Nightlight

Microproject this time, still waiting for a good projectile tube for the coilgun..

Either way, I got annoyed with not being able to see my analog clock at night and instead of choosing a sensible solution I decided to have a LED light it up.
At the same time that I have this low-current LED as light I don't want it to waste battery power by being on 24/7 so it needed some kind of on/off circuit.

First few ideas were based around the clock itself, to have it as a timer and manually set when to light and not, I quickly deemed this as unnecessarily complex for such a small project.

This lead me to the next, final, idea: Light control.
I'm using a phototransistor to 'measure' the light and then decide if the LED should be lit or not. The circuit got a draw of ~3mA(As far as I can measure with my budget multimeters) when lit and in the µA range when not lit, this should give quite a good battery life even on AAA batteries.

The entire circuit consists of 5 resistors, 2 transistors and a phototransistor and has so far been tested on breadboard and in Proteus. I'll solder this together whenever the mood strikes me.

Here's a schematic 'til I get it soldered together.

Coilgun, 2 stage, ~400J aka V2b

Time for my first 'real' 2 stage coilgun I guess. First stage will be switched manually with a microswitch+SCR whilst the second stage will have an optical trigger.

2x3300µF caps with max 350V, planning to charge them to ~315.

So far it's just a pile of shit since I'm still looking for a suitable barrel, unlike my older coilguns I'm downsizing the projectile this time. Planning to have 9-11mm diameter projectiles.

Here's a little clip of the pictured optical triggering circuit and one of the SCR assemblies being used on another coilgun, that one has a inner diameter of 14mm and a 12mm diameter projectile weighing in at around 40 grams.

 You can also check this clip out on my youtube:  Click me!

Cellphone holder, again.

I figured the plywood wouldn't really last at all if it started raining, especially since my bike is 'stored' outside and I'm WAY too lazy to remove it everytime I go in after a ride.

So I changed materials, this time it's up to plexiglas and PC to show what they can do.

I might add that cutting the plexi without proper tools was a complete pain in the arse...
This version holds the phone quite snuggly too but I chose to add the rubberbands for those "just in case" scenarios.
Comes complete with a clamp for wherever you'd want to clamp this.

Welcome back...

With a renewed interest for electronics and the funding to back it up I've decided to relaunch this blog. Hopefully it'll give some people a good read and a good way for me to write down what I do.

I'll start this out with a totally electronics-unrelated project. A cellphone holder for my bicycle so I can watch the GPS/Tracker stats while biking.

Made mostly out of 2mm plywood, holds the phone quite snuggly so it won't fall out, just for safety I'll most likely use a rubberband around it to secure the phone.


'til next time...