By: Tillmann (IP: 83.121.0.*)
Written on: 01-01-2005 19:52
Hi,
a voltage regulator differs from a power MOSFET. You need an n-Channel MOSFET. It will not work without one, as you have noticed.
bye,
Tillmann |
By: scifi3018 (IP: 204.116.2.*)
Written on: 01-01-2005 20:34
Really? they looked the same, and in the guide i guess i was confused by the "any part will work if it is 12v and enough amps" ill try radio shack again, thanks for the guide |
By: scifi3018 (IP: 204.116.2.*)
Written on: 01-01-2005 20:35
BTW: what exactly is a mosfet, and what is it supposed to do? |
By: Tillmann (IP: 83.121.5.*)
Written on: 02-01-2005 00:38
Hi,
the _looks_ of an electronic component don't have much to say :-).
Also, the guide states "The MOSFET can be just about any N-channel Power MOSFET, as long as it can handle the 12V voltage and the amperes the fan requires."
A MOSFET is a Metal Oxide Semiconductor Field Effect Transistor. How it works and what it does is way beyond the scope of this site (even with a good background knowledge of semiconductor physics, it takes quite a while to completely understand the theory behind MOSFETs. For those really interested, I recommend the book "Microelectronic Circuit Design" by Richard C. Jaeger).
A quick and incomplete explanation: a MOSFET is a component frequently used in amplifier circuits.
bye,
Tillmann |
By: Tillmann (IP: 83.121.5.*)
Written on: 02-01-2005 00:42
PS:
Here is a good link about MOSFETs:
http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/first11/part7/page1.html
The first sentence there already explains very well what the MOSFET does in our temperature control circuit:
"The Field Effect Transistor is a device which enables us to use one electrical signal to control another."
bye,
Tillmann |
By: scifi3018 (IP: 204.116.2.*)
Written on: 02-01-2005 01:42
Thats fascinating stuff. I went to the shack today, and got the right component, and fixed up the circuit, and it works, except for my crappy soldering, it is all great, and right now the glue is setting, whe ni get a camera, i will upload some pics, and post links. |
By: cubadew (IP: 129.93.197.*)
Written on: 03-02-2005 02:27
this site really has a great assortment of knowledge... love all the tips.
I was wondering if it was possible to build a 5v version of the temp controller. I rebuilt my laptops cooling system, and all the fans run off 5v. I could use another voltage regulator, but I am really hesitant to add any more heat producing devices if I dont have to.
Im in the US, so radio shack will be hearing from me soon...
thanks for the tips |
By: UFANS (IP: 68.100.48.*)
Written on: 20-02-2005 20:39
Hi all. Quick question. My 12v power source doesn't have a ground, so what do I do?
I also don't understand the absence of the Negative lead from the 12v power source... shouldn't the negative power source run through something and then connect to the fan's negative lead? Or, does the transistor actually ground out the entire circuit's electricy? That doesn't make sense to me because I would expect a GFCI to trip or something.
Thanks !!!
UFANS |
By: Tillmann (IP: 83.121.1.*)
Written on: 20-02-2005 21:26
Hi,
two replies at once :-)
To cubadew:
You can use the circuit with no modifications for 5V.
To UFANS:
If the leads of your power source are marked as positive/negative instead of positive/ground, consider the negative lead as ground. Once you do that, then yes indeed, the "negative power source run through something and then connect to the fan's negative lead", as you wrote.
bye,
Tillmann |
By: UFANS (IP: 68.100.48.*)
Written on: 21-02-2005 00:10
Tillman,
Thanks. I am up and running. Great project.
UFANS |