Monday, 26 September 2011

Six Inches - Big Enough

I got around to taking the screen out of one of the LCD units to see what could be done with it. For a start the actual screen is 6.2" (according to the serial number and a ruler) not 7" as on the manufacturer's website, but that's no bad thing. It turns out a 6.2" screen is just the right size to fit in a double-DIN car radio slot, which prompts all sorts of ideas.

It also turned out that there were 2 circuit boards, a big one with an audio amplifier and some power supply circuitry and a small one for the actual screen. Essentially the screen will operate with just a 4-wire connection (9 volt, GND, Video and Video GND). There is another connector for options (screen mode, colour and brightness), but with nothing connected to this the monitor defaults to perfectly use-able settings.

In the photo I have it hooked to a PC via a VGA-to-Video adaptor. The computer is running Tiny Core Linux (my new favourite distro) in 640 x 480 mode (I think). It will go down to 320 x 240 which gives huge icons that would be great with a touch screen.

The wallpaper is Pink Floyd's 'Animals' album cover, recently re-created over Battersea Power Station - "Every Dog needs a home, a shelter from Pigs on the wing."

Tuesday, 13 September 2011

DIY Immersion Heater Control

This started life as a plug-in countdown timer I got in a clearance sale at CPC.

After taking it apart and removing the 13-amp plug and socket parts I was left with a the guts of an immersion heater timer that can be set between 5 and 50 minutes in 5-minute steps . The relay was rated for 20A at 240V so it could certainly handle the heater current, so I set about blanking off the hole where the socket was and then glued the back of the timer to a standard blanking plate with Araldite. I drilled a hole through the middle of the blanking plate, added a 3-way terminal block and voilá, an immersion timer for less than £5 to compliment my £5 central heating timer. Now there is no danger of the immersion heater being left on for more than 50 minutes and if you need hot water for washing dishes that's just one press.