I'm having a problem with turning on a 12v 50w halogen lamp. I've tried using a relay which failed and also a IRF 520 MOSFET transistor which also failed. I'm not sure what's the problem. I tried it with a 12v 1.5w LED lamp and the thing worked. This is the schematic that I used as an example
I just changed the input voltage to 12v dc from a power supply. So, can anybody point me where I might have done wrong.
As an additional information, the transistor is able to feed 6.5 - 9.2 A, so in theory that should be more than enough to drive the halogen lamp right?
The problem is the mosfet you are using is not a 'logic level' mosfet. Standard mosfets require +10vdc gate/source voltage to fully turn on, while 'logic level' mosfets will fully turn on with a arduino +5vdc output pin voltage.
Here is an example of a logic level mosfet:
hi lefty, thaks a lot again for the hint. I ordered a similar N-MOSFET type transistor, not here yet, so I'll update it later.
Now, I'm having a similar issue. I tried to power a track lighting similar to this
I use a 12VDC 5W lamp for it. Now, I can turn on the light by plugging it straight to a 12V power supply. However, when I plug the lamp to the track lighting, I couldn't turn it on, even when I power the lighting straight to the power supply. There's no specification written in the box, but there's a sticker on it saying 12V 50W.
Question is, is it okay to plug a 12V 5W lamp to a 12V 50W lighting system? Do I need to use the same transistor use to power 12 V 50W lamp as in your reply before?
Sorry if it seems stupid, never dealt with this sort of lighting situation before
lunchboxav:
hi lefty, thaks a lot again for the hint. I ordered a similar N-MOSFET type transistor, not here yet, so I'll update it later.
Now, I'm having a similar issue. I tried to power a track lighting similar to this
I use a 12VDC 5W lamp for it. Now, I can turn on the light by plugging it straight to a 12V power supply. However, when I plug the lamp to the track lighting, I couldn't turn it on, even when I power the lighting straight to the power supply. There's no specification written in the box, but there's a sticker on it saying 12V 50W.
Question is, is it okay to plug a 12V 5W lamp to a 12V 50W lighting system? Do I need to use the same transistor use to power 12 V 50W lamp as in your reply before?
Sorry if it seems stupid, never dealt with this sort of lighting situation before
Sorry but I don't know a thing about the:
to a 12V 50W lighting system?
It would appear that there is nothing wrong with your lamp or seperate 12 volt power supply, but maybe your
'to a 12V 50W lighting system' can't handle the additional load of adding the lamp to it? Again I just don't have enough information about your system to help with your symptom.
Sorry about the language, what I mean is the relay works, it clicks, but it's not enough to turn on the light. I think, maybe because I didn't feed enough external power to the lamp, but I've left that for a while now and am now focusing on using transistor. But thanks for the link, I think I need to do more reading while being away from the circuits.
It would appear that there is nothing wrong with your lamp or seperate 12 volt power supply, but maybe your
'to a 12V 50W lighting system' can't handle the additional load of adding the lamp to it? Again I just don't have enough information about your system to help with your symptom.
Lefty
apologize lefty. by saying 12V 50W lighting system what I meant was that rail lighting thing on the picture. I tried to gather information about this thing, it's just none. but I'm sure there's something about it, because without installing the lamp to the rail lighting, I can turn on the light. I'll see if I can get more information about this thing
Hi retrolefty, I had the same issue again. I used the FQP30N06L transistor, it's the same stocked by Sparkfun as you mentioned, but I still couldn't turn on that 12V 50W halogen lamp. Can't figure out what's the issue here. Any clues or hint? Anybody? Thought this was gonna be easy.
lunchboxav:
Hi retrolefty, I had the same issue again. I used the FQP30N06L transistor, it's the same stocked by Sparkfun as you mentioned, but I still couldn't turn on that 12V 50W halogen lamp. Can't figure out what's the issue here. Any clues or hint? Anybody? Thought this was gonna be easy.
Cheers.
Well the first thing I would look at is what is the voltage of the lamp supply at when you attempt to turn it on? Could be whatever the higher voltage source your using can't handle the current load of the lamp when you turn on the mosfet and it's causing the voltage to turn off or 'fold back' to prevent damage to the voltage source. Also be sure you have a common ground connection from the voltage source wired to both the source lead of the mosfet and to a arduino ground pin.
One thing to bear in mind is that when you power on an incandescent lamp, it take a large current surge while the filament heats up. For a standard bulb it is around 10 to 14 times higher than the normal operating current. For a halogen lamp it is even higher. If you measure the resistance of the lamp when cold and divide that value into 12, that will tell you how large the current surge is.
A 12V 50W halogen lamp runs at just over 4A, so I think the mosfet needs to be rated for at least 100A peak current (although your 12V power supply will have some internal resistance too, so you might get away with less).
okay, I use a 12v dc power supply, wired according to this picture:
So it has that shared ground connection. Well, the power supply can feed max 1A. I tried turning on a 12V 5W lamp and it worked. So, could it be that the transistor just didn't give enough current to turn on the lamp?
oh forgot to tell, I measured that there's 12V voltage supplied to the halogen lamp. this is the output of the circuit, not just the one supplied straight from the power supply
If there is 12V across the lamp but it is not lighting up, then the lamp has failed. Alternatively, you only think there is 12V across the lamp, and you have a bad connection.
Are you really using a breadboard to make the connections? A breadboard is not capable of carrying 4A, let alone the much higher current that flows when you turn on the lamp. You need to use good soldered connections or screw terminals to carry that amount of current.
One reason why the 5w halogen may not work in the track light is some tracks that are low voltage use somewhat of a hybrid transformer/switching supply and have a minimum draw and will not operate unless that minimum is fulfilled but that all depends on the supply
winner10920:
One reason why the 5w halogen may not work in the track light is some tracks that are low voltage use somewhat of a hybrid transformer/switching supply and have a minimum draw and will not operate unless that minimum is fulfilled but that all depends on the supply
yeah, I suspect the same thing too. but then I went barebone and connect the 50w halogen straight to the circuit and Arduino, didn't work. I don't think I fed enough current to make it 50w. Pretty sure I have 12V though.
So, say, will it work if I use 16V or 24V power supply?
