As it seems necessary to indicate how things could/should be done here it is: the Build thread for the SBT PSU. Please use good old fashioned quality brand 60/40 leaded solder for best results and use a soldering iron that is designed to solder electronics. After the board is soldered it needs to be cleaned with isopropyl alcohol. Keep a set of pliers and a sharp side cutter on the work bench. Have a last look at the possibly revised BOM and check if you have all parts:
https://docs.google.com/spreadsheets/d/1p_VUbehXEywywlAYSOZgWKK46EWt7hKsMMJXMicOdNw/edit?usp=sharing
First solder SMD parts. Start with C9, C10, C8, R7, C3, C6 and C7. Then solder the common mode coils L1 and L2. Please note that these are very hard to solder when you do these last.
https://docs.google.com/spreadsheets/d/1p_VUbehXEywywlAYSOZgWKK46EWt7hKsMMJXMicOdNw/edit?usp=sharing
First solder SMD parts. Start with C9, C10, C8, R7, C3, C6 and C7. Then solder the common mode coils L1 and L2. Please note that these are very hard to solder when you do these last.
Attachments
Last edited:
Coil ready to be soldered. When these are soldered on the PCB please solder diode D1, D2, D3 and D4. Note how a few mm distance is kept from the PCB. This avoids heating up of the diode and the board. Schottky diodes like to be cool. It looks good and is somewhat better to use some solder on the upper side of the PCB too to solder the diodes. Don't overheat them.
After the coils you can solder C4, C5, X4, F1 etc.
After the coils you can solder C4, C5, X4, F1 etc.
Attachments
Last edited:
OK, a mockup (as I am waiting for IC1) with the right heatsink just waiting for IC1. You can see I like Panasonic TS-UP. You can use the 16V version if the 25V version is difficult to obtain (with 6V AC transformers that is). All MKDSN connectors can be soldered, just like C2. I prefer a little silicone for electronics to "glue" the large filter cap to the board but it is not 100% necessary, it is just a good habit. Now solder the heatsink to the board. Press it a little so that is is mounted upright.
*Please apply some heatsink paste to IC1 just below the mounting hole (in the middle of the chip) to make sure optimal heat transfer is done. Don't us too much as you see in 99% of cases. You just need a very little amount of it. It just serves to fill irregularities so small air gaps between heatsink and chip. Use an M3 screw, washer and nut to secure IC1 to the heatsink. When you see much excess heatsink paste coming at the sides you just know you used too much. The washer and nut go at the back of the heatsink. Tighten the screw. If this is done please cut off excess lead wires and then solder the 5 pins of IC1. This is the only right way as it will avoid mechanical stress on the pin to PCB connections. We like stuff that does not break down don't we ? 🙂
*Please apply some heatsink paste to IC1 just below the mounting hole (in the middle of the chip) to make sure optimal heat transfer is done. Don't us too much as you see in 99% of cases. You just need a very little amount of it. It just serves to fill irregularities so small air gaps between heatsink and chip. Use an M3 screw, washer and nut to secure IC1 to the heatsink. When you see much excess heatsink paste coming at the sides you just know you used too much. The washer and nut go at the back of the heatsink. Tighten the screw. If this is done please cut off excess lead wires and then solder the 5 pins of IC1. This is the only right way as it will avoid mechanical stress on the pin to PCB connections. We like stuff that does not break down don't we ? 🙂
Attachments
Last edited:
Ok, now imagine the board to be finished. Visually check orientation of diodes and caps another time as this is your last chance. Tantalum caps have their + indicated, it is easy to oversee this as it really is contradictory when all other caps have the - indicated but it is like it is. Clean the board and remove flux with isopropyl alcohol and cotton tabs. Put the board at your side and fetch the Rcore transformer.
Have a look at the wires. As can be seen from the diagram that is printed on the Rcore transformer you will need to connect some wires the right way for your specific mains voltage.
- Connections for 230V mains voltage: connect yellow to green and use black and red for L and N.
- Connections for 115V mains voltage (I know some Rcores slipped to 115V areas 😉): connect red to green. Then connect yellow to black. Here you have L and N.
Now I just ask you how to do this safely. But how ? Please post your view on this.
Have a look at the wires. As can be seen from the diagram that is printed on the Rcore transformer you will need to connect some wires the right way for your specific mains voltage.
- Connections for 230V mains voltage: connect yellow to green and use black and red for L and N.
- Connections for 115V mains voltage (I know some Rcores slipped to 115V areas 😉): connect red to green. Then connect yellow to black. Here you have L and N.
Now I just ask you how to do this safely. But how ? Please post your view on this.
Attachments
Last edited:
Regarding soldering of through hole parts: always first cut off excess wire and then solder for a way more reliable and better looking joint. This way you can not pull or push the lead wire and thus you will be avoiding mechanical stress on joints. Also when cutting you would put stress on the connections just by the cutting alone as the side cutter will push the wires when cutting. PCB material also loves this approach as you won't strip the tracks off the board. Last bonus is that the copper wire will be fully covered in solder which corrodes much less easy than copper. So just do it the right way and have reliable electronic DIY stuff. Hallelujah !
Last edited:
OK I had different plans for today but the alternative transformer Triad VPS10-2500 needed to be tested. I am out of low resistance load resistors but with 2A load there is still 6,5V (lowest point of ripple voltage at input of IC1) @ 225 V mains voltage. Filter cap is a 10,000 µF 25V Panasonic TS-UP. I wish I could do it right at once but I lack the right resistors right now. So preliminary conclusion is that just a Squeezebox Touch + USB stick or SD card connected to the "SBT PSU with Triad VPS10-2500" won't be a problem at all.
*Please note that the secondary windings of the Triad have to be connected in parallel ! Primaries need to be connected in series for 230V mains voltage areas. For 115V mains voltage areas both primary windings must be connected in parallel. Please see the datasheet.
http://www.onlinecomponents.com/datasheet/vps102500.aspx?p=12696738
For the Rcore transformer buyers there is no concern or any doubt as these were thoroughly tested for months. The Rcore transformer put out somewhat more than 6,5V under load so the margins are just fine.
*Please note that the secondary windings of the Triad have to be connected in parallel ! Primaries need to be connected in series for 230V mains voltage areas. For 115V mains voltage areas both primary windings must be connected in parallel. Please see the datasheet.
http://www.onlinecomponents.com/datasheet/vps102500.aspx?p=12696738
For the Rcore transformer buyers there is no concern or any doubt as these were thoroughly tested for months. The Rcore transformer put out somewhat more than 6,5V under load so the margins are just fine.
Last edited:
Go J-P, Go!
We are here. In my case, just absorbing, reading, thinking... These activities take a lot of time.
Jac
PS Good preliminary news on the Triad. Nothing I am building will take more than 2 Amps, so it's looking good. Thanks.
We are here. In my case, just absorbing, reading, thinking... These activities take a lot of time.
Jac
PS Good preliminary news on the Triad. Nothing I am building will take more than 2 Amps, so it's looking good. Thanks.
You should know how much time I put in these projects 😱 Do you think the "online build manual" aka this thread is sufficient ?
I also built a 22,000 µF version specifically for use with the Triad (5A rated so current in abundance) in 115V mains voltage areas to make margins larger but I did not like the outcome. Ripple became lower as intended but the diodes got hot. Note that the diodes are 5A types. Anyway you can't say I forgot the American builders 😉 Anyway I can only encourage to use 10,000 µF caps.
Today I learnt that Panasonic TS-UP 10,000 µF 25V is out of production so get it while you can. It is one of the better caps out there for this purpose.
I also built a 22,000 µF version specifically for use with the Triad (5A rated so current in abundance) in 115V mains voltage areas to make margins larger but I did not like the outcome. Ripple became lower as intended but the diodes got hot. Note that the diodes are 5A types. Anyway you can't say I forgot the American builders 😉 Anyway I can only encourage to use 10,000 µF caps.
Today I learnt that Panasonic TS-UP 10,000 µF 25V is out of production so get it while you can. It is one of the better caps out there for this purpose.
Last edited:
Prototype with Ampère meter but without without Ampère meter connector (board will be replaced with the V5.3 production version) just to show a reasonable OK layout in a plain too small case. Note the near unregulatory short distance between 230V carrying fuse holder and transformer core. This is called a prototype for a reason, it just serves to show a layout in a case. Of course this case has a slotted cover for cooling. I will be away for some days hence me posting this information. I probably can't answer questions the following days.
As you can see it has benefits to keep both mains and DC cabling at the back but both at opposite sides. No hum, no cable clutter etc. Also note the mains voltage fuse holder which is mandatory and therefore it has been added to the BOM. Cable glands are used to protect the device against pulling of cables. Power switch is added because, although it is an always on device, a human being has to go out once in a while. Of course the board can be turned 180 degrees so that 230V mains and DC cabling can be swapped in case you like that better. Both the power switch and Ampère meter have to be swapped as well in that case. Always carefully plan your layout, best is to do this with an unpopulated PCB and the transformer in the new case. Just move the PCB and transformer and the parts so that you get an optimal situation. Try not to scratch the PCB. Keep some distance between transformer and PCB. Mark all drillings, drill the holes and fit connectors, cable glands to see if they are located OK. Then remove cable glands etc. and sand the (re-used) case with number 600 or 800 sanding paper, clean it and degrease it, spray it in primer and apply the final paint layer in a few thin layers. Leave it drying overnight for best results. This specific case is an old DDR car battery charger that is being re-used.
PE is connected to the case and the transformer bracket. Output GND is kept floating as I always do. This is fully legal here and it saves some hum solving. Check your local regulations and adapt to them.
As you can see it has benefits to keep both mains and DC cabling at the back but both at opposite sides. No hum, no cable clutter etc. Also note the mains voltage fuse holder which is mandatory and therefore it has been added to the BOM. Cable glands are used to protect the device against pulling of cables. Power switch is added because, although it is an always on device, a human being has to go out once in a while. Of course the board can be turned 180 degrees so that 230V mains and DC cabling can be swapped in case you like that better. Both the power switch and Ampère meter have to be swapped as well in that case. Always carefully plan your layout, best is to do this with an unpopulated PCB and the transformer in the new case. Just move the PCB and transformer and the parts so that you get an optimal situation. Try not to scratch the PCB. Keep some distance between transformer and PCB. Mark all drillings, drill the holes and fit connectors, cable glands to see if they are located OK. Then remove cable glands etc. and sand the (re-used) case with number 600 or 800 sanding paper, clean it and degrease it, spray it in primer and apply the final paint layer in a few thin layers. Leave it drying overnight for best results. This specific case is an old DDR car battery charger that is being re-used.
PE is connected to the case and the transformer bracket. Output GND is kept floating as I always do. This is fully legal here and it saves some hum solving. Check your local regulations and adapt to them.
Attachments
Last edited:
Yes, publishing them feels wrong so I won't. Let's say noise is quite low. You can find some experiences in this thread:
http://www.diyaudio.com/forums/group-buys/264185-squeezebox-touch-psu-7.html
Last edited:
We intended to but we got the word it will be on Ebay anytime soon. I can't prevent that but I am reluctant to publish the schematic. You see, I am supporting stuff and put my time in it. Is it really necessary to have it ? A photo of the board with connections together with the BOM should be enough to finish this project. Let me know. It is not a complicated device but it is the combination of things that make it a good PSU. "Follow the BOM" is a sound advice to have optimal results.
For these reasons my new project will be done differently. Possibly also a bit faster 🙂
For these reasons my new project will be done differently. Possibly also a bit faster 🙂
Last edited:
In case people don't know the different Squeezebox designs, there is the Classic, the Duet (aka the Receiver), and the Touch. The Classic and the Touch use a 5v power supply which is consistent with JP's design. The Duet uses a 9v supply so it will need a different transformer and some of the parts will need to be changed to support 9v. In the other thread, someone asked about the connectors to the Squeezebox. Here are their physical dimensions in case you need to order connectors.
Classic:
2.5mm ID, 5.5mm OD, 11mm long
Duet:
1.05mm ID, 3.5mm OD, 7mm long
The Touch uses the same connector as the Classic.
---Gary
Off topic alarm 🙂 : for a Duet one needs to buy a 9V transformer, I have no experience with the Duet but it seems to draw max. 600 mA. I think you will be safe with a 9V 2A transformer. R5 (or R6 when SMD resistors are used) needs to be changed for 9V output. Please check the datasheet of the LT1764A. I would use a 4700 µF 25V snap in cap for C2. I think all the parts are rated for 9V AC/13V DC use as well. It can be wise to adjust R8 for a slightly dimmed LED. (UBat - Uf LED)/Iled = Rseries. I use 2 mA for standard green 3 mm LEDs. There already is a 3k24 resistor in the BOM which you might want to use for the LED 😉 (must be SMD 0805).
You could try out a 15VA Amplimo 08011 with 2 x 9V 0.83A in parallel. It should work fine. As we're audiophiles/audiofools a more beefy transformer seems to be a must but it will cost you space and money. An Rcore transformer is also available in 2 x 9V:
http://www.ebay.com/itm/115V-230V-3...855?pt=LH_DefaultDomain_0&hash=item463d159b17
You could try out a 15VA Amplimo 08011 with 2 x 9V 0.83A in parallel. It should work fine. As we're audiophiles/audiofools a more beefy transformer seems to be a must but it will cost you space and money. An Rcore transformer is also available in 2 x 9V:
http://www.ebay.com/itm/115V-230V-3...855?pt=LH_DefaultDomain_0&hash=item463d159b17
Last edited:
Unfortunately, you have stated this accurately. As far as I'm concerned, don't publish the schematic. I have all the information I need.
Jac
For those not handy with a calculator, please change R5 (or R6) to 1.58K or 1.62K. Using 1.62K will give slightly under 9v and 1.58K will give slightly over 9v. The exact voltage isn't too critical since the Duet regulates most of the internal voltages from the external supply.
---Gary
- Status
- Not open for further replies.