Need help with a small project.

[Ronald]

I'm trying to use a transistor as a switch. Catch is I am using a
premade device that has a flashing led that blinks as it operates. I
want to use the source of the flashing led to trigger a transisor to
drive a 6 volt 555 lamp. I need a refresher... my mind can't remember
back when I did this stuff in college. anyone have any solutions I'd
appricate it.

 

[William Sommerwerck]

This is electronics 101. Trivial electronics 101.

You pick a transistor with a sufficiently high collector-current capability
to drive the lamp. The lamp goes from B+ to the collector. Pump enough
current into the transistor's base, the transistor saturates, bringing the
collector voltage close to zero, and the lamp goes on.

Note that the input current to the transistor, multiplied by the DC current
gain of the transistor, has to be at least the current the lamp requires for
full output.

 

[Dave Plowman (News)]

In article
<7a58d098-f995-481b-98b0-947aa6b98148@e7g2000yqf.googlegroups.com>,
Ronald <rcoonjr@buckeye-express.com> wrote:

I'm trying to use a transistor as a switch. Catch is I am using a
premade device that has a flashing led that blinks as it operates. I
want to use the source of the flashing led to trigger a transisor to
drive a 6 volt 555 lamp. I need a refresher... my mind can't remember
back when I did this stuff in college. anyone have any solutions I'd
appricate it.

Depends on what makes the LED flash. Some LEDs have the flashing
electronics built in so have a continuous DC supply. If it's a plain LED
and all you can access is the intermittent signal to that, use a second
transistor to charge a cap and use your main switching transistor fed from
that cap.

--
*Born free - taxed to death *

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.