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:

AE EP#39 Sequencial Motor Controller Prototype

Finally it seems I made something actually useful 😀 This board is to control my fathers vinegar machine.
I provides him with an easy to use interface to set a sequence of up to 4 motors to control vinegar and air pumps. But be warned, this is a prototype – not the final design. For now the buttons’ response is hell and save/load/reset functions are not implemented. It is based on an atmega168 from avr but I think the final version could go down to an atmega88 (~5k flash in use now). Enjoy the video:

Here is my first draft >>>WARNING this is NOT the board, just my first idea!!!<<< the concepts are there, all pinouts can be derived from the software. There will be a nice schematic in v1.0! sequenzer
The software:

Have fun!

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 voilà 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#28 DC Motor Speed Control PWM Style

When I gave myself a little treat (a pack full of scrap electronics for €5) I found a complete DC motor speed controller Kit inside. So I built it up and show how this pwm thing works.

The trick here is, to not control the motor speed by using a lower voltage and therefore putting in less power continuously but to slice up the motors energy input into chunks. That will let the motor run even at lower speeds whilst letting it keep most of its torque. Pictures say more than a thousand words, so watch the vid:

Edit: here are the links to where I got it and the building instructions: Bausatz Drehzahlsteller für Gleichstrommotoren and instructuions. Mine was in this pack.

AE EP#26 The Ultimate Breadboard

While I was working on my Oscilloscope project I discovered, that breadboards are only semi-useful for Bigger things. Everything seems not to add to your project but to just pile up on it. After you added some probes and things that need a bus you will sit on a fragile, unforgiving crapstack, that just waits for you to stick a jumper-wire in the wrong hole. So I decided to make myself some room on the board and push connectors, displays and meters away from the center. Just take a look what came out:
Breadboard in a pic

check out the vid to get a walkthrough

So here is a little list what it includes:

* 2 max 232 Level converters
* An arduino NG
* 3 BNC connectors
* 8 banana Plugs
* A 50 V voltmeter
* Tiny tiny breadboard for displays and button stuff
* 4×7-segment display with driving transistors
* Datavision DV-20208 HD44780 compatible LC-display
* 2x lm3914 bar-graph displays with jumper selectable voltage range
* Avr-Net-IO for some Ethernet
* A -10V -5V GND +5V +10V earth 0V 35V Power supply
* and of course a humongous breadboarding area

This is of course just a source of ideas so if you make one of your own please let me know and if you don’t publish yourself, I’d be delighted to show off pictures of yours here!

Some words on construction:
The base is made from a piece of structured plastic (45 x 30 cm) on top of that are some pieces of wood with some plastic veneer that form the body. This makes up the wedge form in the back. On top once again I used some sign plastic covered with red spraypaint, why red? because its shiny 🙂
Ground and Earth are normally separated and can be connected on demand.

List of inspiration and components the Voltmeter was in this pack: Einbau-Meßgeräte-Sortiment 10 verschiedene, Volt- und Ampermeter und Hz-Messer

Here is a little zipfile containing the PSU-design and the VU-meter: PSU_LM3914

PS.: the space above the tiny breadboard is reserved for some raspberry-pi…