Safe power supply for multiple devices - Page 1
Forum section: electronics / beginners

author: GBarron
author_rank: Newbie
timestamp: June 01, 2012, 02:39:39 pm
content: I'm building a bed for my daughter and I'm locating all of the ugly gadgets under the bed (Set top box, XBox, Blu-ray player, etc). I have designed an infrared learning circuit so the bed can "learn" the remote codes for the different devices and everything will be controlled by a single device. At this point I'm thinking a bluetooth smart controller like Android or an iPod.The issue I have is that I'm not experienced enough to mess with mains electricity and I would like to switch the consumer devices on and off from an MCU running at 5v. I would like to send a small signal to a relay of some sort to switch on a device and if the signal is not there I would like to power the device off. To give you an example if I select the DVD player I would switch on the DVD player and the TV. If I "switch the bed off" I would power down everything except devices that need to remain in standby such as the cable recording PVR.Do you know of a safe circuit I could use or somewhere I could buy a black box off the shelf to individually control power to the devices. I'm in the UK so international suppliers are ok and eBay of course. Basically any suggestions welcome.Thanks in advance.

author: david77
author_rank: Frequent Contributor
timestamp: June 01, 2012, 02:57:54 pm
content: I'm not sure if this is what you're looking for.http://www.ansmann.de/cms/consumroot/accessories/energy-saving-mains-timers/aes2.htmlIt basically switches on the 230V socket the moment it receives any IR light. The socket stays powered for 1 hour and then switches off again. This is mainly intended for TV's and people who are prone to nod off in front of the telly.I've used this for some time now and it's brilliant. At first it takes some getting used to, because you have to press buttons on your remote from time to time to keep it active but that's something that hardly matters in practice it turns out.Apparently it's also available with UK plugs.

author: GBarron
author_rank: Newbie
timestamp: June 01, 2012, 03:00:16 pm
content: It's a similar concept, but I want to control 4 or more devices individually using a single mains power supply if that's possible.

author: GBarron
author_rank: Newbie
timestamp: June 01, 2012, 03:04:00 pm
content: I was thinking of something like this, but I can't tell if this is safe for use as a mains relayhttp://www.ebay.co.uk/itm/170745298865?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2648#ht_4062wt_1413

author: david77
author_rank: Frequent Contributor
timestamp: June 01, 2012, 03:22:59 pm
content: Ah, a misunderstanding.You could get a set of remote controlled sockets and connect your MCU to the remote control. Just put a small relay or a transistor parallel to the buttons. Complete isolation is guaranteed. Only slight drawback is you'll probably have to replace the battery from time to time, although you may be able to supply the remote from your MCU board, too.

author: saturation
author_rank: Super Contributor
timestamp: June 01, 2012, 03:39:44 pm
content: Except for the custom IR stuff you have on the bed, what can work is a home automation system, the oldest being the X10. You'll have to find what is recommended for your country. X10 sends control signals from a controller over the power lines to plug in modules, each hard wired to respond to a code. Its been around for ~ 30 years, stable technology, but read more or ask about its pros and cons. The modern versions are RF based, are more secure and can take more devices.http://en.wikipedia.org/wiki/X10_%28industry_standard%29On the Intermatic, its only one vendor of this type. There are others with better features, or less cost.http://www.amazon.com/Intermatic-HA101K-Home-Settings-Wireless/dp/B000BRMMDU/ref=cm_cr_pr_product_topA reason for changing and not using your MCU DIY system is to insure you build a system with state code rated electrical safety considerations. If you are sure you can meet those with a DIY, by all means.

author: GBarron
author_rank: Newbie
timestamp: June 09, 2012, 07:03:54 am
content: Thanks for the feedback. I decided to go with an off the shelf solution for safety, but wanted to make sure it would fit within my solution. Thanks to the posts here I discovered remote controlled power plugsI didn't know they even existed, but now I have them they fit very easily in to my solution. Onwards and upwards.