Recent Posts

1

Repair / Re: Simpson 269, should I be pissed or excited?

« Last post by coromonadalix on Today at 05:00:43 pm »

the board from @OP  seems blank, non operational ?? missing parts ....   ie: voltage dividers etc ....

2

Beginners / Re: Why my battery charger not charging powerbank and other electronics?

« Last post by MrAl on Today at 04:58:52 pm »

Hey, thanks for the answer, I really think you right about communication between phone and charger, because that was my first guess after i tried different cables and chargers, is there any way to force it to work? I heard something about charging triggers
Update:
I found that this charging triggers exist: 5V 9V 15V 20V PD QC AFC Fast Charge Decoy Trigger is one of them

Hello,

Yes, there is a device they call a trigger, but you have to be very careful with them.  That's because if you set it for 12 volts and your device to be charged only takes 5 volts, you could easily blow out the charging capability of the device or even the entire device might blow out.

You could try measuring the output of your power bank see if it puts out 5v.  I think most of them do so it could also be something else preventing the charging to take place.
They make connectors with wires on them so you can measure USB outputs, as long as they are capable of doing that without communication with any device.  They make nice power meters that measure voltage, current, power, other stuff too, that are not too expensive.  You connect it between your power bank and the device to be charged and it gives a continuous readout of voltage and current at the very least.  Very good to have when you have devices you want to charge.  Even if the device is charging ok you can then check to see how well it is charging.

3

Repair / Re: Keithley 190 Nixie DMM resto... waxy "Tropical Fish" caps & crusty switch help

« Last post by coromonadalix on Today at 04:56:30 pm »

thoses switches can be dismantled  but you need to fully isolate them mechanically, dismantling any metal braces who connect them  where the spring is located, and you may have a small formed metal part who act as the lock and release pin ....

lots of work, i would not do that,   use  contact cleaners / deoxit  .....

4

Microcontrollers / Re: STM 32F4 FPU registers and main() gotcha

« Last post by harerod on Today at 04:54:18 pm »

... Those registers are unlikely to be accessible if the FPU is not enabled (same with SPI etc etc). ...

Which is implied in the footnotes of the article you linked in your initial post: http://www.efton.sk/STM32/gotcha/g203.html
The FPU seems to be no different from any other peripheral on the STM32 - enable before first access. This may require a combination of power and clock.
I haven't used the STM32F4 FPU in such a long time, although I designed heaps of devices based on that MCU. During the first tests I wrote setup routines based on the datasheet.
This may have been before CooCox and Atollic became available. Where have the last ten years gone?

5

Test Equipment / Re: Agilent U1272a strange zero readings in AC measurement mode

« Last post by coromonadalix on Today at 04:52:14 pm »

with leads disconneted, if so they act as antenna and pick anything in the air,  induction etc ...   

if you remove them  is the meter show less ... 

some brands  will force a zero value ... 

the fluke and amprobe i have at my job  don't show zero value, disconnected leads

nothing to worries about   

6

Repair / Re: Simpson 269, should I be pissed or excited?

« Last post by Mike De on Today at 04:51:43 pm »

I know this post is old but looking for the small 15 tooth sprocket for the selector chain. Anyone know where to find this sprocket?

Thanks for your help

7

Metrology / Re: Anyone have an original Fluke 5200A extender card

« Last post by Bill158 on Today at 04:46:23 pm »

UPDATE: Peering into the photos a bit, I can see that they use "turrets" for the pins to enable you to hook onto signals - Very helpful.

TonyG

Tony:
In looking at the extender board I now see that FLUKE did indeed include very short "turrets" for hooking probes onto the connector for the raised board to be tested.  I never noticed that before, but then like I said I have never had a need to use this extender.  I saw it on ebay once and grabbed it.  It came with two SMB to SMB cables with SMB to BNC connectors, 2X SMB to male BNC and 2X SMB to female BNC, also.  It is the complete 5200A service kit as far as I can tell.
I took these pictures originally for "RAX" on EEVBLOG (Radu Dicher) about 1 1/2 years ago.  He was working on a 5200A that he got.  He was going to layout an extender board but I don't know if he ever got that project completed.
One other dimension of this board, it is 0.195" thick which follows as with the main board with the traces and then the two "covering" blank safety panels the PCBs are 0.065" thick each.

Bill

8

Beginners / Re: Why my battery charger not charging powerbank and other electronics?

« Last post by DiDBoGDaN on Today at 04:45:15 pm »

the inscription on my power bank: input 5 V 2 A (max.)
also i know my charger doesn't have fast charge function but that's not really a problem i'm just trying to use this new charger for my other project and it doesn't work but it doesn't matter now thanks for the replies

9

Test Equipment / Agilent U1272a strange zero readings in AC measurement mode

« Last post by Yuriy V. on Today at 04:44:24 pm »

Agilent U1272a strange zero readings in AC measurement mode. And the same for AC voltage modes.
Has anyone encountered such a problem?

10

Repair / Re: Does anybody know what this component is?

« Last post by coromonadalix on Today at 04:42:52 pm »

if i recall  ferrite bead   but 5 in line  instead of single one

with an ohm-meter  you should not read anything from the nearby pins, but only in front

see attached picture of a 4x


https://www.tradeindia.com/products/ferrite-bead-for-multi-line-suppression-c5060940.html