On 13.2.2018 at 9:44 PM, sorenb said:

Yes, check your rectified input voltage ...probably too low ...or you might be pulling too much current >3A or so

Rectified I get ~24 . The load is a Dynalo Mk2 not sure how much it pulls and the amp is at work. Need to take it home for deeper analysis.

Will take it home and follow up.

 

Edit: Fixed it was the Voltage Reference. Followed the voltage through the whole board to find that it's not doing it what it should.

Edited February 15, 20188 yr by masamoto

Hi, new to Head-Case.org.   I wish to build Kevin's GRLV;  going over BOM, MJW21194G/93G and MJF15030G/31G is not available through the reliable Mouser nor Digikey distributors.   Am I overlooking a source that most are using for the BJT's?   I think not, so can you recommend alternative (s) for both complement pairs.   The GRLV will be used for Kevin Gilmore's KAS5 Klone.   Thanks.

 

Mouser had the MJF15xxx parts in stock, but is out of the MJW2119x parts. Arrow has all of them in stock, and are reputable.

I'm not sure if you could use the MJW21195/21196 instead (which Mouser does have in stock). I seem to recall Kevin saying those are fine. Looking at the datasheets for both, I can't spot any difference, but of course there must be something.

https://www.head-case.org/forums/topic/12269-goldenreference-low-voltage-power-supply/?do=findComment&comment=732948

Par,  thanks for the lead.  

 

Guys ,do i need heatsinks for the grlv, for 20v, to use with the dynalo?If yes small ones will do?

Thanks

Edited March 24, 20188 yr by ti5002000
edit

It depends on the max current draw, doesn't it? For 20V with a SS Dynalo, for example, you need some heatsinking, but not a huge amount. For those builds, I just attach the devices to the aluminum chassis (through a pad, naturally) and it works well. For 30V with a SS Dynahi, I attached them to large external heatsinks.

Edited March 24, 20188 yr by gepardcv

Is it the original, single ended  Dynalo or the SS Dynalo?  And how much voltage drop between the pre-reg and regulated output?

 

You probably should have something on there. Most people seem to mount them to the case bottom. On mine, which is uncased so far, I use a clip on heatsink like this:

36 minutes ago, mwl168 said:

Is it the original, single ended  Dynalo or the SS Dynalo?  And how much voltage drop between the pre-reg and regulated output?

 

It will be for the ss dynalo and i will be using 22v secondaries transformer.

35 minutes ago, Pars said:

You probably should have something on there. Most people seem to mount them to the case bottom. On mine, which is uncased so far, I use a clip on heatsink like this:

yes, i have some small ones more a less the size of those.It´s just, if i can use those, i wouldn´t need to do more holes...

Mini and micro versions of the gr78xx supplies...

That's really a disguised silver dollar there, isn't it Kerry

Very cool! Now, tell me what these will do?

Got the micro up and running.  This is set for 12v.

Depending on the op amp this should support from 5v to about 20v.

The larger should support from 12v to 50v.

Noise looks good but I really need a screened room.

 

great  job!  kerry

Here's the HV version set to 450v.

Have to test this one still.

gorgeous

Sent from my Pixel 2 XL using Tapatalk

Wow!  

Seriously impressive Kerry (as usual )

Kerry, what is feeding these during the testing (bench supply?) and what is the load? Would you be able to do some measurements with some decent ripple in the input (say 500mV) and a decent load (1A?)

1A at 450V – yeh, that’s a pretty decent load

I should be able to test the low voltage version with some decent ripple at 1A a bit later in the week.

I was able to get the 450v supply up and running.  I did have one error on the board.

The current source feeding the 10v reference gets up to 150 degree F, but I can add more copper around it.  I think it will be just fine.

I was running this with a 110mA load.

Edited April 10, 20188 yr by Kerry

That’s just so incredible. Awesome work Kerry. 

Here's the accompanying board for the GR HV & LV supplies.

It's got a built-in controller to turn the HV on after a delay (if needed) along with a power LED indicator (flashing to solid).

I've also added a tap for both Normal and Pro bias.

Nice. Like the 08N100D up there.

IC1 is?

It's an optional 5v regulator (LM7805CDT) to power the delay timer.

You can also use an external supply for the that.

I've set this up so you can use either the built in current regulator on the grhv78xxx or the 08N100D as an external regulator.