14 Jan
2006
14 Jan
'06
9:02 a.m.
On 1/15/2006 at 8:59 AM Dave Brown wrote:
SNIP
For a practical implementation of this sort of
arrangement see the
circuit here-
http://homepages.ihug.co.nz/~tractorb/collins/Collins%2075S%20mains%20switc
h%20.pdf
Very nice job, particularly using the grounded/earthed neutral as the
return. Here in the USA, one side of the 120vac is tied to the third prong
of the mains receptacle in the distribution panel, so this would also be a
way to avoid tying into an incorrectly-wired receptacle (more common than
you'd think!).
Cheers,
Chuck
Chuck is correct, this is major reason for using standby transformers
(AC or SMPS) to provide low current power for power controlling the
main power.
To other one who did this modifcation on a radio equipment and very
low current control of the SSR relay, find a cheap LED small digital
alarm clock, uses 1" cube transformer and is wired. Majority of
these are not on the PCB board and ready to use, cut a small area of
PCB to get diode(s), cap for DC output where transformer wires are
soldered on. Usually 100mA, 16 to 12VAC. Add a fuse for the mains
side of transformer and another fuse after it.
Cheers, Wizard