ichiban,
SMD parts really are the best parts for job in this case, which is why I chose to use them. It helps minimize signal path length and makes for a better layout. The decoupling caps on the top layer that return to the ground plan are the shiznit when it comes to performance.
They're actually much quicker and easier to solder than PTH parts, but just the same, I can solder up all the SMD parts on your board before I send them out to you. Several of the parts might be arranged as a group buy anyhow, so I'll probably have most of them here anyhow.
I'll send along a spare section of an old PCB and some 0805 resistors you can practice on. Once you get the hang of it, it's about 3 times quicker than doing PTH.
Cheers,
Owen
SMD parts really are the best parts for job in this case, which is why I chose to use them. It helps minimize signal path length and makes for a better layout. The decoupling caps on the top layer that return to the ground plan are the shiznit when it comes to performance.
They're actually much quicker and easier to solder than PTH parts, but just the same, I can solder up all the SMD parts on your board before I send them out to you. Several of the parts might be arranged as a group buy anyhow, so I'll probably have most of them here anyhow.
I'll send along a spare section of an old PCB and some 0805 resistors you can practice on. Once you get the hang of it, it's about 3 times quicker than doing PTH.
Cheers,
Owen
Can anyone suggest some "Audiophile" grade linear regs that could be used in place of the LM317/337?
I'm just making the BOM now, and if people feel like spending more on these, then I'd like to give them the option. I need a Vin of 60V Vout of up to 50V and at least 250mA of current capability.
I have heard great things about the Salas regs, but they're fully discrete and it would mean that I would have to design them in, order parts, test the circuit, and then redo the layout for them. All of that takes time, and I like to get these board out the door.
qusp:
You seem like the type of guy who like regs... what are you planning to use in place of the LM317/337?
Cheers,
Owen
I'm just making the BOM now, and if people feel like spending more on these, then I'd like to give them the option. I need a Vin of 60V Vout of up to 50V and at least 250mA of current capability.
I have heard great things about the Salas regs, but they're fully discrete and it would mean that I would have to design them in, order parts, test the circuit, and then redo the layout for them. All of that takes time, and I like to get these board out the door.
qusp:
You seem like the type of guy who like regs... what are you planning to use in place of the LM317/337?
Cheers,
Owen
yeah I was going to suggest the ohmite thin film power R's, COG/NPO caps and thin film R's (if any) for a GB. sure mate I can suggest some regs, in fact I can suggest some that might mean I can use them as they are SMD too. linear tech are IMO world leaders at the moment in the IC reg area. give me a minute i'll dig up some datasheets
The most obvious option is the LT317/337 which are supposed to be drop in replacements. See also this thread Where the LT1085 and LT1033 are briefly discussed.
Ichiban:
Start with a pair of clean pads, and then melt a little solder on one of the two ("tin it" if you will) get some decent tweezers, and hold the part with them and position it in front of the tinned pad.
Melt the solder and push the component into the molten solder while making sure it's flat on the board and centered on the pads. Let that side cool, then solder the other side without over-heating the component, and it'll stay right where it is. I usually go back after that, and clean up the first solder joint with a little more solder. That will give you two nice joints, and going back helps to ensure you don't have any cold joints.
qusp:
I'm using one Caddock and one Ohmite thin film right now, since the Ohmites aren't available in the 200R value. I like the specs on the Ohmite, but the absurd leads and lack of a mounting hole are getting on my nerves. I've honestly tried to bend the leads with all of my strength and they won't budge. I have no idea what they're made out of, but it's not copper.
I agree with your other suggestions though... I should have a BOM ready pretty soon.
Owen
Start with a pair of clean pads, and then melt a little solder on one of the two ("tin it" if you will) get some decent tweezers, and hold the part with them and position it in front of the tinned pad.
Melt the solder and push the component into the molten solder while making sure it's flat on the board and centered on the pads. Let that side cool, then solder the other side without over-heating the component, and it'll stay right where it is. I usually go back after that, and clean up the first solder joint with a little more solder. That will give you two nice joints, and going back helps to ensure you don't have any cold joints.
qusp:
I'm using one Caddock and one Ohmite thin film right now, since the Ohmites aren't available in the 200R value. I like the specs on the Ohmite, but the absurd leads and lack of a mounting hole are getting on my nerves. I've honestly tried to bend the leads with all of my strength and they won't budge. I have no idea what they're made out of, but it's not copper.
I agree with your other suggestions though... I should have a BOM ready pretty soon.
Owen
but in answer to your question, i'm using the coffin minigold dual, which is a HV capable bipolar jung type super reg. but just having a look for something for you now. only limiting factor is the voltage, I know of plenty of excellent replacements for them at up to 35v, but above that it becomes a bit scarce.
AFAIK LT1083/33 arent capable of that input/output V Jacques. I know the linear tech catalogue pretty well as i've been spending quite a bit of time there lately, but these specs are limiting, i'll find something though. yeah owen I had seen you were using one of each and had noticed the lack of a 200R which is a bit odd. dont they also come in SMD though? and then could use the SMD for the lower wattage part and the caddock for the higher wattage.
depending on the BOM values, the vishay Zfoil SMD might be suitable for the smaller (not power) ones haha. but thats just silly.
not having much luck at linear; all of the higher V parts are soic16 with ground pad underneath, or DFN type packages. 30-35v is about where the rest start topping out
depending on the BOM values, the vishay Zfoil SMD might be suitable for the smaller (not power) ones haha. but thats just silly.
not having much luck at linear; all of the higher V parts are soic16 with ground pad underneath, or DFN type packages. 30-35v is about where the rest start topping out
Last edited:
right, yep, Jacques yopu were on the money. not the LT317/337, go with the LT1085 and LT1033. both of these can be used in a similar floating manner, so the Vin/Vout doesnt matter so much. so you could go with the LT1083 in this instance as we dont need that much current and the 1033 is the complimentary. I have used these before with very good results for their type. the max Vin is only like 35 or something, but there is no ground pin
the rest are either too hard to solder for the average hobbiest, or have a ground pin that is used for adjustment or sense. also the size of the transformer could be smaller with these, because they are LDO regs
the rest are either too hard to solder for the average hobbiest, or have a ground pin that is used for adjustment or sense. also the size of the transformer could be smaller with these, because they are LDO regs
Last edited:
oh I have them already, they are great regs and are definitely leagues ahead of the 317/337, I just wasnt thinking straight re floating and not being effected so much by the supply voltage as long as the input/output differential is not crazy high. there are much nicer regs from linear too that I have here, but none of them are suitable due to having a ground reference. thanks for reminding me of them though, I was determined to find something in their low noise range that would work, but nothing is suitable for a GB.
dunno about using it for both poles, interesting, will have a search for this post
dunno about using it for both poles, interesting, will have a search for this post
Last edited:
SMD resistors
SMD resistors low wattage:
Rs online:
+-10ppm 0.1% tolerance:
Panasonic 105 values 470R-100K
Tyco 888 values 2R-464K
Vishay 28 100R-1Meg
-----
Farnell:
+-0.01% tolerance
Vishay Dale 15 values
Vishay foil resistors 19 values
100R to 100K
-----
Mouser:
+-0.02% tolerance 5ppm
Susumu RG Series Ultra Precision Thin Film Chip Resistors values range from 100R to 10K
0.1% tol +-25ppm
Panasonic
47R to 1000K
-----
DigiKey:
+-5ppm +-0.02% tol
Susumu RG Series
100R to 20K
-----
That's about qualities shopping on line, when B.O.M. published with exact values I can see where are cheapest.
SMD resistors low wattage:
Rs online:
+-10ppm 0.1% tolerance:
Panasonic 105 values 470R-100K
Tyco 888 values 2R-464K
Vishay 28 100R-1Meg
-----
Farnell:
+-0.01% tolerance
Vishay Dale 15 values
Vishay foil resistors 19 values
100R to 100K
-----
Mouser:
+-0.02% tolerance 5ppm
Susumu RG Series Ultra Precision Thin Film Chip Resistors values range from 100R to 10K
0.1% tol +-25ppm
Panasonic
47R to 1000K
-----
DigiKey:
+-5ppm +-0.02% tol
Susumu RG Series
100R to 20K
-----
That's about qualities shopping on line, when B.O.M. published with exact values I can see where are cheapest.
Last edited:
forget farnell and RS, both are ripoff!! sumumu are def my favorite thin film and mouser has a good range of them in stock. I prefer mouser mainly because of the free international fedex 2 day shipping after 200 dollar order 
. of course there is the SMD zfoil range, but they are like 14 dollars a pop, though I still may choose 1 or 2 positions worthy of them just because. of course I just made a 400 dollar order with mouser yesterday, but I usually make a regular order every 2 weeks; hows that BOM going Owen?
. of course there is the SMD zfoil range, but they are like 14 dollars a pop, though I still may choose 1 or 2 positions worthy of them just because. of course I just made a 400 dollar order with mouser yesterday, but I usually make a regular order every 2 weeks; hows that BOM going Owen?
aha, yeah center tap, not always doable. funny thing, I just checked the mouser catalogue for the smd ZFOIL and they want 53aud each lol. better off getting a GB together and contacting them directly. its not supposed to be soldered by hand either due to the dielectric being easily scratched with tweezers, but a steady hand and quick action its no problem
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.