Pages: [1]   Go Down
Author Topic: Tiny 240/120V AC power supply for logic device  (Read 2520 times)
0 Members and 1 Guest are viewing this topic.
South Africa
Offline Offline
Newbie
*
Karma: 0
Posts: 7
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Has anyone seen or heard of an onboard switch-mode power supply circuit that could supply 5v at around 50mA? I have a lot of projects in mind that could benefit from a very small and very cheap mains power supply incorporated into the board. This would eliminate the need to run low voltage wiring in distributed control systems. For example home automation where you want to mount a XBee chip in behind a light switch. The problem is always the power supply to run the logic device. Something to run the logic device and a optocoupler or two would only need around 50mA. Does anyone with experience in switch-mode power supplies have any thoughts on this?
Logged

Global Moderator
Boston area, metrowest
Offline Offline
Brattain Member
*****
Karma: 518
Posts: 26344
Author of "Arduino for Teens". Available for Design & Build services. Now with Unlimited Eagle board sizes!
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

Yes, Mouser.com carries such animals.
example:
3.3V for xbee
http://www.mouser.com/ProductDetail/RECOM-Power/RAC01-33SC/?qs=sGAEpiMZZMsuBfEaN9EhVc2YZ4jw9niG
5V for 'regular' logic
http://www.mouser.com/ProductDetail/RECOM-Power/RAC01-05SC/?qs=sGAEpiMZZMsuBfEaN9EhVVuZwUusrdb%2f
Logged

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Ontario
Offline Offline
God Member
*****
Karma: 24
Posts: 860
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

The approach used here might be cheaper, but is definitely more fussy and I would guess that 50mA would be at the high end of what it could supply.  It's also as dangerous as hell to work on.  Have a look at the last diagram and surrounding discussion on this page:
http://www.mhennessy2.f9.co.uk/gainclone/control.htm

Logged

Offline Offline
Sr. Member
****
Karma: 6
Posts: 427
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Wow, talk about interfacing to the national grid!, that`s one circuit I`ll never use!   smiley-lol
Logged

South Africa
Offline Offline
Newbie
*
Karma: 0
Posts: 7
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Thanks Gardner for the circuit. This is exactly the kind of thing i am looking for.
Also thanks Crossroads, the mouser parts are probably easier for prototyping. Think I'm going to get a few of them!
C'mon Lakes! Try it sometime! A 240v whack is usually always your own fault. Only in very rare cases does it stop your heart  smiley-lol
Logged

Pages: [1]   Go Up
Jump to: