What type of relay do I need ??

Thread Starter

Seaker

Joined Feb 3, 2013
32
This is a bit of a long story but I will try and make it quick!
I purchased a couple of 220 Volt AC outlets off of E-Bay, I thought that they had a motion sensor and light sensor included in the units. When they arrived I found that they came minus the light sensor.
I now want to make a project up incorporating an external light sensor to power the units so that they will operate only at night.
I found a schematic that looks like it will do the job (cheap and easy) however I have never built a project using a relay and am unsure of what specifications I need to consider when buying the relays?

These combined units ( light and motion sensor) will be low powered using a single 9 Amp LED light in each unit for illumination and of course are powered by 220 VAC.


Here is the schematic that I want to build:





Thank you in advance for you input.
 

thatoneguy

Joined Feb 19, 2009
6,359
Did you contact the seller to see if you can return the ones you purchased for units that did have the light sensor and PIR sensor?

If not, The circuit you have will need a separate power supply from the Light itself, a 12V, 250mA DC would suffice for the circuit above.

You'll want a relay with the coil rated as 12V, contacts rated for at least 10 Amps @ 220V, it's best to go on the high side for current, and the higher current don't cost much more when you are in the range of < 10A.

Here is a thread with different dark detector circuits for this as well.
 

Thread Starter

Seaker

Joined Feb 3, 2013
32
Thank you thatoneguy;
The error was mine in not reading the description well enough, so I have to eat the items as a failure on my part.

I intend on using a 12VDC converter with the end cut off as the power source these are cheap enough to buy.

From what you have said I need a 10amp relay with AC voltage greater than 220VAC. Is that correct?

I have available a 12 Volt DC relay with 10Amps 250 Volts AC will this work?
The item has 5 pins on it, 2 for the DC side and three for the AC side. When wiring would I connect the Positive AC line to the light and connect the negative (-) AC line to the relay ( like wiring a light switch)? What about the third pin how does this connection point get connected.

Thank you again!
 

thatoneguy

Joined Feb 19, 2009
6,359
If you have a 10A @220V relay handy, it'll work.

The relay with 5 terminals are laid out as:

2 pins for coil
1 pin for switch common
1 pin normally closed (connected to common when relay is NOT energized)
1 pin is normally open (connected to common when relay IS energized)

Normally, the hot wire is connected to the common pin, and the output is taken from the Normally Open pin of the relay. The Normally Closed contact should be insulated.

If you are planning to run the 9W LEDs from the 12V Supply that will be a bit different, your last post confused me.
 

Thread Starter

Seaker

Joined Feb 3, 2013
32
Hello Again;
Thank you very much I think I have it down now, will set it up on a bread board and check out the wiring prior to soldering up a board.
 

Thread Starter

Seaker

Joined Feb 3, 2013
32
Sorry for the confusion, the light bulbs that I will be using are spot lights rated at 9amps 220 volts AC.and will be connected into the socket assembly that I purchased off of E-Bay.
 

Thread Starter

Seaker

Joined Feb 3, 2013
32
Well I did it again, I had a mind cramp and stated that the 220 LED lights where 9 Amps, that is incorrect they are rated at 9 Watts not Amps.
Well I suppose it is true what they say that the mind is the second thing to go when one gets old!
 
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