Universal LM317 Adapter Board

[batteryman]

The adjustable LM350T has a 3a capability (heatsinked). Quite low noise too @ 0.001%

A LT1033 is a negative version.

 

[Ghoostknight]

The adjustable LM350T has a 3a capability (heatsinked). Quite low noise too @ 0.001%

this is kind of a LM317 sucessor right? seems pin combatible

the LT1083/LT1084/LT1085 also look interesting and was recommended they can regulate up to 7,5A..

i was able to cancel this pcb from my order ... the usb ground filter and dc smoothing board is now in production

i looked into filtering noise but im unsure wether i really need it in my application, filters seem mostly just recommended for switching power supplies?
i made a simple version now without the adj circuit, simple sparkos design but currently still without any filter... since im not an expert in designing a filter i might better make external boards that can be hooked up between the dc smoothing board and the sparkos adapter

or maybe test something like this: https://www.aliexpress.us/item/1005003489409213.html ?
or this: https://de.aliexpress.com/item/1005005438659005.html

the 2,54mm pinheaders are rated at 3A .. tho im not sure if this rating is voltage independent... but i was thinking.... for my own regulators i could double up the pins.... the design would be still combatible with sparkos and others since you just use one row of the header instead of two... but doubling the pins up gives better contact resistance... the regulators probably sit more stable in the socket because it has 2 rows... and better current handling, if we go with a semi-optimal socketed design why not improve it?

 

[Ghoostknight]

hmm the person who told me about the ifi idefender circuit also recommended to use panasonic oscon caps to filter out noise, back then it was about a raspberry pi system, he said i could just slap banks of oscon caps on the power rails to improve things... back then i bought around 70 470uF oscon caps

how about slapping 2-4 470uF caps on the input as a filter?

 

[Ghoostknight]

i searched the oscons, they are SEPC series, i think i selected them for low ESR, tho the ones i have here are just rated at 16V ... i might still try them, the majority of regulators will run at 5V or below...

 

[batteryman]

this is kind of a LM317 sucessor right? seems pin combatible

the LT1083/LT1084/LT1085 also look interesting and was recommended they can regulate up to 7,5A..

i was able to cancel this pcb from my order ... the usb ground filter and dc smoothing board is now in production

i looked into filtering noise but im unsure wether i really need it in my application, filters seem mostly just recommended for switching power supplies?
i made a simple version now without the adj circuit, simple sparkos design but currently still without any filter... since im not an expert in designing a filter i might better make external boards that can be hooked up between the dc smoothing board and the sparkos adapter

or maybe test something like this: https://www.aliexpress.us/item/1005003489409213.html ?
or this: https://de.aliexpress.com/item/1005005438659005.html

the 2,54mm pinheaders are rated at 3A .. tho im not sure if this rating is voltage independent... but i was thinking.... for my own regulators i could double up the pins.... the design would be still combatible with sparkos and others since you just use one row of the header instead of two... but doubling the pins up gives better contact resistance... the regulators probably sit more stable in the socket because it has 2 rows... and better current handling, if we go with a semi-optimal socketed design why not improve it?

Those Aliexpress LC filters are worth testing but if they are not common mode, not as good if using an isolated input.
Also, the inductors look to be 100uH whereas I use 33-50mH which offer usefull fitering down to 10kHz.

The sellers should provide a graph of the response otherwise how do you know whether it's going to be much use?

Yes the Panasonic caps I used were Oscons (couldn't remeber the name earlier) but LC filters must be a better way I feel.

 

[Ghoostknight]

Those Aliexpress LC filters are worth testing but if they are not common mode, not as good if using an isolated input.
Also, the inductors look to be 100uH whereas I use 33-50mH which offer usefull fitering down to 10kHz.

The sellers should provide a graph of the response otherwise how do you know whether it's going to be much use?

Yes the Panasonic caps I used were Oscons (couldn't remeber the name earlier) but LC filters must be a better way I feel.

hmm

this is how it currently looks:

3 input caps + bypass, 1 output cap
caps are 100uF since they need rated to be rated for 50V if you wanna have some margin with 20-30V.. i will test 16V 470uF SEPC oscons in this position too since i mostly need under 10V

Also since its probably best to always have caps at the "destination" it makes sense to insert more input capacitance than output caps

i might test filters in a seperate aliexpress board style i think as long im unsure wether they make things better or worse..

together with this goes this regulator:

(mind the 6pin pinheader instead of 3 pin.., sparkos and similar ones can be still used with no problem)

 

[batteryman]

That's fine for your own use but not sure there'd be much interest from other members because:

Not easy to use a heatsink
No On board bridge rectifier and main smoothing cap,
For me, no CMC choke option.

https://www.ebay.co.uk/itm/266390421688

 

[Ghoostknight]

Not easy to use a heatsink

if you wanna use heatsinked regulators you have to put them with the heatsink on the regulator dauther board, since the pinout now (GND/OUT/IN and GND/IN/OUT for negative regulator) isnt combatible with for example the LM317, its now purely a universal "baseplate" for some regulators...

you can still put a heatsink on the regulator board, there is no point with this pinout to offer heatsink option on PCB

im still looking for a higher ampere regulator, so i might make one with heatsink in the future but as you see the baseplate is fairly small with not much clearance to the screw terminals... you got 24mm in between, sparkos should fit just fine

No On board bridge rectifier and main smoothing cap,

i made another board for this, i could make it a combine board but then i would still need this baseplate here to run regulators seperately, i find it kinda more appealing todo it in seperate boards, lets you easly exchange just part of the design, tho i agree a rectifier/smoothing/regulator board could be done too, i have to see, i just added a fuse and multiple wima capacitor footprints to the rectifier board

For me, no CMC choke option.

like i said, as im unsure how it affects things i rather let it out and do it on a seperate board, so i dont have to redesign a "all in one" board 5 times, but just redesign the specific kinda "universal" board, is there something wrong with this aproach? i dont think cables between boards matter that much

 

[Ghoostknight]

That's fine for your own use but not sure there'd be much interest from other members because:

i mainly design these boards for myself, i just share them here to get ideas and maybe someone else is interested too

 

[batteryman]

There's nothing wrong with what you have designed if it works for you but for under £5 and a 3week wait, you can get one of the ebay ones.

Th cmc choke option is for when a wallwart smps is used as the raw DC supply otherwise not needed.

I appeciate it's good to design your own pcbs - I've done many covering a wide range of devices but if I was to make one which I thought might appeal to others, I'd give it features not found in other similar products. If I used SMD devices I'd use the LT3042 (0.8uv RMS noise, 79db PSRR)

 

[Ghoostknight]

Ah yea, well you kinda know what you got if you made it your own instead of china pcbs

i just choose the TPS regulator for now since they are available for cheap at lcsc.com (the supplier of jlcpcb) and are close with 4uV noise and offer 1A instead of 200/500mA, the LT3042 and LT3045 seem a bit pricier and not as available

I've done many covering a wide range of devices but if I was to make one which I thought might appeal to others, I'd give it features not found in other similar products.

the title of the thread if badly picked, but the use case is to have something universal (not necessarly LM317), that can accept sparkos and the other available regulators in LM317style like the ldvor.com ones
something like this doesnt exist on ebay or aliexpress, you always need to modify some LM317 circuit todo it, so imo its still a special usecase, basicly its now just a base board with "more specialized" socket to accept any regulator you want if you make it on a daugtherboard and you can easly swap regulators in and out

tho i might think about adding a regulator socket to the rectifier board, the thing that holded me kinda back was uncertainty if i wanna use multiple regulators but with the new 6 pin socket i can easly do daughterboards that fit multiple regulators (as long the current base plate design has enough clearance for it since i still will need it, i might make it 32mm)

about the CMC choke, well i never intend to use a SMPS... so im kinda unsure about it since i havent tried filters yet, this stuff is fairly new, i know my way around 230V stuff and a bit of knowledge here and there but im by no means a pro or something like that..

 

[batteryman]

I took a chance and bought three of these TPS regulators for a good price to provide a very clean +5v for a R2R DAC. (raw supply is from my Li-Ion battery module.)

https://www.aliexpress.com/item/1005005892731807.htm

I used a 50mh 3a CMC to clean up a 19v laptop psu which I use to provide 14v for a pair of PCC88 heater in series. It made a measureable difference.

 

[Ghoostknight]

you forgot a "L" -> https://de.aliexpress.com/item/1005005892731807.html

Can you tell me what position they use the tantalum cap in?
Did you hear a difference between regulators? how does the TPS compare? i guess you like the LT3042 more? (even with transistor output?)

 

[batteryman]

The Tant is on the output as per the datasheet.

I haven't used it yet. I doubt I'll be able to hear any difference but the price was good compared to many sellers using the same chip or the 3042.
Also came with a stick on heatsink and metal screen.

 

[Ghoostknight]

ah i ask because the datasheet states this:
"Regulator output. A capacitor greater than or equal to 10 μF must be tied from this pin to
ground to assure stability. A 47-μF ceramic output capacitor is highly recommended to be
OUT 1, 20 O connected from OUT to GND (as close to the device as possible) to maximize ac
performance"

I haven't used it yet. I doubt I'll be able to hear any difference but the price was good compared to many sellers using the same chip or the 3042.
Also came with a stick on heatsink and metal screen.

never compared regulators so im just curious

BOM is around 3-4 dollars i think for the regulator i made, possibly in the 6-8 dollar range after i let jlcpcm assemble the boards, tho this quickly adds up if i would buy ldvor regulators for 20 dollars.. the big pro is i can use murata caps instead of some nobrand ones on chinese boards so i atleast know what i got for 8 dollar