lbenson
Senior Member
I would like to develop a power control system for an unattended house monitor using picaxe and simplelan where it is possible that the power will be out for a long time--days or weeks--while the cable providing internet access may be available. I plan to use a UPS system (550VA/330W) to keep the picaxe, cable modem, and router running, but the cable modem and router draw about 13 watts and could draw down the UPS if left on all the time. In the event the UPS signals that power has been withdrawn, I would like to use the picaxe to shut off power to the cable modem and router except for a brief period once a day when an update email would be sent via the simplelan.
I would like to use the Sharp S101S02 Solid State Relay ($3.95 from Jameco), switched on with a BC547 transistor, to control the power to the cable modem and router (always on when there is power to the UPS, and only off when the power has been off for, say, 5 minutes). It is possible that there would need to be two SSRs, with the cable modem turned on first, and then the router a minute or two later.
Is this a reasonable way to do this? Is there a better way? How should the SSR be packaged for greatest safety?
I would like to use the Sharp S101S02 Solid State Relay ($3.95 from Jameco), switched on with a BC547 transistor, to control the power to the cable modem and router (always on when there is power to the UPS, and only off when the power has been off for, say, 5 minutes). It is possible that there would need to be two SSRs, with the cable modem turned on first, and then the router a minute or two later.
Is this a reasonable way to do this? Is there a better way? How should the SSR be packaged for greatest safety?
Code:
--Mains
|
UPS-----------------------------------.
| |
o--9V DC wall wart--regulated 5V--picaxe----------------------.
| | |
| BC547C transistor |
| | |
o------------------------------------SSR----o---Cable modem |
| = |
o---router====simplelan