detecting 110VAC -PETER MAY
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Posts: 46,084
Peter Mays idea of a coil wound aroud one of the conductors is not bad for
an 'Aussie sparky'
However one must be aware that this is essentially a current transformer
which capable of inducing a lethal potential if excessive windings are used
You only need five volts or less for sensory purposes
My advice would be to start with as few as ten windings, measure the
potential with a multimeter then add or subtract windings as required to
achieve the 5 volts
This 5 volts will need to rectified (2 diodes, half wave should be fine) as
the AC mains will induce both a positive and negative voltage
Once you have rectified the 5 volts have this inturn feed an optocouples led
The output of the opto in then connected to stamp
ie led on = output high
The opto isolates the stamp from the 110 ac to prevent damage. This will
also 'blow' in the event of a mains surge as the voltage induce will rise
obove 5 volts list burning the optos led out
Far cheaper than replacing you stamp
Hope this helps
Pete,
Check out http.www.execpc.com/~teba/
You can have your Chevy, I'll take a turbine thanks
Cheers
Wayne
ps. small world eh
Original Message
From: Peter May <manager@s...>
To: <basicstamps@egroups.com>
Sent: Monday, October 23, 2000 8:56 AM
Subject: RE: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
> Well he is a change. Something I can add a thought on. You could wind a
coil
> yourself and place around one of the conductors only, Either the active or
> neutral (I am a sparky here in Oz and that's what we call them anyway).
> Depending on the number of turns and if a former is used etc will cause a
> voltage to appear at the coil ends. It's rough but if it serves to work
then
> perhaps a commercial version could be bought.
>
> Hope this helps....
>
>
Original Message
> From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9qyN1-JZEh1XHYun-_kYVcNAfFWt68OVysJ8r8_ZcTSO9YeWUNBH4Cox-OnP6MTfvxN8SDni0-vZXmNcRqE]rjmca@u...[/url
> Sent: Monday, 23 October 2000 7:00
> To: basicstamps@egroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
> BS2
>
>
>
Original Message
> From: Freddie Leaf <freddie_leaf@y...>
> To: <basicstamps@egroups.com>
> Sent: Sunday, October 22, 2000 2:38 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
BS2
>
>
> > The pump is triggered by a float. The pump and float are submerged down
> > in the sump-pump pit. The only thing I have access to is the 110VAC
pump
> > power cord going into the pit. I also have access to the pipe
containing
> > the water being pumped out of the pit. I guess I could get a flow meter
> > but that sound expensive.
>
> *****************
> It does not sound practical to tap into the pump wiring...it is usually
all
> sealed on a submersible pump. Consider a current sense transformer that
> could be installed on an extension line cord. Digikey lists a unit on
page
> 593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
> resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
> (220 mv/amp with 120 ohm). The output could be rectified and conditioned
> for Stamp use.
>
> Ray McArthur
>
>
>
>
>
>
>
>
>
>
>
an 'Aussie sparky'
However one must be aware that this is essentially a current transformer
which capable of inducing a lethal potential if excessive windings are used
You only need five volts or less for sensory purposes
My advice would be to start with as few as ten windings, measure the
potential with a multimeter then add or subtract windings as required to
achieve the 5 volts
This 5 volts will need to rectified (2 diodes, half wave should be fine) as
the AC mains will induce both a positive and negative voltage
Once you have rectified the 5 volts have this inturn feed an optocouples led
The output of the opto in then connected to stamp
ie led on = output high
The opto isolates the stamp from the 110 ac to prevent damage. This will
also 'blow' in the event of a mains surge as the voltage induce will rise
obove 5 volts list burning the optos led out
Far cheaper than replacing you stamp
Hope this helps
Pete,
Check out http.www.execpc.com/~teba/
You can have your Chevy, I'll take a turbine thanks
Cheers
Wayne
ps. small world eh
Original Message
From: Peter May <manager@s...>
To: <basicstamps@egroups.com>
Sent: Monday, October 23, 2000 8:56 AM
Subject: RE: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with BS2
> Well he is a change. Something I can add a thought on. You could wind a
coil
> yourself and place around one of the conductors only, Either the active or
> neutral (I am a sparky here in Oz and that's what we call them anyway).
> Depending on the number of turns and if a former is used etc will cause a
> voltage to appear at the coil ends. It's rough but if it serves to work
then
> perhaps a commercial version could be bought.
>
> Hope this helps....
>
>
Original Message
> From: Ray McArthur [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=9qyN1-JZEh1XHYun-_kYVcNAfFWt68OVysJ8r8_ZcTSO9YeWUNBH4Cox-OnP6MTfvxN8SDni0-vZXmNcRqE]rjmca@u...[/url
> Sent: Monday, 23 October 2000 7:00
> To: basicstamps@egroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
> BS2
>
>
>
Original Message
> From: Freddie Leaf <freddie_leaf@y...>
> To: <basicstamps@egroups.com>
> Sent: Sunday, October 22, 2000 2:38 PM
> Subject: Re: [noparse][[/noparse]basicstamps] Detecting if 110VAC device is on or off with
BS2
>
>
> > The pump is triggered by a float. The pump and float are submerged down
> > in the sump-pump pit. The only thing I have access to is the 110VAC
pump
> > power cord going into the pit. I also have access to the pipe
containing
> > the water being pumped out of the pit. I guess I could get a flow meter
> > but that sound expensive.
>
> *****************
> It does not sound practical to tap into the pump wiring...it is usually
all
> sealed on a submersible pump. Consider a current sense transformer that
> could be installed on an extension line cord. Digikey lists a unit on
page
> 593 of their catalog, #237-1103-ND, $2.89 ea. With a 60 ohm terminating
> resistor, it outputs 110 mv/amp, whch would double for a 120 ohm resistor,
> (220 mv/amp with 120 ohm). The output could be rectified and conditioned
> for Stamp use.
>
> Ray McArthur
>
>
>
>
>
>
>
>
>
>
>