11 of the 12 PCBs are now spoken for.
Let's see how my testing goes next week. If there is more interest I can always order more boards.
My BOM (only the first 6 lines are SMD/included/populated):
LT3062EMS8E#PBF Linear Technology IC REG LDO ADJ 0.2A 8MSOP
CRCW1206100KFKEA Vishay Thick Film Resistors - SMD 1206 1/4watt 100Kohms 1%
GRM3195C1H103JA01D Murata MLCC - SMD/SMT 1206 0.01uF 50volts 85C C0G 5%
GRM31CR61H106MA12L Murata MLCC - SMD/SMT 1206 10uF 50volts 85C X5R 20%
GRM31MR71H105KA88K Murata MLCC - SMD/SMT 1206 1.0uF 50volts 85C 10%
DF04S-G Comchip Technology Bridge Rectifiers DFS GPP 1A 400V Rect. Bridge Diode
EEU-FC1J102 Panasonic Aluminum Electrolytic Capacitors - Leaded 1000uF 63V 105C
EEU-FC1J101L Panasonic Aluminum Electrolytic Capacitors - Leaded 100uF 63V 105C
3296Y-1-503LF Bourns Trimmer Resistors - 50Kohms Sealed Vertical Adjust
37203150411 Littelfuse Fuses with Leads (Through Hole) IEC TL LBC SL .315A TR5
56000001009 Littelfuse Fuse Holder 6.3A/1.6W/4.3mm TR5/TE5 Holder
3FD-456 Tamura Power Transformers 6VA 28V@0.22A 56V@0.11A
BK
Let's see how my testing goes next week. If there is more interest I can always order more boards.
My BOM (only the first 6 lines are SMD/included/populated):
LT3062EMS8E#PBF Linear Technology IC REG LDO ADJ 0.2A 8MSOP
CRCW1206100KFKEA Vishay Thick Film Resistors - SMD 1206 1/4watt 100Kohms 1%
GRM3195C1H103JA01D Murata MLCC - SMD/SMT 1206 0.01uF 50volts 85C C0G 5%
GRM31CR61H106MA12L Murata MLCC - SMD/SMT 1206 10uF 50volts 85C X5R 20%
GRM31MR71H105KA88K Murata MLCC - SMD/SMT 1206 1.0uF 50volts 85C 10%
DF04S-G Comchip Technology Bridge Rectifiers DFS GPP 1A 400V Rect. Bridge Diode
EEU-FC1J102 Panasonic Aluminum Electrolytic Capacitors - Leaded 1000uF 63V 105C
EEU-FC1J101L Panasonic Aluminum Electrolytic Capacitors - Leaded 100uF 63V 105C
3296Y-1-503LF Bourns Trimmer Resistors - 50Kohms Sealed Vertical Adjust
37203150411 Littelfuse Fuses with Leads (Through Hole) IEC TL LBC SL .315A TR5
56000001009 Littelfuse Fuse Holder 6.3A/1.6W/4.3mm TR5/TE5 Holder
3FD-456 Tamura Power Transformers 6VA 28V@0.22A 56V@0.11A
BK
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Good job researching the part numbers BK.
Obviously, if someone is going to using the supply with lower voltages like myself, they could use say 35VDC 'lytics and a lower voltage transformer.
Obviously, if someone is going to using the supply with lower voltages like myself, they could use say 35VDC 'lytics and a lower voltage transformer.
Well Rudi, what's the verdict? Will a 2x12VAC do the job, or not?
I don't see any reason why that voltage transformer will not work since there will be roughly 16.8VDC after rectification going to the LT3062 regulators.
That should be more than enough voltage for these LDO regulators and even enough for the LM317/337 regulators.
Thanks Rudi!
Ammel, I have received and installed the ordered EI38-12VAC transformer, manufactured by HAHN, having 2 secondary 12VAC windings @ 2.25VA each, today and have measured.
Both +/-12VDC and +/-15VDC can be easily adjusted with this transformer.
The proposed 50K potentiometer for adjustment showed a value of about 4.05KOhm, after I have unsoldered it.
Maybe it would be wise to use a 10KOhm potentiometer (instead of the 50KOhm), if you want to adjust the LT3062 to "low" voltages and like it "smooth".
Best regards - Rudi_Ratlos
Both +/-12VDC and +/-15VDC can be easily adjusted with this transformer.
The proposed 50K potentiometer for adjustment showed a value of about 4.05KOhm, after I have unsoldered it.
Maybe it would be wise to use a 10KOhm potentiometer (instead of the 50KOhm), if you want to adjust the LT3062 to "low" voltages and like it "smooth".
Best regards - Rudi_Ratlos
Thank you Rudi for all your hard work!
I'll order the dual 12VAC Tamura transformer I linked to earlier from Mouser and use 10k trimmers instead of 50k. Yes, I prefer "smooth" voltage adjustments.
I'll order the dual 12VAC Tamura transformer I linked to earlier from Mouser and use 10k trimmers instead of 50k. Yes, I prefer "smooth" voltage adjustments.
Built up two boards and everything checks out, so I consider this batch proved.
I have them adjusted for 37V, but could easily get to ~40V. The Tamura transformer is putting out 33VAC on the secondaries (unloaded) with my 115VAC paralleled primaries.
The other two boards shown are what I can provide to folks - smd parts installed by stencil/reflow. These particular boards are for Rudi.
BK
I have them adjusted for 37V, but could easily get to ~40V. The Tamura transformer is putting out 33VAC on the secondaries (unloaded) with my 115VAC paralleled primaries.
The other two boards shown are what I can provide to folks - smd parts installed by stencil/reflow. These particular boards are for Rudi.
BK
Attachments
Nice work BK.
I'm still NOT clear on how to use a single board as +/-(dual) supply.
I see clearly see GND1, V1, GND2, V2 on the output pads.
Is V1 the positive voltage or negative voltage?
Do you connect the GND1 and GND2 together for the ground?
I'm still NOT clear on how to use a single board as +/-(dual) supply.
I see clearly see GND1, V1, GND2, V2 on the output pads.
Is V1 the positive voltage or negative voltage?
Do you connect the GND1 and GND2 together for the ground?
Ammel: you can customize the PCB to provide two independent output voltages:VoltageV1 with GND1 and VoltageV2 with GND2.
This is one way to do it.
If you put a jumper cap on jumper JP, the jumper cap connects V1 and GND2. This connection can be considered as "common GND".
In this case V2 is a positive voltage, whereas GND1 is negative when compared to the "common GND".
You then have a "dual LT3062 +/- PSU".
Configuring the PCB as a "dual +/- PSU" works, as long as you are using a transformer with 2 independent secondaries.
Has my explanation been clear enough?
Best regards - Rudi_Ratlos
This is one way to do it.
If you put a jumper cap on jumper JP, the jumper cap connects V1 and GND2. This connection can be considered as "common GND".
In this case V2 is a positive voltage, whereas GND1 is negative when compared to the "common GND".
You then have a "dual LT3062 +/- PSU".
Configuring the PCB as a "dual +/- PSU" works, as long as you are using a transformer with 2 independent secondaries.
Has my explanation been clear enough?
Best regards - Rudi_Ratlos
Yes, that clears things up.
Thank you Rudi and BK.
BK, do you have a final price on the boards?
When do you think you'll start shipping them?
Thank you Rudi and BK.
BK, do you have a final price on the boards?
When do you think you'll start shipping them?
Figure ~10 days since I need to re-order components for this batch. Stay tuned on the total, but will be close to the former estimate. All at cost since this is being done as a courtesy and I'm not looking to make a profit.
BK
These are the updated costs on a per board basis:
- single PCB: $2.75
- all SMD components installed (see below): $12.19
- solder paste: $0.56
- stencil & jig = NA
Total excluding shipping = $15.50/board.
BK
LT3062EMS8E#PBF Linear Technology IC REG LDO ADJ 0.2A 8MSOP
CRCW1206100KFKEA Vishay Thick Film Resistors - SMD 1206 1/4watt 100Kohms 1%
GRM3195C1H103JA01D Murata MLCC - SMD/SMT 1206 0.01uF 50volts 85C C0G 5%
GRM31MR71H105KA88K Murata MLCC - SMD/SMT 1206 1.0uF 50volts 85C X7R 10%
GRM31CR61H106MA12L Murata MLCC - SMD/SMT 1206 10uF 50volts 85C X5R 20%
DF04S-G Comchip Technology Bridge Rectifiers DFS GPP 1A 400V Rect. Bridge Diode
- single PCB: $2.75
- all SMD components installed (see below): $12.19
- solder paste: $0.56
- stencil & jig = NA
Total excluding shipping = $15.50/board.
BK
LT3062EMS8E#PBF Linear Technology IC REG LDO ADJ 0.2A 8MSOP
CRCW1206100KFKEA Vishay Thick Film Resistors - SMD 1206 1/4watt 100Kohms 1%
GRM3195C1H103JA01D Murata MLCC - SMD/SMT 1206 0.01uF 50volts 85C C0G 5%
GRM31MR71H105KA88K Murata MLCC - SMD/SMT 1206 1.0uF 50volts 85C X7R 10%
GRM31CR61H106MA12L Murata MLCC - SMD/SMT 1206 10uF 50volts 85C X5R 20%
DF04S-G Comchip Technology Bridge Rectifiers DFS GPP 1A 400V Rect. Bridge Diode
All boards are reflowed, cleaned and ready to go. Will try to get them out soon.
Underside of the LT3062 is soldered to the PCB/ground plane.
On my fully built PS, I did some under-board connections to parallel the inputs for my 115V mains + Tamura (yellow wiring).
BK
Underside of the LT3062 is soldered to the PCB/ground plane.
On my fully built PS, I did some under-board connections to parallel the inputs for my 115V mains + Tamura (yellow wiring).
BK
Attachments
This is looking good. I have a stalled preamp project and these boards should get it back on track. Thank you for keeping 'us' in the loop.
...and yes, thanks for that little BOM with part numbers, as ammel68 pointed out. Very handy! Cheers.
...and yes, thanks for that little BOM with part numbers, as ammel68 pointed out. Very handy! Cheers.
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I spent some time yesterday load testing my own fully built boards at +/- 37V with a 1k ohm passive load on each side (aka, 37mA/side) and didn't uncover any issues. LT3062 heats up to just a few degrees over ambient via thermocouple measurements and with my new 400MHz 10-bit R&S scope I'm seeing 370uV Vp-p noise, which I believe is pretty much in the noise floor of the particular setup. I have to add a disclaimer that PS testing is an art and I am NO EXPERT by any stretch, so I'm not making any claims here - just verifying basic function and robustness. Lower Vout should measure even better. I think everyone will be happy with this very flexible little unit. Thanks to Rudi for the layout!
BK
BK
Hi BK, how much for a full kitt?, the through hole parts can be left unsoldered , I can do that, all smd needs to be on the board soldered, from what I can see one board can supply dual voltage,. By full kitt I mean transformer and everything or at least tell me what are the specs for the Tamura transformer that would allow me to replace it with something else.
Thanks,
Florin
Thanks,
Florin
Sorry outtek, but I'm out of boards. Might do another run this Fall with updated PCB.
All parts are detailed in a prior post.
Perhaps one of the initial GB participants can sell you an underutilized board?
BK
All parts are detailed in a prior post.
Perhaps one of the initial GB participants can sell you an underutilized board?
BK
Florin, you can at least start with the SYMASYMs backend PSU to drive the frontend!
I have taken a look at my "stock".
I offer you Mihais FC-100 shunt-regulator that will fit perfectly for 2 SYMASYM frontends for 1€ + shipping.
Tell me, if you like to have the PCB.
Best regards - Rudi
I have taken a look at my "stock".
I offer you Mihais FC-100 shunt-regulator that will fit perfectly for 2 SYMASYM frontends for 1€ + shipping.
Tell me, if you like to have the PCB.
Best regards - Rudi
Attachments
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