Recent Posts

1

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by KungFuJosh on Today at 04:51:12 pm »

I don't see why other hacks are lesser hacks though.

As you know, I hate Rigol...but in this case, the hacking sounds fun, and actually made me consider it for a second. 😉

2

Microcontrollers / Re: Signal filtering - Could this work ?

« Last post by gf on Today at 04:51:03 pm »

The CIC filter already does the moving average ?

A CIC filter is just a particular way to implement a 1st order or higher¹⁾ order moving average filter. A CIC structure is particularly useful in combination with down- or up-sampling.

This would be my approach (untested!!!): https://godbolt.org/z/dWPabE8Ea

3

Test Equipment / Re: DMM Input Capacitance

« Last post by KungFuJosh on Today at 04:49:02 pm »

What's your test setup for this? How are you referencing ground?

Thanks,
Josh

4

Microcontrollers / Re: Dim OLED Screen replacement for Agilent Keysight U1253A U1253B U1273A U1273AX

« Last post by onesystem on Today at 04:48:31 pm »

You can make an optic cable for sure, it is actually quite simple circuitry. Do you by chance have a 3D printer? that would be needed to print out a snap-in head that would align the LEDs of the UART with meter LEDs. I can throw together a printable file and a circuit board quickly if you are interested.

If it is a bit too involved, then what can be done is to use regular FTDI UART usb cable/dongle and connect directly to the meter internal header (which is definitely present in U1273AX on the top right of the board. Not sure where it is in 1253A

5

Projects, Designs, and Technical Stuff / Re: USB C routing: Will this work?

« Last post by jkostb on Today at 04:39:49 pm »

Do you have a ground reference plane below the USB signals? I don't see this. USB signals should be routed as differential pair controlled impedance lines. So you need a ground reference plane below. Also the ground pour besides the USB signals changes the controlled impedance. I still see a lot of layouts where the top and bottom layers are poured with ground. Often without stitching vias. People think that it will help against EMI issues and signal integrity. The contrary is the case.

6

Projects, Designs, and Technical Stuff / Re: role of optocoupler for biasing drain of amplifiers

« Last post by xvr on Today at 04:38:04 pm »

Yes, connection is right, but result is very strange
Low pin of V1 should be connected to MOSFET source as well.
Try to add small resistor in gate of MOSFET (20 Ohm will be enough)

7

Projects, Designs, and Technical Stuff / Re: Need help with _ _ _ schematic review _ _ _ for solar & supercap powered sensor

« Last post by Peabody on Today at 04:37:58 pm »

What does R2 do?

8

Projects, Designs, and Technical Stuff / Re: 120V AC power path for solar charge controller

« Last post by davegravy on Today at 04:36:38 pm »

Thanks, ok I'm going to try this.

I thought of another possible issue, since it looks like in this scheme both sources can be pushing current simultaneously.  The panels are rated to 50W, the AC brick is 60W, and the Genasun is 65W. Should I implement some form of limiting to prevent overloading the Genasun?

9

Projects, Designs, and Technical Stuff / Re: role of optocoupler for biasing drain of amplifiers

« Last post by john23 on Today at 04:33:25 pm »

Hello XVR, I have tried to connect other mosfet but connecting VSS as you said just gives me very bad gliching result.
A schematics is shown below is it the proper way i should connect the driver to a mosfet?
Thanks.

10

General Technical Chat / Re: Watches lovers

« Last post by AVGresponding on Today at 04:28:47 pm »

Can anyone shed any light on the brand "Gervaux"? I recently acquired a wristwatch, and there doesn't seem to be much in the way of information out there.