Show the homemade equipment you are using now.

[Edison]

I will also add one piece of quadruple voltmeter +/- 200V DC, the gauges are galvanically isolated and can thus be connected anywhere in the device under test, I haven't removed the protective film yet, because I don't have the anchor ready - so I don't scratch it.
I still have enough in stock, so I'll throw in something sometimes 🙂

[Edison]

Hi, there is nothing complicated about it, a regulation transformer is used at the input and a large toroid at the output - I needed another AC source and so I quickly built it from what I had at home, I originally thought about regulating the current, but in the end I didn't do it.

[Jester]

I'm using it this morning, 19bit AC/DC load, mostly use it in AC mode. 250V, 40A

[Edison]

Well used HP case, unfortunately these boxes do not fit deep into my workplace
👍 beautiful work 👍

[jasonRF]

This is a very simple low-voltage differential probe I made a while ago, mostly to use at audio frequencies, so is just built with a TL052 with some 0.1% 100k resistors.  I had it open today to check which op amp I used so decided to take a picture.  The front-panel switch is to engage a 40 kHz 2nd-order Butterworth low-pass filter (very useful when measuring outputs of some class-D amplifiers).  I measure 50+ dB CMRR in the audio band.  It frees up a channel on my 2-channel scopes, so is pretty useful.

jason

[Martin72]

Not in use now, but in progress:
Power inductor checker, inspired by:

http://elm-chan.org/works/lchk/report.html
I designed the board and made some changes, the first test showed that some improvements are still necessary.
When I have them on the way, a separate thread will follow.

[Aldo22]

My first, handmade, cheap adjustable power supply.   

[ccktek]

Latest addition to the brood:

Variable isolation transformer (2023) 

https://www.eevblog.com/forum/testgear/show-the-homemade-equipment-you-are-using-now/msg4498885/#msg4498885

[fable]

Here are some of the tools i have made and use every day

First picture from top to bottom
Dummy Load
PSU ac/dc
vacuum pump pickup tool
triple soldering iron controller

2.  PSU 2x24v 2A
3.  Soldering iron and desoldering gun controller
4. Differential probe

[KungFuJosh]

This is my vacuum tube curve tracer.

In my current unit, I added a step up converter for the heater voltage. Now I can run heater voltages at 20V easily (or higher, but I don't have any need for that).

[py-bb]

A bit of horror is inside.

I fully agree.

But totally worth posting - I learn a lot from just seeing how some of these are assembled.

Never be afraid to post a monstrosity, if we only posted perfection there would be no posts!

[Hexley]

This device tests batteries of various types -- button cell, AAA, AA, C, D, and N; coin cell lithium; and 9 volt packs. It supports battery chemistry of alkaline or NiMH types for most cells.

The knob selects the cell size and chemistry, then is clicked to start a load test with the appropriate current. The voltage under load is measured, and the display shows "New/Good/Weak/Dead" according to the corresponding voltage threshold. The estimated charge level is displayed, as is the voltage under load.

It is built around an adjustable current sink with a range of 10 uA to 200 mA, controlled by a small ARM Cortex processor that also handles the rotary encoder input and LCD output.

The battery holder is a "BF-2A", found on Banggood. Henrik Jensen (forum user HKJ) put me on to it.