Recent Posts

Pages: [1] 2 3 4 5 6 ... 10 Next
1
Probably you have to write 3 CAD programs from scratch. The first 2 will be rubbish and the third one will be useful because by then you understand what workflow works.
2
Projects, Designs, and Technical Stuff / Re: Linear lab power supply
« Last post by JuanGg on Today at 09:10:14 am »
Alright, thanks for spotting that. I'll make those changes and hopefully order tomorrow or the following day, as most prototype services in China close for the Chinese new year and I want to get this thing made sooner than later. I'll do some more testing on the current sense amplifier if I'm able to.
    Juan
3
Repair / Re: Replace LCD on HP/Agilent 664XA PSUs
« Last post by Gandalf_Sr on Today at 09:09:36 am »
I just got a pm from eb4eqa on how he implemented his replacement OLED for the 6632B PSU but it seems way more straightforward than what I'm attempting as the characters coming from the PSU are just a stream of ASCII where one byte represents one character on the display (from what he sent me).

We're trying to decode the 14 segment display bits that have been sliced, diced, and blended together!  It may well be that the bits in the 3 nybbles correspond to specific segments lit up on the old Omron display (e.g. there's only 1 bit difference between 8 and 9) so the decimal point and captions must be separately encoded.  Anyone got any idea how they are encoded?  It looks like they are in the stuff to the right of 18 x 12-character bytes.

I'll keep looking at it as it may be possible to decode what each char looks like from the segments it lights up and that would allow me to figure out how to decode 12 segments to ASCII but a lookup table is the logical way to implement the electronics, either way there are 4096 possible permutations of 12 bits so you feed the 12 bits into an array and it spits out the ASCII character to display.
4


Yep, Flukes are really great in maintaining their specs. I have had over 9 flukes 25's and 27's all ex military with calibrations dates that were many years out of date and yet when I hooked them up to a standard AD584M and other good reference sources, all agreed with each other. I have since sold most of these now and have replaced them with more modern bench meters, the 8840A and 8842A and again both these were years away from a known calibration and yet they also agree with each other against my normal calibrations standards, once they have been given the requisite warm up period  :-+

This 8810A was frigid cold when I unpacked it. It only got up to about -12 C today. And it sat in a (probably unheated) UPS warehouse all weekend. So I knew it would be off when I powered it up. And now that it's warmed up it's typical Fluke.

Now I'm really curious to see if it has ACV and Ohms options. Apparently according to GregDunn if the selector switch is blocked it doesn't. But I'll hold off opening it up until tomorrow. 
The thing I have found with Flukes is that they usually state on the rear panel where these things are optional extras, what options it left the factory with, have you checked the rear panel for the options list at all?
5

The DCV/ACV/Ohms selector switch is jammed solid. Can only select DCV. Will attempt to fix or again, take it off the 8800A parts unit.

The 8810 by default only came with a DCV capability, IIRC.  To enable ACV, Ω, etc. you have to not only have the appropriate card in the unit, but also remove a blocking tab in the switch assembly so that the other modes can be selected.  See sections 2-14, 607-7, and 608-5 in the 8810A manual...

Interesting. I didn't know that. So apparently this doesn't have ACV and Ohms capability. I haven't opened it up yet to take a look.

And here it is a few hours later after getting up to room temp. I haven't done anything other than that and it is absolutely bang on in spec.
Happy camper!  :-+



Once again......seems you can always trust a Fluke.  :-+ :-+


the far vertical board is the ac volts option.   the near board is the ohms option.


but yours has a much cleaner face than my old dog.......and mine did not come with a handle.


6
Test Equipment / Re: Test Equipment Anonymous (TEA) group therapy thread
« Last post by med6753 on Today at 09:05:05 am »


Yep, Flukes are really great in maintaining their specs. I have had over 9 flukes 25's and 27's all ex military with calibrations dates that were many years out of date and yet when I hooked them up to a standard AD584M and other good reference sources, all agreed with each other. I have since sold most of these now and have replaced them with more modern bench meters, the 8840A and 8842A and again both these were years away from a known calibration and yet they also agree with each other against my normal calibrations standards, once they have been given the requisite warm up period  :-+

This 8810A was frigid cold when I unpacked it. It only got up to about -12 C today. And it sat in a (probably unheated) UPS warehouse all weekend. So I knew it would be off when I powered it up. And now that it's warmed up it's typical Fluke.

Now I'm really curious to see if it has ACV and Ohms options. Apparently according to GregDunn if the selector switch is blocked it doesn't. But I'll hold off opening it up until tomorrow. 
7
Manufacturing & Assembly / Re: Pick & Place MachineTVM920
« Last post by zszabo on Today at 09:04:35 am »
Hi again,

Where can be fount the new nozzle holder ?

THX.
Z.
8
If I had the money, I´ll surely go for the R&S RTB 2004 - But I don´t and therefore I count on rigol for making their raw diamond to a shining one... ;)
By the way I did a request to rigol.eu for the first official firmware update, when it will be launched.
9
Manufacturing & Assembly / Re: Pick & Place MachineTVM920
« Last post by zszabo on Today at 09:03:17 am »
Hello,

Which version is Your software ?

THX.
Zoltan
10
Is there a way that Altium knows how to deal to the impedance of differnetial pairs.. I can see how to do it for single ended signals.

Pages: [1] 2 3 4 5 6 ... 10 Next