Just a question
Archiver
Posts: 46,084
Asa Daryl stated, a 2n2222 quick and dirty should work.
You mentioned the transistor solution did not work. Do you know how much
current the bulb uses if you connect it to 12volts and ground with an amp meter in
series?
Also, exactly how was the transistor connected? Each lead and resistances?
The problem could easily be the transistor you used (2n3904 or 2n2222) does
not have the current capacity to drive your lamp, so that is why I (we) need to
know how much current the lamp will use with straight 12 and ground.
An easy no brainer solution can be found at the files section of yahoogroups
basic stamps.
This solution is overkill, but very effective. I also recommend to get a
handfull of the IRL520's from www.glitchbuster.com.
Shipping is very inexpensive in the usa.....less than $2.00 and the parts
arrive quickly.
For the IRL520 solution see the link below.
http://f1.grp.yahoofs.com/v1/sOW_QJzU4IJfyD9pJP5G2ATNVk5Q-FEQxI2lWGhK3_HKaftHa
mzpKCE7eRPOMSGQp98MqFhBYjVOnbTnzwF6e7xRZZvaYSnHUg/IRL520.jpg
In the mean time, give some feedback on how much current the lamp will use.
ken
======================
Hey there everyone. I finally got my project to work. The only thing is
that the lights that were communicated (advertised) as LEDS were actually
incadescent lamps. This means that they are needing 12V to power them instead of the
5V the stamp sends out at P15-P0. I am needing to figure out how to power
them and still be able to run the program I have already written. I called
Parallax and a rep suggested a driver board, but I have no time to order this. I
have tried using both transistors and driver chips, using an outside power
supply with 12V. Both proved to not work and still not provide the lamps with
enough power/current. I was thinking maybe of using solid state relays. Does
anyone have any idea or suggestions? I appreciate anything... Thanks...
[noparse][[/noparse]Non-text portions of this message have been removed]
You mentioned the transistor solution did not work. Do you know how much
current the bulb uses if you connect it to 12volts and ground with an amp meter in
series?
Also, exactly how was the transistor connected? Each lead and resistances?
The problem could easily be the transistor you used (2n3904 or 2n2222) does
not have the current capacity to drive your lamp, so that is why I (we) need to
know how much current the lamp will use with straight 12 and ground.
An easy no brainer solution can be found at the files section of yahoogroups
basic stamps.
This solution is overkill, but very effective. I also recommend to get a
handfull of the IRL520's from www.glitchbuster.com.
Shipping is very inexpensive in the usa.....less than $2.00 and the parts
arrive quickly.
For the IRL520 solution see the link below.
http://f1.grp.yahoofs.com/v1/sOW_QJzU4IJfyD9pJP5G2ATNVk5Q-FEQxI2lWGhK3_HKaftHa
mzpKCE7eRPOMSGQp98MqFhBYjVOnbTnzwF6e7xRZZvaYSnHUg/IRL520.jpg
In the mean time, give some feedback on how much current the lamp will use.
ken
======================
Hey there everyone. I finally got my project to work. The only thing is
that the lights that were communicated (advertised) as LEDS were actually
incadescent lamps. This means that they are needing 12V to power them instead of the
5V the stamp sends out at P15-P0. I am needing to figure out how to power
them and still be able to run the program I have already written. I called
Parallax and a rep suggested a driver board, but I have no time to order this. I
have tried using both transistors and driver chips, using an outside power
supply with 12V. Both proved to not work and still not provide the lamps with
enough power/current. I was thinking maybe of using solid state relays. Does
anyone have any idea or suggestions? I appreciate anything... Thanks...
[noparse][[/noparse]Non-text portions of this message have been removed]
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[noparse][[/noparse]Non-text portions of this message have been removed]
> Hey there everyone. I finally got my project to work. The only
thing is that the lights that were communicated (advertised) as LEDS
were actually incadescent lamps. This means that they are needing
12V to power them instead of the 5V the stamp sends out at P15-P0. I
am needing to figure out how to power them and still be able to run
the program I have already written. I called Parallax and a rep
suggested a driver board, but I have no time to order this. I have
tried using both transistors and driver chips, using an outside power
supply with 12V. Both proved to not work and still not provide the
lamps with enough power/current. I was thinking maybe of using solid
state relays. Does anyone have any idea or suggestions? I
appreciate anything... Thanks...
check the power for the lamp.
put a 100 ohm resistor in series with the lamp and measure the
voltage drop across it.
Solid State relays are typically to drive AC loads, so be careful
which you might select.
A TIP120 will handle 5 amps, cost about 40 cents and is available
from Glitchbuster.
Remember the NPN transistors are between the lamp and ground.
it gets wired from 12V to the lamp, then from the lamp to the
collector of the transistor, then from the emitter to ground.
a 330 ohm transistor connecting the transistor to the Stamp.
Dave