Not since the early 80’s when I was fixing b+w vidicon security cameras.
I’m not sure when they first came out but they are in my February 1973
Edition of the “Fairchild Semiconductor Linear Circuits Catalog”.
Although the patent for the Lm317 was in 1971.
US patent 3617859
Not much has changed in 40 years.
Te Lm317 requires fewer external parts and is easier to use.
I’m not sure when they first came out but they are in my February 1973
Edition of the “Fairchild Semiconductor Linear Circuits Catalog”.
Although the patent for the Lm317 was in 1971.
US patent 3617859
Not much has changed in 40 years.
Te Lm317 requires fewer external parts and is easier to use.
It can be used for positive and negative supplies: that is only partly true. There is no true negative version. Any positive 3 pin reg can also be used for negative supplies by using it to GND....
LM723 can put out 150 mA but not at 5 V out and 30 V in to give an example. It is way better than LM317 but that should be clear just from looking at the specs. It is also less easy to implement and requires external parts and thus extra board space. Features that don't give a warm feeling to designers.
You know what wins: the part that is cheapest, not the part that is best.
LM723 can put out 150 mA but not at 5 V out and 30 V in to give an example. It is way better than LM317 but that should be clear just from looking at the specs. It is also less easy to implement and requires external parts and thus extra board space. Features that don't give a warm feeling to designers.
You know what wins: the part that is cheapest, not the part that is best.
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Jean-Paul..hehe
You are right. 0.5W is quite decent, but for diy where the best solution is the cheapest one it might be a little too low. We all tend to use some old transformer with not very ideal secondary voltages which results in high dissipations in most cases.
And I can't agree more. 317 is cheap and easy to work with. If you don't need current regulation and such things than 723 might be too complicated.
Best regards
You are right. 0.5W is quite decent, but for diy where the best solution is the cheapest one it might be a little too low. We all tend to use some old transformer with not very ideal secondary voltages which results in high dissipations in most cases.
And I can't agree more. 317 is cheap and easy to work with. If you don't need current regulation and such things than 723 might be too complicated.
Best regards
Oh, I don't agree on the "diy = cheapest solution". We can make things that are far better and too expensive to manufacture. I don't use old parts, maybe I'm different. I'm in this to make stuff that is super nice and really exotic. Things that I could never afford to buy if it were manufactured. So, cost and complexity is not important to me: performance is the most important. The cost of the chips and board space is minuscule compared to cost of a nice box, for example.
He he..
We we are all different. I also hate to use old components but on the other hand threre is not everything ready available in the middle of the night when many of us try to ,,work,,.
Another 317 for current limitation of course and than 2 in parallel for even more current and so on. Like those 500W amps containing 3886 ... and of course than you can add power transistors and so on. Different solutions, we are all different..
What about all those ultra modern chips? Great stuff, thank you, I agree, but what will happen when you will try to repair after decade? Will that great component still be available? And of course will be original or not working fake? Like all those nice double fets....and so on.
All this is only my opinion so no hard feelings. So here comes my conclusion. If you want to build linear psu go with something available cheap and reliable (like723 which was original question), something what could be serviced for a long time, otherwise buy or build (if you are skilled enough) smps.
Cheers
We we are all different. I also hate to use old components but on the other hand threre is not everything ready available in the middle of the night when many of us try to ,,work,,.
Another 317 for current limitation of course and than 2 in parallel for even more current and so on. Like those 500W amps containing 3886 ... and of course than you can add power transistors and so on. Different solutions, we are all different..
What about all those ultra modern chips? Great stuff, thank you, I agree, but what will happen when you will try to repair after decade? Will that great component still be available? And of course will be original or not working fake? Like all those nice double fets....and so on.
All this is only my opinion so no hard feelings. So here comes my conclusion. If you want to build linear psu go with something available cheap and reliable (like723 which was original question), something what could be serviced for a long time, otherwise buy or build (if you are skilled enough) smps.
Cheers
No we don't. Those who do try to save 10 to 20 Euro on a new toroid by using an old unsuitable transformer and generating useless heat by wasting power that they also pay every month. Not economical. Not green. Not smart. And certainly not a good reason not to choose a good reg.
If you're in DIY audio it is not wise to go for cheap or easy. Easy = cutting corners that many manufacturers do. Probably one of the reasons you ended up in this hobby
Go for the best as your self built device will be more expensive than ready made stuff anyway and you already took the "non-easy" direction.... Why go for mediocre ? Look around you, almost everything is already mediocre. But the choice is yours of course.Take a look at our LM723 power supply design. Just a bit more complicated than LM317 designs. Tajzma, reliable on the long term and smps don't go together hand in hand
At work I have linear 24 V 10 A power supplies that have been in service since 1979 and no one has failed yet. I won't see a smps live that long !
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Jean-Paul
I agree with you completely and I'm using old components only for tests in the middle of the night when everything else is closed. I also agree with you that cheapest way to diy something is to buy it. But most of other people don't. There is a lot young guys around and also a lot from other parts of the world and many of them can't just go and buy new transformer. In quite few cases is even 10e problem so they recycle. It is not green I agree but we can't stop them. This summer has been hot and how many of us did't swithch on air condition? How much gasoline need average American car? I think way too much but I still cant change that....
About 723 I agree with you. I like it and I use it....but sadly for many people more than 3 robust legs represent real problem. They are not able to construct pcb and so on. Some of them use that nasty soldering gun....everything is conected ,,in the air,, using wires and it is working only till first leg fall of from somewhere...so for those people 317 is probably batter or at least easier choice.
Oh btw do you need some...
Cheers
I agree with you completely and I'm using old components only for tests in the middle of the night when everything else is closed. I also agree with you that cheapest way to diy something is to buy it. But most of other people don't. There is a lot young guys around and also a lot from other parts of the world and many of them can't just go and buy new transformer. In quite few cases is even 10e problem so they recycle. It is not green I agree but we can't stop them. This summer has been hot and how many of us did't swithch on air condition? How much gasoline need average American car? I think way too much but I still cant change that....
About 723 I agree with you. I like it and I use it....but sadly for many people more than 3 robust legs represent real problem. They are not able to construct pcb and so on. Some of them use that nasty soldering gun....everything is conected ,,in the air,, using wires and it is working only till first leg fall of from somewhere...so for those people 317 is probably batter or at least easier choice.
Oh btw do you need some...
Cheers
Attachments
Ah ..one more thing Jean-Paul
Smps..I agree with you but if someone wan something very modern very in and very new....even expensive because we don't want to save money and than build it in very nice and expensive enclosure...than go for smps...
If not than our lovely 723 might be good choice. I like 723 anyway and I will stick to it.
Cheers
Smps..I agree with you but if someone wan something very modern very in and very new....even expensive because we don't want to save money and than build it in very nice and expensive enclosure...than go for smps...
If not than our lovely 723 might be good choice. I like 723 anyway and I will stick to it.
Cheers
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