What Electronic Projects are you working On

Following some discussion off-forum, it's apparent that large proportion of model engineers also dabble in electronics. Indeed, I know some of you are doing some very advanced stuff.

Some of these discussions (e.g. tachometers, inverters, DROs and CNC) have homes elsewhere on the forum, but this topic is intended for those who would like to discuss technical issues, without clogging up other topics for those who would rather be metal mangling

It can also be a home for build or development threads on electronic accessories, or for postings on techniques and tools - and naturally plenty of scope for questions.

We'll set the 'scope' for this topic according to people's interests, but I hope it's more about driving stepper motors than programming TV remote controls.

So. What are you up to with your soldering iron?

Neil

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Making a microphone pre amp at some point this weekend for use with my HF transceiver.

Nick (G7GPL)

Edited By Nick_G on 23/05/2014 14:59:47

Not truly electronics per se, but spent an hour removing the alarm from my motorcycle which had died due to a long term storage situation.

It would appear that the alarms internal battery is only good for about ten years and even less when you remove the bike battery for storage.

The solution from the alarm company? 'we can supply a replacement unit programmed to your key fobs for around £350'.

Don't you just love technology?

I got a handy meter from xxbay which was very handy when I dabbled, only 25 quid including postage

A vichy vc99

I am building an Arduino ECU for my '69 T100. It has several clever and unique features.

Derry.

PS well I hope it does by the time I finish it, I've been at it long enough!

I have two projects on at the moment. The first one is to add a tacho input to my Attiny4313 based interface for "Yuriy's Android tablet DRO" I have decided that using a separate microcontroller to handle the tacho function is the easiest way to do it. I plan to use a modified version of my 1 to 99 pulses per rev tachometer that I submitted to MEW several years ago. This will pass the data to the ATtiny which will then format it and pass it on to the Android tablet. The other project is a stepper motor controller to rotate one of the Wixey type angle gauges about 455 times. This is to check my theory that the reading will be incorrect after this number of revolutions. This controller will probably finish up driving a rotary table in a similar way to Tony Jeffree's Divisionmaster.

Les.

I have assembled most of the bits to create a DRO setup based on Yuri's Android DRO, but the bits are all in one of my "future project" boxes.

First I am going to build an X axis variable speed drive for the Mill. But I have seen some rather trick full speed return circuits for this which enable the table to quickly return after cutting ready to advance for the next cut. I am still agonising over this as it introduces yet more things to go wrong.

But it would be nice though.

graham.

Part way through a very basic interface (more of a connector really, or mainly) to control Denford Novamill stepper and spindle from PC parallel port without having to replace stepper drivers or DC spindle drive.

Sorry Jason, the bike is four years old, it was the point that if you remove the main battery for a few weeks the alarm 'dies' which is not mentioned in the manual. You can reprogramme it IF you can get the led to flash and input the code manually.

But as the battery was off for six months there was no way the alarm was going to talk to anyone.

The unit is a Thatcham alarm and I was advised that all the internals were potted and it was not possible to replace the internal battery.

I'm trying to get to grips with the Arduino. Hoping to use it as a basis for some control functions for my MkII Fifth scale model car:

http://www.amdengineer.com/mk-2-15-scale-rc-car/

possibly for an automatic gearbox, to control the lights, or even as an ECU for the engine! Endless possibilities!

Regards,

Alex

> The unit is a Thatcham alarm and I was advised that all the internals were potted and it was not possible to replace the internal battery.

They just means it's more bother to them than it's worth. The link below contains some adult language but is otherwise OK.

**LINK**

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My God, this guy deserves a medal as big as a dustbin lid.

Programming an Arduino to leak oil has gotta be a first ?

Don't do electronics once workshop weather arrives

When winter arrives, I have some radio's to repair / refurb Kenwood TS00G (blown PSU) Heathkit HW101, sideband oscillator crystals need setting correctly in the filter passband and then what to do with that old Pye basestation....

Steve

G0AIN

Not in the summer, but make my own battery powered loco speed controllers during the cold winter months. I would like to link up with others who do the same, to possible exchange ideas.

Hmmmm, not sure if I should reply to this thread as I don't 'dabble' in electronics, but do it professionally.

I have a couple of spare time projects on the go:

1) An electronic ignition system based around a M0 core ARM processor and an avalanche MOSFET. The aim is to eliminate the shortcomings of the simple Darlington transistor ignition systems and, most importantly, use an ignition coil that has a 10:1 winding ratio between secondary and primary. A home designed spark plug is also part of the equation.

2) A simple processor circuit with 'constant current' drives for white and red LEDs in lamps for my traction engines while simulating the intensity variations of an oil lamp.

Professionally I have at least half a dozen circuits in progress as well as mechanical design and 3D printing, but of course I am not at liberty to say what they are specifically. But I can pick out a few general sub-areas:

1) Isolated power supply 48V to 7.4V, at 2A, with isolated measurement of output voltage and current.

2) Circuit for accurate measurement of low currents, ie, a few nanoamps

3) Digitally controlled power supply from 0 to 10V at 500mA and which will follow a 1kHz control signal - current design uses less than half a square inch of PCB, just as well since there are eight PSUs per PCB

4) Several processor designs using a M4 ARM core processor with RMII interface to WiFi, SDcard, USB2.0, GPS and other interfaces

5) Lots of precision, better than 0.1%, digitally controlled analogue AC drive and sensing circuits

6) Lots of bogstandard switch-mode power supplies

7) And all the PCB layouts for the above - an interesting mix of switch-mode power supplies, digital signals in the tens to hundreds of MHz and precision low level analogue electronics all within an inch or two of each other.

The biggest problem with electronics today is that I can't see the darn components. Everything I do is surface mount and the components just keep getting smaller. That's why I am building 4" scale traction engines, at least I can see the parts.

Regards,

Andrew

Just received an Arduino Leonardo, as it can emulate a USB keyboard.

Just so that I can turn on myLinuxCNC powered CNC mill, and have a couple of buttons for homing, zeroing DRO, doing the spindle speed adjustments, etc.

I do have an MPG hand controller, but when doing things by manual methods, I find my keyboard/mouse setup inconvenient.

There are other ways of putting inputs into LinuxCNC, but this is one way, and I'll see how it goes.

(although I have a few Arduinos kicking around (make Lenz DCC controllers with them, amongst other things) the Leonardo allows me to mimic a USB keyboard)

JohnS.

G'day.

Redesigning my (over 30 years old) glowplug driver for more modern components such as a switchmode IC and FET output. With that in mind I downloaded LtSpice to model the circuit design, it's available from **LINK** - very good.

Also making an ignition coil winder to suit a small lathe, using an ex-baitcaster fishing reel level wind mechanism to distribute the turns.

Regards * Danny M *

Hi Andrew,
Here is a link to a design to generate a flickering candle effect that may give you some ideas for your LED oil lamps. The original design runs on a PIC12C508 but I made slight modifications for it to run on a PIC12F629 which I had in stock. The source code is very well documented so it should be easy to port to a different micro. I built the design many years ago and it comes out every Christmas. I will send you an email with the modified source code to run on the PIC12F629. (I have your email address from March 2011)

Les