Hard drive activity with 12V neon

[Chris Fonville]

I have a neon light (12V) that I would like to blink with hard drive
activity. I know I can't power it from the the HDD activity connectors on
the motherboard, so how can I accomplish what I am wanting to do? Would I
need to use a relay or transistor or something else? Should I be able to
pick it up at my local Radioshack? Thanks in advance,
Chris

 

[CBFalconer]

I have a neon light (12V) that I would like to blink with hard
drive activity. I know I can't power it from the the HDD
activity connectors on the motherboard, so how can I accomplish
what I am wanting to do? Would I need to use a relay or
transistor or something else? Should I be able to pick it up
at my local Radioshack? Thanks in advance,

Abandon the idea of using a neon. It will require something like
50 to 80 volts to strike, and about 2/3 of striking voltage to
sustain. This also means series current limiting. LEDs are much
better suited in that environment.

 

[Chris Fonville]

Well I know neon is used in computer applications all the time, I guess more
commonly cold cathode tubes, but alot of times accessories that were
designed for auto use (with the 12V cigarette lighter) can be cut and wired
using the computer power supply's peripheral molex connectors (yellow wire
for 12V). I'm pretty sure I just need to use a relay but I didn't see any
of what I needed (12VDC through the coil when I need about 3.3V, I think,
coming from the HDD activity header) at Radioshack. Any other tips?
Thanks,
Chris

 

[beav AT wn DoT com DoT au]

I have a neon light (12V) that I would like to blink with hard drive
activity. I know I can't power it from the the HDD activity connectors on
the motherboard, so how can I accomplish what I am wanting to do? Would I
need to use a relay or transistor or something else? Should I be able to
pick it up at my local Radioshack? Thanks in advance,
Chris

Basically you have a problem where you need a lot of power to start a
neon, and also a comparatively long time to do so. As the normal HDD
led blinks on and off furiously, it would rarely have the time to light
up. I would suggest that you use a couple of 555 timers to create a
psudo random on-off signal that can be tuned to stay on a little longer
most of the time.

--
-Luke-
If cars had advanced at the same rate as Micr0$oft technology, they'd be
flying by now.
But who wants a car that crashes 8 times a day?
Registered Linux User #345134

 

[Chris Fonville]

Actually these are neon speaker rings, used to go around subwoofers and they
have a setting to blink with the music and can actually cut off and on quite
quickly, I would hope enough to look good. But thank you for suggesting the
timers, I will keep that option open, too. Does anyone know if I would be
better off with a relay, transistor, or something completely different?
Thanks,
Chris

 

[kony]

Well I know neon is used in computer applications all the time, I guess more
commonly cold cathode tubes,

No, neon and cold cathode fluorescents are not synonyms, they are two
different tubes.

...but alot of times accessories that were
designed for auto use (with the 12V cigarette lighter) can be cut and wired
using the computer power supply's peripheral molex connectors (yellow wire
for 12V). I'm pretty sure I just need to use a relay but I didn't see any
of what I needed (12VDC through the coil when I need about 3.3V, I think,
coming from the HDD activity header) at Radioshack. Any other tips?
Thanks,
Chris

A mechanical relay would be relatively slow, subject to wear, and such
lights aren't well suited to being turned on and off so frequently. It
may cause premature aging->death of the invertor and they won't even light
up so instantaneously as IDE activity can occur... It may flash, but not
as well as might be expected. Bottom line is that they aren't really
suited to what you want to do, while LEDs are.

If you want to try it anyway, use a solid-state relay instead of
mechanical. You might also find the effect is better if you alternated
between dimly lit and bright, full power, rather than completely off/on.

 

[beav AT wn DoT com DoT au]

Chris Fonville top-posted (and beav fixed):

Actually these are neon speaker rings, used to go around subwoofers and they
have a setting to blink with the music and can actually cut off and on quite
quickly, I would hope enough to look good. But thank you for suggesting the
timers, I will keep that option open, too. Does anyone know if I would be
better off with a relay, transistor, or something completely different?
Thanks,
Chris

And therein is another problem - I believe (and I may be wrong) that the
neons pulse (not turn on and off) to the beat. Power is always
supplied, and a sensor of some kind detects the beat and switches the
neon between high and low power. In this case, you therefore have to
isolate the audio trigger components and figure out how to manipulate them.

On the relay/transistor question. They both can switch power on and off
- the relay is on and off only, and the transistor is close enough to
infinitly variable.

The problem here is:

1) Relays need more power to operate than transistors (they are
mechanical) and the output on the mobo for the LED may or may not be
enough. Relays are also slower than transistors.
2) Transistors are variable, so unless you get the right transistor
voltage (the same as the output on the board), you won't get the full
amount of input power out of it.

--
-Luke-
If cars had advanced at the same rate as Micr0$oft technology, they'd be
flying by now.
But who wants a car that crashes 8 times a day?
Registered Linux User #345134

 

[Chris Fonville]

Chris Fonville top-posted (and beav fixed):

And therein is another problem - I believe (and I may be wrong) that the
neons pulse (not turn on and off) to the beat. Power is always
supplied, and a sensor of some kind detects the beat and switches the
neon between high and low power. In this case, you therefore have to
isolate the audio trigger components and figure out how to manipulate

them.

The neons do not pulse, they are either completely on or completely off,
just depending on whether the audio sensor is "hearing" something at the
time. They did not fade even.

On the relay/transistor question. They both can switch power on and off
- the relay is on and off only, and the transistor is close enough to
infinitly variable.

The problem here is:

1) Relays need more power to operate than transistors (they are
mechanical) and the output on the mobo for the LED may or may not be
enough. Relays are also slower than transistors.
2) Transistors are variable, so unless you get the right transistor
voltage (the same as the output on the board), you won't get the full
amount of input power out of it.

That's what I was looking for, I am getting the feedback that the mechanical
relay will not last long, that I should go either a transistor, solid-state
relay, or optoisolator. I need to know the voltage coming off the
motherboard HDD activity headers and then find a switch that will work with
that. Thanks,
Chris

 

[Michael Culley]

If these things go on and off with an audio signal then just feed the LED voltage into where the audio signal used to go. An audio
signal may be a lower voltage than an led (2 volts audio and up to 5v for an led) so you may need to use a resistor. You can't just
run a resistor to the audio input because if it has a very high impedance the resistor will do nothing. Instead you should run 2
large value resistors across the led contacts in series and take one input off the negative of the led and the other off the centre
of the 2 resistors. Vary the values of the resistors to get the correct voltage.

Paste this into notepad:

LED FROM MOBO

-ve +ve
| |
|-^^^---^^^-|
| |
| |
| |

To audio input