AE EP#47 Raspberry First Steps

Sooo, I finallly got around setting up my raspberry, nothing too special but maybe it helps some people.

The thing with the screen was rather easily resolved (if only I could have been able to see something :).

It involves pretty much tinkering and the trapezoid picture of the tube didn’t help.
In the end I added to the /boot/config.txt file to this:

overscan_left=18
overscan_left=10
overscan_left=-1
overscan_left=-25

The framebuffer_width/height are set back to normal.

AE EP#44 Simple Electronic Dummy Load

Several years ago Dave Jones posted a vid about a very simple current sink and I wasn’t too successful replicating it then on prototyping board and went on to make one a little different. lately I wanted to go back and do it properly this time to test the mini-psu’s and the sources on my broken Tektronix 2236. I think it became a neat little build and plan to expand on it putting it into the multi module case with some atmega and 7-segment displays. Here is the vid:

A zip file containing everything is here: DC_load

The rendering of the Design…
board_render_cut
…and the real version:
IMG_5671

whoop whoop

AE EP#40 Not Quite An Insulation Transformer

So I put the old insulation transformers case to retirement and put it into this new space-saving case to fit my bench perfectly besides the old Heathkit VTVM. I can just repeat my warning: THIS IS NOT legally an insulation transformer! I do NOT use it to be able to touch its output, I only use it as a current limiter on newly built circuits. So enough for the legal crap, enjoy the video:

C1-94 BNC Adapter

So my Tek 2236 grew some problems in the Display control section. Luckily I stumbled across a Russian C1-.94 (speak S1-94) with some DIN-5 Plug for input. I asked the guys on Fingers’ Forum for help and voilĂ  some parts out of the grab box and my adapter is ready:

Here I still ha a little GND connection problem, fixed now (the C1-94 is floating atm, I’ll replace the old calble asap)

Thanks again shpank, Henning and Reutron!

AE EP#33 Very Simple HV-genertation Jig

Ready for some Spitzensparken?

So currently I’m testing several different approaches on generating the HV for the scope project. This is my favourite for it’s simplicity. The schematic is Here:

Be sure to use a very good cap, that can withstand the hight currents when discharging. The parts are not critical, any transistor, that can handle the power will do and the resistor values are just for orientation.

Have fun watching!

The whole arrangement will make a top voltage of about 400 V with two secodaries at 24 V, you can go muuuuuuuch higher with lower values and resistor values. In my very first tesla-coil almost the same arrangement makes somewhat 4 KV.

Here came my inspiration from.

See you then!