G
[email protected]
- Jan 1, 1970
- 0
I am currently working on a project to regulate the speed of a
computer's case fan using a momentary switch (see http://
groups.google.com/group/sci.electronics.design/browse_thread/thread/
7cc6e2b62e9e6cbc/).
After working with one of the other users, I was able to come up with
a workable circuit based on his reference design, located here:
http://www.usenet-replayer.com/cgi/content/viruscheck?/9/8/1/3/1171353189.59.pdf
The problem is that I cannot find the specified transistors. I was
able to aquire the rest of the components with minimal difficulty, but
the Trans. are nowhere to be found.
What I need is a short list (doesn't have to be complete, of course)
of transistors that would be equivalent to a 2N4401 NPN switching
transistor. It must take a 5-volt signal (<15mA) on the base from a
TTL IC, and use this signal to control a twelve volt current not
exceeding 250 mA (The higher this maximum, the better, but less than
0.5A Max). As can be seen from the diagram mentioned above, a low
input to the transistor disables the current, while a high (~5v)
signal enables it.
This is kind of an urgent matter as tommowow will be my last
opportunity to pick them up; after which I will have to wait in agony
until Monday-not a good experience.
Cheers.
computer's case fan using a momentary switch (see http://
groups.google.com/group/sci.electronics.design/browse_thread/thread/
7cc6e2b62e9e6cbc/).
After working with one of the other users, I was able to come up with
a workable circuit based on his reference design, located here:
http://www.usenet-replayer.com/cgi/content/viruscheck?/9/8/1/3/1171353189.59.pdf
The problem is that I cannot find the specified transistors. I was
able to aquire the rest of the components with minimal difficulty, but
the Trans. are nowhere to be found.
What I need is a short list (doesn't have to be complete, of course)
of transistors that would be equivalent to a 2N4401 NPN switching
transistor. It must take a 5-volt signal (<15mA) on the base from a
TTL IC, and use this signal to control a twelve volt current not
exceeding 250 mA (The higher this maximum, the better, but less than
0.5A Max). As can be seen from the diagram mentioned above, a low
input to the transistor disables the current, while a high (~5v)
signal enables it.
This is kind of an urgent matter as tommowow will be my last
opportunity to pick them up; after which I will have to wait in agony
until Monday-not a good experience.
Cheers.