Part 2 - Pophole Controller – Parts list for part (a) - Electrical controller. In this post I’m going to list the parts we will need to buy (not counting consumables) however I’d just caution that you read through all these posts (and subsequent ones) before you go and spend your hard eared cash. You need to be confident you can fit them to your house before you splash out. Sorry this is going to be a large post so I’ll split it into two covering the two parts of the design.
1 Electrical Controller2 off 12Vdc regulated plug top power supply. Power rating 2 Amps (25Watts) minimum.
1 off digitally programmable mains timer. – for plugging into the timer. If it mechanically won’t fit (interferes with the programming buttons) you may need a short mains extender which will plug into the timer.
1 off 3pole screw terminal strip. Ie a strip with at least 3 three screw terminals (poles)
Mains cable 1.5sqmm 5A twin & earth as used on lighting circuits is suitable. The length will depend on how far your mains socket is away from the house. Scrap `reclaimed mains cable is OK for this application as it will only be carrying 12V at about 500mA current.
Sourcing12Vdc regulated power supply – many suitable units are available on ebay some which are advertised for CCTV applications however you don’t want the dc adapter types with multiple output voltages and connectors or units intended for battery charger applications. You can either use the plug top type units which are enclosed in a moulded box with the usual three mains pins for plugging directly into a mains socket or you can get a “rat in a snake” type PSU often used for pc laptops with a mains lead and dc lead. Often the latter can be obtained used very cheaply as they are ex laptop units. For example
LINK which is an ideal high spec device with high output current and has fully protected outputs for £10 including postage. It doesn’t have an output connector but marked output wires which is ideal for this application as you don’t need a connector because we’ll be using the bare wires, Also the wires are identified so avoiding the need to check them with a meter. If you can get such a PSU like this cheaply go for it. Although it should be 12V nominally any regulated supply from 11 to 14Volts at 2Amps will do.
Here’s another suitable ebay unit
LINK but not so well spec’d.
The above are circa £10 including postage
See pictures
Although I’ve said you need 2 of these 12V supplies in fact only 1 needs to be 2amps and the other could be a cheaper lower current unit, a minimum of 100ma is all that is required. A typical lower current plug top unit would be circa £5
For the more technically minded the main 12V supply to the aerial could be provided by a car battery with an attached battery charger if you happen to have these available for free.
Digitally programmable mains timer – normal domestic types are suitable these are available on ebay, IKEA or from most supermarkets. Prices range from circa £5 to £9 depending on source. Most of these have far more features than we need such as random switching and different programmes each day but this doesn’t effect price. You need to only set up 1 programme with an ON period during the hours of darkness when you need the door shut. Instructions on using these are included with them just remember to programme on at dusk and off at dawn EVERY DAY of the week. I’ve said a digital timer but a 24hr mechanical one is also suitable though less accurate over time. This is an example of a couple of suitable ones
LINK and another
LINK Terminal strip is available from any DIY store,
www.screwfix.com or
www.rapidonline.com. 5A small terminals are suitable electrically but i’d suggest you get the more chunky 10/13A ones which are easier mechanically to handle and terminate.
Large crocodile clip the type used on battery chargers available from Rapidonline .com (they do a cheap 80p ish one or you can use one sold as an electric fence accessory from farm shops or equine suppliers (£2 ish.) Fully shrouded ones are best but more expensive.
Mains cable If you need to buy mains cable any DIY store or on line from www.screwfix.com www.rapidonline.com or ebay . £16.50 + delivery from screwfix for 50mtrs
In the next post I'll cover the door actuator (aerial) parts.
Bye for now.
HF