Author Topic: Volt reference DIYer LTZ 10V PWM  (Read 15580 times)

0 Members and 1 Guest are viewing this topic.

Offline Andreas

  • Super Contributor
  • ***
  • Posts: 3222
  • Country: de
Re: Volt reference DIYer LTZ 10V PWM
« Reply #25 on: July 09, 2017, 04:06:51 am »
Assuming, of course, that noise amplifier was connected when picture was taken.

That question is answered in the video.
(don´t know wether the "Lab" supply for the reference is also a switchmode supply).

with best regards

Andreas


 

Offline Kleinstein

  • Super Contributor
  • ***
  • Posts: 14076
  • Country: de
Re: Volt reference DIYer LTZ 10V PWM
« Reply #26 on: July 09, 2017, 08:17:45 am »
The LED circuit shown is odd: The LED would turn off if the signal gets close to saturation. Normally both LEDs would be on.
So both LEDs on is OK, but hard to tell (especially from a photo)  if there is some clipping.

With only 25 mV at the output I would not expect clipping.
 

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #27 on: July 11, 2017, 06:58:33 am »
Today I received LTZ1000 Ref. pcb and 2DW232 (date code 15-4),
noise meter is on the way.
« Last Edit: July 11, 2017, 07:12:59 am by 0.01C »
0.01℃
 

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #28 on: July 11, 2017, 07:18:41 am »
Do you want the 7-10 and ltz ref. PCB ?I can send you one set.

Sure, I'm planning four 10V-10K reference modules, but I have parts for 5 sets (backup) so I could build one on your PCBs first before designing my own reference mini-module. I'll PM you.

We have done several times group buy vishay resistor ,VHP101T 100R 9.998K ,VHP202 9.998K  ,VHD200T 6K3:13K8........

I think we should introduce this bbs.38hot.net tradition here at the eevblog forum :) So far I managed to buy some 2DW233 thanks to technix's group buy initiative.
BTW This box of Vishays is a small fortune :)

what is the date code of your 2DW232?

what color of the ltz cover you like?
0.01℃
 

Offline lukier

  • Supporter
  • ****
  • Posts: 634
  • Country: pl
    • Homepage
Re: Volt reference DIYer LTZ 10V PWM
« Reply #29 on: July 11, 2017, 08:26:22 am »
what is the date code of your 2DW232?

Hmm, no date code on the package. Just factory logo and 2DW233. Yellow painted dot on the side (see picture).

what color of the ltz cover you like?
Doesn't matter :) If you are short on covers don't worry, I have a 3D printer so I can print it.
 

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #30 on: July 11, 2017, 08:36:23 am »
what is the date code of your 2DW232?

Hmm, no date code on the package. Just factory logo and 2DW233. Yellow painted dot on the side (see picture).

what color of the ltz cover you like?
Doesn't matter :) If you are short on covers don't worry, I have a 3D printer so I can print it.

no date code ? :-X
0.01℃
 

Offline tszaboo

  • Super Contributor
  • ***
  • Posts: 7307
  • Country: nl
  • Current job: ATEX product design
Re: Volt reference DIYer LTZ 10V PWM
« Reply #31 on: July 11, 2017, 08:59:22 am »
I was sending a similar PWM + LTZ1000 reference into production once. Though the application was different, I needed stable 5V from the 7.2 instead of 10, but the principle is very similar.
I'm missing something from all these schematic, which was very important in my experience. R30 and R31 (from the PWM10V1 schematic) has to be low tempco, big physically, and special care has to be done for the routing. C44 and C45 also. Foil capacitors to start with, with as small leakage as possible. Otherwise there will be problems, like leakage shifting the output, and the like. I even put a leakage guard trace (driven by a whatever opamp) below C44 and C45, protecting that entire node. All leakage gets multiplied by 100KOhm so thats why.

Otherwise the circuit is... a copycat. Not doing judgement, but there are better opamps available than back then. Also, the JFET switches  :-\
 

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #32 on: July 11, 2017, 11:31:43 am »
4 noise meter just arrival >:D

« Last Edit: July 22, 2017, 01:05:00 am by 0.01C »
0.01℃
 

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #33 on: July 15, 2017, 05:40:05 am »
All 10V LTZ PWM reference and noise meter has been sent, I hope they enjoy, I also sent some different date code of 2dw to a member for test and comparison.

« Last Edit: July 15, 2017, 07:36:47 am by 0.01C »
0.01℃
 
The following users thanked this post: Muxr

Offline 0.01CTopic starter

  • Regular Contributor
  • *
  • Posts: 91
  • Country: hk
Re: Volt reference DIYer LTZ 10V PWM
« Reply #34 on: July 22, 2017, 01:10:33 am »
@Charlie Beuning USA

My friend contact me today said you have bought a noise meter from his taobao shop ,
but there is no stock now ,please pm me,Thanks
« Last Edit: July 22, 2017, 01:30:07 am by 0.01C »
0.01℃
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf