Regulators are the quietest.
Have a read of http://www.wenzel.com/documents/finesse.html
It depends on how far you want to go.
Universally the Shunt Regulators are the quietest.
Have a read of http://www.wenzel.com/documents/finesse.html
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A 2N3055 should be ok, but make shure it's Hfe isn't too low. Any NPN Darlington will be betterHi friends, I recently want to replace my NAS switching supply with a linear one. Is this circuit suitable for use?
I need 12V 3A output, just replace BC140 with 2N3055 ok?
Thanks a lot!!
As for the Murata part, it would be a hard sell for me to consider a switching regulator, regardless of the price. It's hard to believe it wouldn't generate substantially more noise than any linear regulator.
You would consider even a free sample a "hard sell"? I tried it (7805SR) not expecting much, and I like it -- plus the Murata 7812SR-C is a direct replacement for 7812 as OP seems to want. Now that I've tried it, I think it's worth $10...
It's switching at 260kHz, so...
LM340T-12
If you are after a drop-in replacement try the LM340T-12.
It has better specs than the normal LM78xx series and in some areas even better than the LM317 afair. And it remains stable with some C at the output.
There are probaly better fancy shunt regs and so on - but it is drop-in and cheap.
joe
If you are after a drop-in replacement try the LM340T-12.
It has better specs than the normal LM78xx series and in some areas even better than the LM317 afair. And it remains stable with some C at the output.
There are probaly better fancy shunt regs and so on - but it is drop-in and cheap.
joe
The 723 voltage regulator will be better than any 3-pin regulator.
The downside is the number of additional components, and limited power capability (300mA).
Fortunately it's easy to increase power handling by adding an NPN power transistor.
With the BC140 it will match the 7812, but for more power even the old workhorse 2N3055 will do the trick.
Do you have any measurements of this circiut. The 723 is a "ancient" device, I guess new regulator devices could have same specs with less number of additional parts.
1543
If you are after a drop-in replacement try the LM340T-12.
It has better specs than the normal LM78xx series and in some areas even better than the LM317 afair. And it remains stable with some C at the output.
There are probaly better fancy shunt regs and so on - but it is drop-in and cheap.
Thank you very much Joe: you are right, I am looking for a drop-in replacement, and of course something better than the LM78xx'
Thanks again guys,
Universally the Shunt Regulators are the quietest.[/URL]
They're quiet, but not as quiet as the "SuperTeddy" -- what may you find, however, is that noise is of less importance than PSRR and Output impedance when it comes to the manner in which sound is influenced by the regulator.
And speaking of regulators, while it's not a "drop-in-replacement" I would recommend the LT1963A as one of the best OEM regulators -- with the appropriate bypassing as recommended per Linear's datasheets.
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