goldenreference low voltage power supply

*jamesmking* · July 6, 2020

On 7/4/2020 at 12:41 AM, bravi said:

Hi All,

Soldered the first lot of 4 pcbs of Sync rectifier with all components. Tested with 12 v transformer . Got around 16.1v on the output with a 10mF capacitor. With a test resistor load of 48ohms the current would have been around 330ma. Great start for me with learnings on soldering smd device.

Any views on the max current that can be drawn with this sync rectifier board without stressing the components?

Cheers!

Ravi

Synchronous rectifier load test: Temperature taken after 10 minutes of load. Test board same as my previous post with 1oz copper pcb. Voltages measured at input to test board and output of test board. Single rectifier tested no averaging. Ambient temp 22C. Temperatures rounded up to nearest whole degree C. open air no case.

current draw | input voltage | output voltage |temperature of | temp of controller

in A | to rectifier VAC | after 3300uF cap | hottest psmn040 |

3A 16.2 18.6VDC 107C 69C

2A 16.6 20.2VDC 61C 45C

1A 17 21.8VDC 34C 31C

So it looks like 2A at fine. 3A is pushing it a bit hard at these voltages.

Edited January 2, 2021 by jamesmking

sbelyo · September 21, 2020

I thought about the parts I have for building 30V GRLV boards for my dynahi, I noticed that the tantalum caps are all rated at 25. Should I increase them to 50V when building for 30V?

gepardcv · September 21, 2020

I used TAP106K035CCS and TAP476K035CCS, rated for 35V. They seem to work fine...

ang728 · September 21, 2020

4 hours ago, sbelyo said:

I thought about the parts I have for building 30V GRLV boards for my dynahi, I noticed that the tantalum caps are all rated at 25. Should I increase them to 50V when building for 30V?

47uf tants are fine with 25V, but 10uf ones should go up to 35v or above

Edited September 21, 2020 by ang728

*johnwmclean* · November 7, 2020

Just as an FYI mouser are now stocking LT1021.

*JoaMat* · March 10, 2021

Anyone feels like taking care of three Golden Reference boards version .44?

Then ping me.

GGW · May 3, 2021

Hi Gents,

1.) Please could someone point me in the direction of the version .47 of the GRLV board? I can't see it on the share drive 😕

Separately, I have 2 additional questions if anyone could please help me:

2.) What is the latest / greatest / preferred GRLV version for each of the Dynalo and CFA2 x 4 (dual / balanced craziness; or 2 x CFA3 boards) ?

3.) I noticed there is another little PCB called "GR78xx" - would I need to get a few these printed as well? Or is it optional? If optional, what's the benefit?

Thanks in advance for the guidance!!

*jamesmking* · May 3, 2021

23 minutes ago, GGW said:

Hi Gents,

1.) Please could someone point me in the direction of the version .47 of the GRLV board? I can't see it on the share drive 😕

Separately, I have 2 additional questions if anyone could please help me:

2.) What is the latest / greatest / preferred GRLV version for each of the Dynalo and CFA2 x 4 (dual / balanced craziness; or 2 x CFA3 boards) ?

3.) I noticed there is another little PCB called "GR78xx" - would I need to get a few these printed as well? Or is it optional? If optional, what's the benefit?

Thanks in advance for the guidance!!

GR78xx and gr79xx are surface mount versions of the golden reference LV without the input or output smoothing capacitors.

In general the golden reference LV come in dual (both positive and negative supplies on one pcb) or separate plus and minus pcbs. The gerbers can be found at:

https://drive.google.com/drive/folders/0B_iJFfZStuVhSE5nOHBVdTByR1k

the latest dual golden reference that I know about is goldenreference6D.zip this is marked on the pcb as version 0.45: the dual output board has provision for 25mm diameter input smoothing cap and optional output on led.

https://drive.google.com/file/d/0B6JqIzEX9jZ0LTQ4ZG9HTDE2U0k/view?usp=sharing

the individual rail pcbs are goldenreference6minus.zip and goldenreference6plus.zip:

https://drive.google.com/file/d/0B6JqIzEX9jZ0ejFrM2lQZnFMa0U/view?usp=sharing

https://drive.google.com/file/d/0B6JqIzEX9jZ0R1NpaDNuSzl4NHM/view?usp=sharing

there is a goldenreference7plus.zip and minus but the pcb markings for them say 0.43 and do not have an option for a led showing the output is on, however the board allows for a larger diameter input smoothing cap at ~35mm diameter.

https://drive.google.com/file/d/0B6JqIzEX9jZ0UFRaQzJSd1UwOTQ/view?usp=sharing

and

https://drive.google.com/file/d/0B6JqIzEX9jZ0YksyazZ0QXZ5djg/view?usp=sharing

Edited May 3, 2021 by jamesmking

GGW · May 5, 2021

Thanks, @jamesmking - very helpful.

I've read this entire thread and there are 3 updates to the version .45 board (see file names including the version on the silkscreen, in the snip below):

For context, the descriptions Kevin uploaded with each:

version 0.46 "rflip"

because soren is running the grlv supply at 4.5 amperes, here is a new version with the feedback resistor locations flipped so that the sense is not one inch away from the output connector.

sense is now tied directly to the inner power supply connector. So the 20mv change in voltage due to current should be completely canceled out.

for higher currents, best if the board is made with 3 oz copper.

version 0.47 "rflip to220"

here is the version with the to220 sic diodes, someone really needs to check this

version 0.48 "largecap"

same size board, up to 35mm caps, had to move the pass transistors, needs checking silicon carbide rectifiers 100mm x 109mm

I think @Pars mentioned the v0.48 is basically the v.45(?) with fatter, shorter (?) caps for when height is a constraint - is that correct?

*******

My questions -

(1.) are these all improvements (is version 0.48 the best in all use cases?) or are each of versions 0.46-0.48 just tweaks for specific use cases ?

(2.) Which board is best suited to (a.) power the SS Dynalo (mk2 "multiamp"); and (b.) power balanced CFA boards (i.e. 2x CFA2 or 1x CFA3?

Many thanks as always for the guidance! (For context - I'm trying to pull the trigger once on a PCB order, so trying to figure out the right versions of all the boards I need to avoid multiple shipping charges... i.e. GRLV, Dynalo, CFA2 or CFA3, etc.)

starcat · May 8, 2021

You can use the goldenreference6D.zip and skip yourself the further hassle. It has been checked and built numerous times and is more than good enough.

Edited May 8, 2021 by starcat

*Pars* · May 8, 2021

I'd use something with 2 sets of outputs. You can thank me later (cough cough gilmore_protect board cough cough).

starcat · May 8, 2021

Hey Pars, the goldenreference6D.zip has two sets of outpus.

*Pars* · May 8, 2021

Great. Didn't look at it. Go for it.

starcat · June 16, 2021

Found a very nice 4700uF 50V cap for the GRLV, dia 25mm (instead of 20mm) and 30mm high (instead of 40). Shorter and fits very nicely.

GGW · July 6, 2021

@starcat @Pars - thanks a ton.

Immensely helpful as always!

ShortBtwnHdset · July 23, 2021

Hello!

First post on these forums; joined when I became interested in the Dynalo while web-surfing. I really need help, as I think I've bitten off more than I can chew. Bought a pair of SuSy Dynalo boards and this PS board off of Ebay with included, fairly well matched transistor sets (https://www.ebay.com/itm/334044891985). Finally received them mid week. Version number for the GRLV board is .44, for the SuSy boards is 1.1. I've tried to no avail to follow the page1 links from Kevin at the .edu site to try and get schematics and BOM for boards, but my browser keeps timing out (from America). Getting the board manuf files doesn't seem to be a problem, though, as the links work. I've read through many but not all pages of this and the "and now for something completely different part 3" threads, and am currently overwhelmed by it all!

It sounds like I need to start with the PS board and what general parameters I want my build to have. So I guess I need a target voltage for powering the SuSy boards, a schematic for this GRLV board, and a BOM for this board to start. Also, which PS thread and Dynalo thread should I follow for the build?

Progress on this will be slow, as I have several LT home projects happening as well. I have basic electronics knowledge, am handy with a VOM and a soldering iron, and I'm handy with hand tools, but nothing beyond that. I've never built one from the ground up. Have I screwed up buying this?

Thanks in advance for all replies.

Edited July 24, 2021 by ShortBtwnHdset

*Pars* · July 24, 2021

Kevin retired from Northwestern Univ. (the .edu links) a few years ago, so those links are no longer valid. The Stax thread will provide google drive links to the board files and other documents.

For a Dynalo, you will want +/-20V for the GRLV. There are BOMs for the GRLV posted in the thread. Sorry, but we don't provide build guides, etc. here. Going thru both the Dynalo and the Golden Reference LV threads should provide you with all you need to know. Build the GRLV first, and test it unloaded to make sure it is performing properly. Pretty easy build. And I would stay out of the and now for something completely different part 3" thread for now. The Dynalo is a very good amp. Not sure what phones you are intending this for, but the CFP 2/3 is a very good amp.

gepardcv · July 24, 2021

@ShortBtwnHdset: Don't let Pars scare you away. No build guides doesn't mean you won't get answers.

The Dynalo is easy. That kit you bought looks pretty good, assuming the MPSW parts really are genuine and matched as advertised. Look at BOMs, but above all follow the silkscreen on the boards. Stuff the boards. Check the GRLV board you have for the type of transformer secondary windings you'll need, whether center-tapped or not (there are a couple of different GRLV versions floating around). I used an Antek 50VA 22V for a Dynalo, it worked great, but might not be right for your GRLV board. This thread will have more info.

Do you know how to safely wire up mains? That'll be the next challenge. It's also not difficult, but needs to be done carefully and correctly.

While the wiring is pretty self-explanatory, you'll also need to ground the amp correctly to avoid noise. Again, there's info in various threads (including the KGSSHV thread), and feel free to ask when you get that far.

ShortBtwnHdset · July 27, 2021

Thank you to both Pars and Gepardcv for your posts. I do appreciate it.

It seems when this thread was active, and when Kevin was involved, a lot of ya'll worked out the kinks and got a lot of great PS's made. But since the fervor has died down and the web links eventually were outdated, this design doesn't have as active a community supporting it. I realize I'm both late to the party and have probably over-reached. I've tried to read thru all 27 pages of this thread, but there seems to be no working link for a schematic for the GRLV in any version, nor a BOM or even parts list to go by since the .edu links went down. Pars has broken links on pg 25, and the google docs pages don't seem to show either, just the board layout/manuf files for this and many other projects. I can piece some of it together thru the thread, but for instance, what wattage resistors do I get, 1/2 watt, 1 watt, etc. Do the electrolytics need to be polarized? I don't see any mention of what bridge rectifiers your using, and is it 1, 2 or 3 (I think its two, depending on transformer, but that's yet another series of questions)? Or is there a supplier for the schottky mini-boards? There is just so much information to read thru, and most of what I read I don't understand. Pars seems to have built a GRLV with 20V rails to power a SSDynalo, so I can glean some from his and other posts, but that leaves me in the dark on an awful lot.

I don't want ya'll to hold my hand, but working without a schematic and a parts list at minimum seems ludicrous. Can ya'll help me out?

PS: forgot to mention I think my board layout is the goldenreference6.zip version

*mwl168* · July 27, 2021

All the polarized caps on the PCB are clearly marked with the polarity and voltage rating. Measure the dimensions and lead spacing of the board to decide which caps to order. Most of us used 1/2W resistors for our builds although 1/4W ones probably suffice in most if not all positions.
Take a close look at the photos posted in the thread should also give you lots of information.
With many parts becoming obsolete, locating an old BOM may not help you very much.

*JoaMat* · July 27, 2021

4 hours ago, ShortBtwnHdset said:

.... working without a schematic ....

Me too like schematics.

I believe this goldenreference.pdf reflects goldenreference6.zip version.

*jamesmking* · July 27, 2021

On 7/27/2021 at 4:37 AM, ShortBtwnHdset said:

I don't want ya'll to hold my hand, but working without a schematic and a parts list at minimum seems ludicrous. Can ya'll help me out?

PS: forgot to mention I think my board layout is the goldenreference6.zip version

Golden Reference LV Build Guide

Schematic for the golden reference LV:

parts in green are new additions compared to the published schematic pdf in joamats post above. Parts in purple set the output voltage, parts in brown are the optional fine output adjust and parts in dark blue are the optional power led.

Component Layout

Optional parts and Options:

1. if you don't want to have a power led fed from the LV board omit the 2K resistors R13, R14 and the led D3

2. if you don't want very fine adjustment of the output voltage omit the 1M resistors R17, R18, R23, R24 and the trimmers RV2 and RV1. If you want more adjustment range reduce the value of the resistors. With 1M ohm resistors the fine adjust can only change the output voltage by a few mV. Replacing with 810K resistors provides a little more adjustment range ~ 20mV but at the expense of decreasing the temperature stability. A cheaper alternative for good output accuracy is to use 1/4W 0.1% low ppm e.g. 15ppm resistors for the voltage set resistors and omit the fine adjust completely - which is cheaper and improves the temperature stability.

3. if you have the dual output board (which has both positive and negative output rails) either you populate the middle diode bridge only and use a transformer which is centre tapped OR you populate the two outer diode bridges and use a transformer with two separate output windings. If use use synchronous rectifiers instead of diode bridges use must use the second option and use separate windings for positive and negative rails. Do not populate all three bridges. If you use a centre tapped transformer you must connect the centre tap to the middle screw terminal (which is connected to the GRLV ground plane) of the 5 terminal AC input block . Do not use a synchronous rectifier to the centre bridge it will not work correctly and can result in the driver mosfets of the synchronous rectifier burning.

Note the GRLV cant output less than the voltage of the voltage reference (LT1021), ideally for proper regulation the output needs to be more than about 2V higher than the LT voltage reference. So for about 12V or less output it is recommended you change the 10V reference for a 7V and the zener diodes for a 7V. For 12V output 10V reference or 7V reference can be used but the 7V reference version may have less noise. Maximum output is constrained by the voltage rating of the caps and is about 30V without modifications.

Setting the Output Voltage

For the positive output R8 and R7 control the output voltage along with the voltage reference,

the output voltage is ((R7+R8)/R7)*voltage reference output D5. Assuming you keep R7 at the stock value of 1.5K:

output voltage change R8 to
3k = 30V
1.5K = 20V
750 = 15V
300 = 12V

In general to calculate R8: ((Voltage required * R7)/voltage reference D5 output) - R7 = R8

For the negative output R10 and R9 control the output voltage along with the voltage reference,

the output voltage is ((R10+R9)/R9)*voltage reference output D7. Assuming you keep R10 at the stock value of 1.5K:

output voltage change R9 to
3k = 30V
1.5K = 20V
750 = 15V
300 = 12V

In general to calculate R9: ((Voltage required * R10)/voltage reference D7 output) - R10 = R9

Photos of finished boards for reference:

This version uses a single diode bridge so this is setup for a centre tapped transformer, also has the trimmers and resistors for the power led populated but no power led installed. The build uses 4700uF reservoir caps and silmic 220uf output caps and 1/4w resistors from vishay and dale. This is what you get using the BOM link in this post (see bellow) and is very close to the original BOM published near the beginning of this thread.

This version is setup for dual separate transformer windings, and has no power led or trimmers implemented. It also uses synchronous rectifiers instead of diode bridges, nippon chemicon 10000uF reservoir caps, Panasonic FR series 220uF caps and 1/2W 50ppm 1% koa resistors. The resistors that set the output voltage are 1/4W TE 0.1% 15ppm for increased temperature stability and output accuracy. This is my current default build.

BOM (based on 10V voltage reference and all options being populated)

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=edda1bdbf7

Component list with cap size information

Br1,Br2,Br3 = 2 x 4A 100V RS402L use 2 for dual winding transformer use 1 for centre tapped transformer

C,C = 2 x film 4.7uF 50V 5mm lead spacing 0.5mm lead diameter

C,C,C11,C12,C14,C15 = 6 x film 0.01uF 100V 5mm lead spacing max size ~ 7.6mmx3mm 0.5mm lead diameter

C1,C2 = 2 x 50V 4700uF 10mm lead spacing max diameter 25mm, 22mm more comfortable fit main reservoir cap I also use Nippon Chemicon 63V 10000uF which just fit.

C3,C16 = 2 x Tantalum 35V 10uF ESR=2 Ohms 5mm lead spacing 0.5mm lead diameter

C4,C5 = 2 x Multilayer Ceramic 50V 47pF 5mm lead spacing 0.5mm lead diameter

C6,C10 = 2 x 220uF 35V silmic or Panasonic FR series 5mm lead spacing 12.5mm max diameter

C7,C8,C9,C13 = 4 x tantalium 35V 47uF ESR=0.8ohms 5mm lead spacing 0.5mm lead diameter

D,D,D,D = 4 x 1N914

D1,D2,D3,D8,D9 = 5 x 1.7V red led 4 are required one is for optional power led leally all 4 main leds should be from the same batch and have similar characteristics.

D10,D11 = 2 x IN4007G 1A 1000V

D4,D6 = 2 x IN4739A 9.1V 1W use 7V zener for <=12V output

D6,D7 = 2 x lt1021-10 10V voltage reference use 7V for <=12V output

Q4 = 1 x MJW21194G

Q5 = 1 x MJF15031G

Q7 = 1 x MJW21193G

Q9 = 1 x MJF15030G

Q1,Q3,Q6,Q13 = 4 x KSP92TA

Q2,Q10,Q11,Q14 = 4 x KSP42TA

Q8,Q12 = 2 x DN2540N3-G

R1,R4 = 2 x 150 1/2W

R13,R14 = 2 x 2K

R15,R16 = 2 x 10K

R17,R18,R23,R24 = 4 x 1M, 810K = +-20mv adj range optional for fine adjustment

R2,R5,R11,R12 = 4 x 1K

R20,R21 = 2 x 500

R3,R6,R19,R22 = 4 x 10

R7,R10 = 2 x 1.5K

R8,R9 = 2 x 750 for 15V output change as necessary for your output

RV1,RV2 = 2 x 100K optional for fine adjustment

U1,U2 = 2 x OPA134PA opamp

Building

Once you have decided the build options and output voltage, construction is straightforward given there are no high voltages. Depending upon the current draw the large power transistors on the side of the board may require heatsinking. The metal tab is live so they will need to be insulated from the heatsink/chassis.

Socketing the reference and opamps is optional but it does make replacement and reuse easier.

Make sure the caps are installed with the correct polarity. The line on the tantalums denotes the positive Terminal whereas the line on electrolytic caps denotes the negative terminal.... the film caps can be installed either way around as can the small ceramic caps.

For the leds the longer leg is the + leg and this goes to the + mark on the pcb

be careful to install the opamps and voltage reference chips the correct way around they will get very hot very quickly if installed the wrong way.

make sure you don't place as ksp42 where a ksp92 should go of visa versa. Its easy to do since they look identical and its not easy to see all the markings once populating the board is finished.

Testing (optional)

If you have a means to control the input voltage to the board e.g. a variac, then with no load connected to the grlv the outer leds (closest to the LT voltage reference) should just start to glow at about 2.4 to 2.5VAC rms input voltage to the board and the output of the GRLV should be around 1V DC. If you cant get the outer leds to light with about 3VAC rms input, stop and disconnect, something is definitely wrong. By 3VAC rms the outer leds should be bright.

Increasing the variac output further should see proportional rises in the GRLV DC output voltage until the output reaches the expected output. At this point the inner leds closest to the zener diode may not have lit and although basic regulation has been achieved, the input voltage is too low for full low noise regulation. Increase the input voltage a little more and the inner leds should light. This should happen with after about an additional 1 volt AC rms is added to the input. The output voltage should not increase.

As a very rough rule of thumb, without load, the grlv needs about 2V less input AC rms than its DC output. So for example for 12v output expect regulation to just happen at about 10VAC rms input but the inner led not to light until about 11VAC rms. Note this figures depend on tolerances, the diode bridge voltage drop, led characteristics etc and are a rough guide only. Adding a load to the GRLV will mean it needs a higher input voltage in order to regulate since some of the sources of voltage drops are dependant on current draw e.g. the diode bridges. So if you adjust the variac to just get the inner led lit with no load don't be surprised if it goes out when you draw a few hundred milliamps.

Another way to test is to connect the AC in of one rail to a current limited DC power supply. Set the current limit to say 0.010A (10mA) and slowly increase the voltage. Bellow about 3.3VDC input to the GRLV there should be low current draw <10mA. At about 3.4VDC the outer led will start to light and current draw should still be <10mA. Around 8.5VDC input current draw should reach about 10mA. The inner led close to the main cap should begin to light at about 2.6VDC input above the expected output e.g. 14.6VDC input for 12V output. At this point current draw should be about 20mA and you may need to increase your DC power supply current limit. Increasing the DC power supply output past this point should not result in increasing current draw or increasing GRLV output. Note when you increase the DC power supply voltage you will get an initial current draw spike as the input cap charges to the new voltage level but the current draw should quickly subside to the figures shown.

If the GRLv regulates and behaves as expected with no load and has no warm components or varying output then you could continue to load testing. The reality is that if your RLV works with no load its almost certainly ok and will be fine without load testing. But if you want to be extra careful the easiest way to do this is with an electronic DC load. I setup my load so that it will abort the test if the output voltage of the GRLV exceeds 0.2V above or bellow the no load output. A properly working GRLV with enough input voltage will vary very very little with current draw - much less than a traditional 78xx/79xx voltage regulator. I then load at 50mA and check for hot components, and then in 100mA steps up to 1A. Above about 400mA the large main transistors will get hot if they are not heatsinked... this is normal as the current draw increases there is more power dissipation in the transistor. Note transformers and diode bridges etc do drop more voltage as the current draw increases so if the inner led goes out at higher current draws check the input voltage to the GRLV has not decreased too much for the GRLV to regulate. Don't load test about above 300mA for long periods without heatsinking the main transistors.

Additional Checks (useful if troubleshooting)

The voltage reference output voltage should be present between pins 4 and 6 of the LT reference and be stable and very close to the spec sheet voltage. Use fine tip probes and be careful not to short any pins together when probing:

The opamp compares the voltage reference with the output voltage from the voltage divider (the resistors which set the output voltage) and creates a correction signal. Pin 2 of the opamp is connected to the voltage reference and pin 3 is connected to the voltage divider. When working correctly, the voltages with respect to ground to pin 2 and from ground to pin 3 should be identical and be the same as the output of the voltage reference measured above.

In circuit testing and troubleshooting

So its not working correctly or you want to do some more tests before powering on for the first time?. Here are some tests you can do on a fully built GRLV that has no power connected. With a multimeter set to diode check mode and the caps on the grlv fully discharged. you can do some sanity checks. The exact measurements will vary from multimeter to multimeter and device to device but this should give some ball park figures. My figures are based on a Brymen bm869s.

Led polarity

outer leds closest to the edge of the pcb and the voltage reference:

red lead of multimeter to + lead of led, black on - lead of led ~ 0.8V slowly rising as a cap charges led does not light. leads reversed: 1.63V slowly rising led does not light

inner leds closest to the main input filter caps:

red lead of multimeter to + lead of led, black on - lead of led ~ 1.7V stable voltage led should light. leads reversed: over range / OL / open circuit, led does not light.

Zener check both zeners close to the inner leds:

red probe on band side black on non band side: OL / open circuit, probes reversed 0.66V

Transistor Death/Incorrect Placement Checks

large MJW21194 on +rail measuring looking at the front of the transistor where the markings are:

red probe on left pin black on middle pin: 0.46V steady, probes reversed OL / open circuit

red probe on left pin black on right pin: 0.48V steady, probes reversed OL / open circuit

red probe on middle pin black on right pin: 0.5V rising rapidly, probes reversed 0.48V rising much more slowly

large MJW21193 on -rail measuring looking at the front of the transistor where the markings are:

red probe on left pin black on middle pin: OL / open circuit , probes reversed 0.48V steady

red probe on left pin black on right pin: OL / open circuit, probes reversed 0.49V steady

red probe on middle pin black on right pin: 0.48 rising slowly, probes reversed 0.5V rising much more rapidly

MJW15030 on +rail next to inner led:

red probe on left pin black on middle pin: 0.57V steady, probes reversed OL / open circuit

red probe on left pin black on right pin: 0.57V steady, probes reversed OL / open circuit

red probe on middle pin black on right pin: OL / open circuit , probes reversed 0.46 steady

MJW15031 on -rail next to inner led:

red probe on left pin black on middle pin: OL / open circuit, probes reversed 0.57V steady

red probe on left pin black on right pin: OL / open circuit probes reversed 0.57V steady

red probe on middle pin black on right pin: 0.48 steady probes reversed OL / open circuit

KSP42 on +rail on edge of board: looking at flat front where the marking are

red probe on left pin black on middle pin: 1.8V rising, probes reversed 0.6V steady

red probe on left pin black on right pin: 1.2V rising, probes reversed OL / open circuit

red probe on middle pin black on right pin: 0.6V steady probes reversed OL / open circuit

KSP92 on -rail on edge of board: looking at flat front where the marking are

red probe on left pin black on middle pin: 0.61V steady, probes reversed 1.7V rising

red probe on left pin black on right pin: OL / open circuit. probes reversed 0.9V rising

red probe on middle pin black on right pin: OL / open circuit, probes reversed 0.6V steady

DN2540 on +rail between voltage reference and 220uf output cap

red probe on left pin black on middle pin: 0.31V steady, probes reversed 0.32V steady

red probe on left pin black on right pin: 0.004V steady. probes reversed 0.004V steady

red probe on middle pin black on right pin: 0.32V steady, probes reversed 0.32V steady

DN2540 on -rail between voltage reference and 220uf output cap

red probe on left pin black on middle pin: 0.32V steady, probes reversed 0.32V steady

red probe on left pin black on right pin: 0.004V steady. probes reversed 0.004V steady

red probe on middle pin black on right pin: 0.32V steady, probes reversed 0.32V steady

KSP92 on +rail near centre of board close to middle diode bridge: looking at flat front where the marking are

red probe on left pin black on middle pin: 0.6V steady probes reversed OL / open circuit

red probe on left pin black on right pin: 1.0V rising slowly, probes reversed OL / Open circuit

red probe on middle pin black on right pin: rises to about 0.67V, probes reversed 0.56 steady

KSP42 on -rail near centre of board close to middle diode bridge: looking at flat front where the marking are

red probe on left pin black on middle pin: OL / Open circuit, probes reversed 1.61V steady

red probe on left pin black on right pin: OL / open circuit. probes reversed 0.95V rising

red probe on middle pin black on right pin: 0.59V steady, probes reversed 0.67V steady

the pair of KSP92 on +rail ksp92 closest to voltage ref: looking at flat front where the marking are

red probe on left pin black on middle pin: 0.62V steady probes reversed OL / open circuit

red probe on left pin black on right pin: OL / open circuit, probes reversed 0.61 steady

red probe on middle pin black on right pin: OL open circuit, probes reversed 0.61 steady

the pair of KSP92 on +rail ksp92 closest to the inner led: looking at flat front where the marking are

red probe on left pin black on middle pin: 0.59V steady probes reversed OL / open circuit

red probe on left pin black on right pin: 0.59V steady, probes reversed OL / open circuit

red probe on middle pin black on right pin: 0V / short, probes 0V / short

the pair of KSP42 on -rail ksp42 closest to voltage ref: looking at flat front where the marking are

red probe on left pin black on middle pin: OL / open circuit, probes reversed 0.59V steady

red probe on left pin black on right pin: OL / open circuit , probes reversed 0.59V steady

red probe on middle pin black on right pin: 0V / short, probes 0V / short

the pair of KSP92 on +rail ksp92 closest to the inner led: looking at flat front where the marking are

red probe on left pin black on middle pin: OL / open circuit, probes reversed 0.61 steady

red probe on left pin black on right pin: 0.62V steady probes reversed OL / open circuit

red probe on middle pin black on right pin: 0.61V steady, probes reversed OL open circuit

Good luck with your build and thank you to everyone who contributed to the design of the GRLV and this thread.

Edited July 29, 2021 by jamesmking

ShortBtwnHdset · July 27, 2021

First off, let me say THANK YOU!!!

JamesMKing, wow, you went really over the top on this and made an amazing guide! I hope many will benefit from it. I know I definitely will! I'm going to read thru carefully and make an order for the first parts tonight. Thank you again!

Also, thank you to mwl168 and JoaMat. The experience all of you guys have invested in this thread is a really nice resource to have.

starcat · July 27, 2021

Excellent writeup as always, thx James.

On a side note, for the inner Phoenix 3P connector, I am using the rised version of it, just to make wiring easier. Here how it looks like.

*Beefy* · July 27, 2021

6 hours ago, jamesmking said:

Golden Reference LV Build Guide

Fucking epic. Not all heroes wear capes!

37 minutes ago, starcat said:

On a side note, for the inner Phoenix 3P connector, I am using the rised version of it, just to make wiring easier. Here how it looks like.

Wow, nice find. Heaps of places I could have historically used those, if only I realised I needed them!

goldenreference low voltage power supply

Recommended Posts

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

jamesmking

Kerry

Kerry

Posted Images

Create an account or sign in to comment

Create an account

Sign in

Important Information