Fancies are expensive!

Going in and out of the bus at night I had fastened a Harbor Freight LED light that ran off a paid of AA batteries. Well, that light had a horrible attachment and kept falling down. The velcro never worked. The magnets fell off the light so it was more often than not on the ground. Thus, since I have several LED marker lights that are of no earthly use to me I decided to replace the flimsy Harbor Freight thing that seems to have fallen off yet again and this time vanished with LED marker lights. 

Cue a decision - whether to run them off the solar door lock circuit or from the AA door lock circuit. Running them off the latter would run the risk of flattening the door lock batteries so the idea was to upgrade from AA to D cells, particularly since the AA cells struggle in cold weather. That led to another question of how to stop the light from shining if I forgot and left it running. For that I looked on eBay and found something called a time delay relay. That sounded promising so I forked out $10 and bought one. 

The relay arrived with no instructions so I had to work it out. It seems that after placing it on its little pedestal that on one end there are 4 contacts. The set at the front were two pairs. One pair was to operate the relay and the timer. The other pair supplied power. On the back were 4 contacts - the bottom pair fed through from the relay when the relay was not activated. The other pair fed through when it was activated. A dial on the top set the time delay though the time delay seemed a bit off.

I connected the relay to a pushbutton switch that I had not realised was a latching pushbutton switch. That's actually useful to have! I connected an amber marker light to one pair of relay outputs and a red to the other.

In this picture, the button has been pushed but the relay has not yet tripped so the amer light is lit.

In this picture the relay has tripped so the amber went out and the red light came out. That all looks fine and dandy but brings me no closer to having my light turn out after a moment or so. While the relay does trip to switch the amber it, it leaves the relay powered and burning up electricity. What therefore would be needed is an extra relay to cut power. That's when it all begins to burn up yet more money and get far more complicated than just putting in an ordinary flippy switch and remembering to turn the light off!

The D cell battery holders I have will work just fine. The only issue with them is that the batteries need to be held in or vehicle motion might jog them free. This does not happen with the smaller lighter AA batteries. As I have AA batteries in situ I might as well add D cell holders and run the door lock of D cells and the LED lighting off AA cells. That, to me, would make far more sense. Due to limited real-estate behind the wall and due to the thinness of the OSB I might have to put a 3/4 plywood panel up that's attached to the OSB that just holds the batteries. This needs some thought. 

Meanwhile I angled my solar-collecting water heater and set it all going. I'll have to see if after a few hours the water is warmer. I suspect it won't be but who knows. There is a warming ray of sunshine out there. In the sun it's not bad. Out of the sun it's a little chilly. The temperature is 54F outside now. Maybe if I can find my infrared thermometer I can tell whether the water is warmer than ambient temperature or not.

In other news, I have been hunting in vain for another cheap CD-R unit. I bought the pair I have on eBay a few years ago and could not find another unit. Fortunately I still have the packet it came it. Sometimes it pays to be untidy and not to throw out packaging.

Looking up SKU S1169EU found ONE listing from somewhere called KKMoon that led to a non-existent Amazon webpage. That wasn't very helpful!

The back of the package shows how good this device is. Sure the video quality might be a little rough and ready but for recording traffic incidents it's absolutely perfect. I don't need to read number plates. Even if a car screams through a real school bus stop sign and the plate number is recorded and reported by the driver, nothing ever happens. In the event of an accident the police still don't give a hoot so there's still no point in recording number plates. They only take a mild interest if there's a fatality. However for shaming drivers by publishing their bad driving on YouTube, the quality is just fine.

There's the bar code. Again, the bar code got me precisely nowhere. All I can assume is somebody in a grass hut in the middle of Peking knocked a few of these out with their soldering iron, sold enough of them to be able to afford a supply of opium and then quit making them.

They are handy and they were cheap. All I needed was to add a video camera like this and the quality of the video was sufficient. 

So, I shall quaff more tea and maybe scarf some cake. Then I will head back outside and look again at installing a D cell battery holder screwed to some plywood that I can then fasten a gate to, to stop the batteries just falling out. That will allow me to put the D cells to power the door and the AAs to power the light. It is far more likely that I'll forget to turn my light off than for the door lock to wear the batteries out. Given the time a set of AAs lasts, a set of D cells should last a year.