# Negative charge circuit to repel snow paticles

Discussion in 'Electronic Basics' started by Rajkumar512, Nov 24, 2003.

1. ### Rajkumar512Guest

Is there any one who can advice me on building a negative charge circuit. I am
a beginner at circuit designing and i want to confirm my ideas to build a
Negative Charge Circuit.

I am planning to use a 555 timer to generate 1kHz clock frequency and use a
operational amplifier LM741 to bring it down to below 0 Volt. I am using a long
copper wire connected to op-amp output for negative charge. I am also aware
there are other passive component needed, but i can work that out by myself.

The idea of long copper wire which will be place in zig-zag position on top of
wooden/plastic tray, is basically to test whether it has the potential to repel
snow paticles which is said to be negatively charge by many enviormental
research.

My Question:
Is positive voltage inverted to negative by an Op-Amp considered as negative
charge?

Thank you.
Raj

2. ### Don BruderGuest

Negative is negative, I'd say. Whether that means a connection to the
"-" post of a battery, the "-" leg of a rectifier's output, or the
inverted output from an op-amp being fed a postive input, it's still
below 0 volts, which is, last I knew, pretty much the wroking definition
of negative.

3. ### GarethGuest

That sounds like an interesting experiment, but the electrostatic force
is very weak and I would be surprised if you were able to produce a
noticeable effect without very high voltages. Do you have any
information about how much negative charge there is on a snow particle?
You could then get an idea of how much force will be exerted on it and
how much negative charge you would need to see a significant effect.

I don't understand why you need an op-amp and a clock - if you want a
negative charge why not just connect the negative side of your power
supply (which I assume is a battery?) to your zig-zag copper wire, and
connect the positive side to earth?

You may be able to get a more significant negative charge by using
static electricity. For example you could rub a balloon on your hair,
it will then become charged (I can't remember if it gets positive or
negative charge), you could then see if it attracts or repels snow
particles. A problem here is that the balloon will not stay charged for
very long. Perhaps a better way would be to support your zig-zag copper
wire on some very good insulators, you could then charge the balloon and
use it to charge the wire and repeat this charging process regularly.
This would be like a very crude Van de Graaff generator.

Have a look at:

http://science.howstuffworks.com/vdg.htm
--

4. ### Rajkumar512Guest

I don't understand why you need an op-amp and a clock - if you want a
The reason for using clock is to introduce pulse, it's just and idea i got it
based on my past experiment with magnetics. It's like this, say a fixed and
constant force of North Pole magnet is pushing another North Pole magnet, the
distance is fixed at same point. But when i used a non-constant force at fixed
North Pole magnet (like swinging) the other North Pole reachec greater distance
of point. I hope you understand what i mean.

The Op-Amp is to invert the positive clock to negative, (this is the point
where i am not certain, and the reason for posting the message at this news
group) I think by inverting below zero volt, may introduce negetive charge. My
little knowledge say that zero is ground point, so more than zero is positive
thus it's positively charge, if below zero it may be negatively charge. I am

By the way, below are the some of internet resources that confirm me snow
particles do carry negative charges and a site that says a scientist already
did this experiment before i originally though of it.