I want to blink a 60w 12V bulb. I connected the circuit as shown in the picture. I get an output voltage of 12v on the multimeter, but the light bulb won't glow. I uploaded a simple blink sketch and I get a correct output at the pin with an LED.
I'm a newbie and i'm sure i've made some mistake in the circuit or its about the MOFSET.
simplr:
as shown in the picture.
Which you seem to have inadvertently forgotten to attach 
yup. edited. Sorry 
It's a Fritzing, hidden in the link.
It doesn't really show how it's connected but to OPs credit for a change component numbers are given.
simplr:
I want to blink a 60w 12V bulb. I connected the circuit as shown in the picture.
Is that even a logic level MOSFET?
What power supply you really use?
Can you please post an actual circuit diagram? This one is so unreadable it's not even possible to wire it up based on the image!
wvmarle:
Is that even a logic level MOSFET?
Datasheet only gives a 10V RDS(on) so probably not.
I don't know.
I use a UPS battery for the 12v power supply. The bulb glows fine if i connect it directly to the battery
I read the data sheet - the graphs are for Vgs starting at 4.5V, but no graph for Rds vs. Vgs.
It's an IRF type, not an IRL. That's what mostly triggered my question. The IRL types work with Arduino, some IRF seem to work as well. This one, not so sure.
But that's easy to try. Just connect connect the MOSFET in the circuit, connect the gate to +5V, see what happens.
BTW there's no pull-down resistor in the drawing, never a good idea to risk a MOSFET gate floating (when the Arduino is off or so), nor a protection resistor between Arduino and the gate. Also no flyback diode but that shouldn't be necessary in case of lights, even though it won't ever hurt. I've taken up the habit of adding those diodes, just in case.
Welease_Woggah:
Datasheet only gives a 10V RDS(on) so probably not.
So its the MOSFET? Any idea on what mosfet i should use for this? I don't wish to use a relay though
Another question: you use an old-fashioned space heater aka incandescent bulb? I assumed LED. Doesn't really change things, though they're easier to dim.
simplr:
So its the MOSFET? Any idea on what mosfet i should use for this? I don't wish to use a relay though
Have you actually tried the MOSFET the way I suggested? That'll tell you if it works or not.
I've used the IRL540 to great success with 5V gate level (didn't work with a Vgs of 3.3V, though). They can handle the current you need just fine.
wvmarle:
I read the data sheet - the graphs are for Vgs starting at 4.5V, but no graph for Rds vs. Vgs.It's an IRF type, not an IRL. That's what mostly triggered my question. The IRL types work with Arduino, some IRF seem to work as well. This one, not so sure.
But that's easy to try. Just connect connect the MOSFET in the circuit, connect the gate to +5V, see what happens.
BTW there's no pull-down resistor in the drawing, never a good idea to risk a MOSFET gate floating (when the Arduino is off or so), nor a protection resistor between Arduino and the gate. Also no flyback diode but that shouldn't be necessary in case of lights, even though it won't ever hurt. I've taken up the habit of adding those diodes, just in case.
Ok, maybe i'll just learn more about basic electronics for now and get back to the project again. Cuz I have no idea on where to connect the pull-down resistor.
BTW, any suggestions on what MOSFET i should use?
wvmarle:
Have you actually tried the MOSFET the way I suggested? That'll tell you if it works or not.I've used the IRL540 to great success with 5V gate level (didn't work with a Vgs of 3.3V, though). They can handle the current you need just fine.
I'll try and get back
Here's how to use a mosfet, although it shows a motor- no flyback diode needed in your case.
Hi,
When you do give us a circuit diagram can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Please not a fritzy picture you supplied earlier.
A hand drawn circuit can give more information.
Thanks.. Tom.. 
simplr:
Ok, maybe i'll just learn more about basic electronics for now and get back to the project again. Cuz I have no idea on where to connect the pull-down resistor.
BTW, any suggestions on what MOSFET i should use?
wvmarle:
Have you actually tried the MOSFET the way I suggested? That'll tell you if it works or not.I've used the IRL540 to great success with 5V gate level (didn't work with a Vgs of 3.3V, though). They can handle the current you need just fine.
I tried IRL540, but it still won't work. Can it be cuz I'm not using any resistors in the circuit?
No idea, can't see your circuit diagram.
simplr:
I tried IRL540, but it still won't work. Can it be cuz I'm not using any resistors in the circuit?
No, the resistors mentioned are to stop the FET overloading the Arduino output on rapid switching and to stop the bulb coming on during the boot up period of the Arduino.
TomGeorge:
Hi,When you do give us a circuit diagram can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?
Please not a fritzy picture you supplied earlier.
A hand drawn circuit can give more information.
Thanks.. Tom..
Sorry... I thought reading the frizting drawing would be easier. I'm a newbie and it is easier on frizting for me. Sorry, i'll post circuit drawings in future.
Sorry, but someone please send me a correct circuit drawing to make this project. Pleaseeee
simplr:
Sorry... I thought reading the frizting drawing would be easier. I'm a newbie and it is easier on frizting for me.
You may THINK it's easier - when all it does is tell you which wire goes where, instead of giving a good overview of an electrical circuit. For circuits that include a handful of LEDs and a single MOSFET that may be enough, but it doesn't give you an understanding of what the circuit does (and your questioning shows just that).
So just hand draw a circuit if you don't have any circuit drawing software (such as KiCAD or EagleCAD - both of which are free software) and fair chance you can find out what you're doing wrong there and then.
There are also heaps of circuit examples on MOSFET switches a quick Google search away.