DIY flocking - need to get to 45000volts / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

DIY flocking - need to get to 45000volts

1 2 next

Move Thread

LAN_403

McLarenboy

Tue Nov 23 2010, 09:09PM

Registered Member #3437 Joined: Tue Nov 23 2010, 08:59PM
Location: Belgium
Posts: 3

Hey Guys

I was informed to ask my question here. I've been looking for the answer for a couple of weeks now and it's turning out to be quite difficult.
I'm trying to make my own flocking unit, i'm using a negative ion generator for this with a peak value of 7000volts. The results are like the professionals.

For those of you not familiar with flocking, this is the technique:

Now my flocking unit is fine for small pieces but in order to do large pieces like dashboards and doorcards i need to get to 45000volts. This will create a very large electrostatic field. In this way i can apply the flockfibres from a relatively large distance. With my current 7000volts i get the static field only when the + and - are about one inch from each other.

The answer to boost the voltage is either:
- flyback transformer of a CRT-monitor
- cockroft-walton multiplier

In any case i'm no good at electronics and electricity. And the fact that it is dangerous makes it impossible for me to have a go.

I've found this link which offers some possibilities but which one could i use;

Can someone guide me in the right direction?

Pinky's Brain

Wed Nov 24 2010, 02:25AM

Registered Member #2901 Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837

So the only current running comes from static charge transfer of the particles? I can't imagine that's even in mA range. Together with the fact you want DC a multiplier is your best bet.

To reduce the number stages you will want to feed it from a comparatively high voltage source, but a CRT flyback based circuit is complete overkill. A xenon trigger transformer should do fine.

The "Battery Powered High Voltage Source of DC Power" power supply on that page you linked is a good example of what you need. A simple oscillator driving a high ratio tiny transformer followed by a multiplier. If you can find a circuit which keeps the sustained current below ~100 uA and the stored energy below ~100 millijoule it will be no more dangerous than a van de Graaff generator (which would probably work for this too, but is not very compact).

Or if you want something even simpler, you can use mains for the oscillation :

(<- don't use this, I'm an idiot ... read below).

EDIT : ugh I should really be more careful what I say, with 8 stages that circuit would actually have a pretty nasty amount of energy ... and you can't really reduce the capacitors in the multiplier because the low frequency would make the droop too high.

Coronafix

Wed Nov 24 2010, 04:13AM

Registered Member #160 Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938

I think t CRT transformer is your best bet.
If you pull one out of an old tv, you can get the multiplier too.
You won't get 45000v but you could possibly get 30000v.

Cool technique by the way. Been meaning to make a slot car track with a friend and have tunnels and bridges and all. Now I know how to make the grass. :)

hboy007

Wed Nov 24 2010, 07:00PM

Registered Member #1667 Joined: Sat Aug 30 2008, 09:57PM
Location:
Posts: 374

>> You won't get 45000v but you could possibly get 30000v.

HR8870 or HR80341 will output 45kV if driven correctly

(oh I forgot: this is WITHIN specs)

Pinky's Brain

Thu Nov 25 2010, 01:37AM

Registered Member #2901 Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837

I still say that is complete overkill, he is not drawing an arc or putting significant power into anything.

A tiny capacity high voltage AC source (like from a trigger transformer) followed by a multiplier should serve him fine ... and if correctly designed mostly safe to the touch too.

McLarenboy

Thu Nov 25 2010, 05:53PM

Registered Member #3437 Joined: Tue Nov 23 2010, 08:59PM
Location: Belgium
Posts: 3

so which one would you suggest of these:

And then add a cockroft-walton mutlipier you say?

radiotech

Thu Nov 25 2010, 07:31PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

Before anything will move in an electrostatic field you have to charge it first. We called it frocking, and was used to coat clutch
disks in some tape recorders.

McLarenboy

Thu Nov 25 2010, 07:50PM

Registered Member #3437 Joined: Tue Nov 23 2010, 08:59PM
Location: Belgium
Posts: 3

Ii've already covered that part Radiotech. I've succesfully flocked small pieces with the same result as professional equipment. But inorder to do large pieces i need to boost the power...

Steve Conner

Thu Nov 25 2010, 09:08PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Oh, for flock's sake.

If you're inexperienced with electronics, just make a Van de Graaff generator and stick your workpiece (flockpiece?) on top.

Antonio

Thu Nov 25 2010, 09:51PM

Registered Member #834 Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644

I would try a Wimshurst machine. More current than a Van de Graaff and simpler to connect. What is the material that is "flocked" over the substrate? I can make a test.

1 2 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob