L
logjam
- Jan 1, 1970
- 0
I want to switch 120/240vAC in a project with a panel mounted toggle
switch. I do not want any electric shock hazard from touching the
switch terminals.
I've looked at the solid state relays like the D2W202F triac based
relay.
http://www.crydom.com/userResources/productFamilies/7/crydom_d2w.pdf
They list a typical current of 3ma to turn on the relay with 5vDC. I
don't know how much the current will change with 28v being used to
switch the relay.
What I was thinking about was a bridge connected directly to 120/240vAC
and then a 5.1v zener diode/resistor regulator. Probably at the output
of this small circuit board would be an additional resistor to limit
the current at 5v to 10ma?
So from quick math it seems like this solution would waste around
2.5-3W at 240vAC all the time?
Are there any other solutions any of you could think of that would be
better than this?
For safety, I was imaging an input fuse of .1A and using maybe 3-4
zeners. They are cheap enough. If something were to go wrong the fuse
should blow first.
Thanks,
Grant
switch. I do not want any electric shock hazard from touching the
switch terminals.
I've looked at the solid state relays like the D2W202F triac based
relay.
http://www.crydom.com/userResources/productFamilies/7/crydom_d2w.pdf
They list a typical current of 3ma to turn on the relay with 5vDC. I
don't know how much the current will change with 28v being used to
switch the relay.
What I was thinking about was a bridge connected directly to 120/240vAC
and then a 5.1v zener diode/resistor regulator. Probably at the output
of this small circuit board would be an additional resistor to limit
the current at 5v to 10ma?
So from quick math it seems like this solution would waste around
2.5-3W at 240vAC all the time?
Are there any other solutions any of you could think of that would be
better than this?
For safety, I was imaging an input fuse of .1A and using maybe 3-4
zeners. They are cheap enough. If something were to go wrong the fuse
should blow first.
Thanks,
Grant