Recent Posts

1

RF, Microwave, Ham Radio / Re: 120 or 125 ohm coax

« Last post by T3sl4co1l on Today at 05:02:35 pm »

Next option might be: run regular coax all the way through, then put an LC network at the tip of the arm, of equivalent Zo and electrical length (Fo).  Equivalent (calculated) values should be close enough that VSWR is okay, but this does of course get dangerously close to "eh just put a matching network on it" and then you need a VNA (well, some manner of NA) to be sure.

Tim

2

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

« Last post by doru.cazan on Today at 05:01:46 pm »

Hi @Peabody, not really sure, it is part of the Hackaday.io project design, link in 1st post. My best guess is that it helps limiting the supercapacitor charging current to even a lower value (30mA when the solar panel outputs 6V) compared to the shunt regulator capabilities, that can sink more than 60mA (according to the data-sheet max 100mA).

3

Repair / Re: Sony J30 PSU repair

« Last post by Harry_22 on Today at 04:58:19 pm »

Please check following parts and measure the voltage.
What is the left one?

4

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

« Last post by xvr on Today at 04:57:44 pm »

Power amplifier supply voltage has no relation to connection of V1. It will be defined by V5

BTW. Why not use P channel MOSFET? All isolated drivers and floating power supplies will gone avay.

5

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

« Last post by DavidAlfa on Today at 04:57:00 pm »

No, the internal header is a different port, I don't think it's "talkative"?

6

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

« Last post by john23 on Today at 04:55:38 pm »

Hello , the problem is that i dont know the exact power amplifier TGA2590 drain voltage if we connect it this way.
I need exactly 20V to know how it by the datasheet.

7

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

« Last post by Peabody on Today at 04:53:53 pm »

I don't think either source will be "pushing" current.  I think the Genasun will draw what it needs.  But the Gensun should be able to handle the maximum voltage the panel can reach.

8

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. 😉

9

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

10

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