AC powered OR gate??

[Alex C]

Hi,

I have a load, which is a lamp of 240V and 50W, I need 2 sensor to drive it.
Both sensors are 240V powered and output is 240V.
How do I create an OR gate for this AC driven device so that if any one of
the sensor is triggered, the lamp will light up? I can't join both output
together as it will blown by the back fire if one output is high (240V) and
the other is OFF.

Appreciate if you could send your suggestion to e_mc2@pacific.net.sg as I
seldom have access to newsgroup..thanks

 

[Jim Thompson]

On Mon, 1 Nov 2004 23:54:31 +0800, "Alex C"
<e_mc2@pacific.net.sg.nospam> wrote:

another question, do I need to put a rectifier across the terminal as in DC
operated relays to absorb the high current dischage when the relay is switch
off?


[snip]

You need to tell us more about your "sensor".

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[Tim Wescott]

Alex C wrote:

pardon me for my ignorant... there is 240V powered solenoid relay in
electronics shop? oh... all along I've using only up to 24V solenoid
relays...

ok, will try the suggested method

thanks Jim!

"Jim Thompson" <thegreatone@example.com> wrote in message
news:d8lco0pbn4ph3abpjqj37pig82iq8uqalj@4ax.com...

-snip-

That depends on what shop you frequent. There are 240V AC relays
available from industrial suppliers. In the US I'd look at Granger or
possibly McMaster-Carr.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Joerg]

Hi Alex,

another question, do I need to put a rectifier across the terminal as in DC
operated relays to absorb the high current dischage when the relay is switch
off?


If everything you use including the relays is made for 240V AC then you

don't need any rectifiers. 240V AC relays should be easily found at a
larger electrician's supply house. At Digikey you can mail order 240V AC
relays.

Regards, Joerg

http://www.analogconsultants.com

 

[Alex C]

I'm not sure what if the state of the output from the sensor when it's
"OFF"...it could be floating.

"Tam/WB2TT" <t-tammaru@c0mca$t.net> wrote in message
news:ArmdndArFtkV6RvcRVn-uQ@comcast.com...

"Alex C" <e_mc2@pacific.net.sg.nospam> wrote in message
news:418653e5$1@news.starhub.net.sg...
Hi,

I have a load, which is a lamp of 240V and 50W, I need 2 sensor to drive
it.
Both sensors are 240V powered and output is 240V.
How do I create an OR gate for this AC driven device so that if any one
of
the sensor is triggered, the lamp will light up? I can't join both
output
together as it will blown by the back fire if one output is high (240V)
and
the other is OFF.

What does OFF mean? Is it an open circuit, or is it switched to the other
side of the line?

Tam

Appreciate if you could send your suggestion to e_mc2@pacific.net.sg as
I
seldom have access to newsgroup..thanks

 

[Alex C]

pardon me for my ignorant... there is 240V powered solenoid relay in
electronics shop? oh... all along I've using only up to 24V solenoid
relays...

ok, will try the suggested method

thanks Jim!

"Jim Thompson" <thegreatone@example.com> wrote in message
news:d8lco0pbn4ph3abpjqj37pig82iq8uqalj@4ax.com...

On Mon, 1 Nov 2004 23:35:13 +0800, "Alex C"
e_mc2@pacific.net.sg.nospam> wrote:

Hi,

I have a load, which is a lamp of 240V and 50W, I need 2 sensor to drive
it.
Both sensors are 240V powered and output is 240V.
How do I create an OR gate for this AC driven device so that if any one
of
the sensor is triggered, the lamp will light up? I can't join both output
together as it will blown by the back fire if one output is high (240V)
and
the other is OFF.

Appreciate if you could send your suggestion to e_mc2@pacific.net.sg as I
seldom have access to newsgroup..thanks


Use a relay on each "sensor" output... parallel the poles to get the
"OR" function.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.