Simple 2000V Microwave Power Supply / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

Simple 2000V Microwave Power Supply

previous 1 2 3

Move Thread

LAN_403

radiotech

Sun Dec 27 2009, 05:55PM

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

A meter for a power supply could first decide on a test current, say 0.001 A which would make the load resistor 3E5 or 300,000 Ohms.
Then a 0-1 milliamp panel meter would read full scale , 3000 volts.
The meter resistance need not be considered,A neon lamp like a NE-86 in series would not materially affect the reading. It would show the circuit to be hot as long as the capacitor had at least approx 60 volts across it. A second NE-86 across the meter terminals would serve two purposes, it would light if the meter open-circuited and also prevent an ark inside the meter. Analog meters are not spooked by coiler activities and dont need a battery to power them.
Many panel meters can be opened to allow a custom drawn, calibrated scale, to be inserted. Keeping an eye on how long the lamp glowed after power down would indicate the condition of the capacitor.

Aussienitro

Tue Jan 05 2010, 09:54AM

Registered Member #2399 Joined: Mon Sept 28 2009, 09:29AM
Location:
Posts: 27

Thankyou fellas.

I've bought three 10kV 0.1uF capacitors and three microwave diodes for the voltage multiplier, revised to 3x so I wont need a meter reading over 10kV. Also two 100v analogue meters, one for voltage out of multiplier and one for the capacitor. So I'll need to now divide the voltage by 100 at the meter and draw a couple extra zeros on the card.

Anyways since I'm only doing this to learn, experiment. What would happen if I used the smaller 1nF caps as opposed to 0.1uF for the multiplier?

Dr. Dark Current

Tue Jan 05 2010, 09:57AM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

Why you don't use the capacitors from the microwave? They are usually rated around 1uF and will safely charge to 5kV DC, most likely to 6kV without a failure. They fail internally at around 8-10kV DC.

If you used too small caps in a multiplier, the output would drop to almost nothing if you tried to put a load on it.

Renesis

Tue Jan 05 2010, 03:21PM

Registered Member #2028 Joined: Mon Mar 16 2009, 08:13PM
Location: Norway
Posts: 319

Klugesmith wrote ...

Î˜Ç»Ð¿Ä·ÃŸ for the tip. Along with Î© and Î¼, we can properly state temperatures in Â°C and RLC damping ratio as Î¶.
I'll make a little cut-and-paste reference file of commonly missing symbols.

Be shure to add that with laptops things are a bit more complex. You must hold the functions-button

fn

while pressing num lock

num lk

on my compaq this is on the same button as

scroll

This turns your keyboard completely on its head.

Then you must hold Alt while typing the Unicode on the keyboard area between M and 9. M=0, J=1, K=2, L=3, U=4, I=5, O=6. 7, 8 and 9 remains the same. Then release Alt.

255, 255, 30
30, 255, 30:

Â Â â–²
â–²Â â–²

Aussienitro

Fri Jan 15 2010, 03:32PM

Registered Member #2399 Joined: Mon Sept 28 2009, 09:29AM
Location:
Posts: 27

Hi Hazmat, thankyou for the reply. I'm tackling this issue now as the box is complete (1/2" plywood), So I'm thinking I should line the base with steel to act as the ground however if I'm reading that right, from what you have said I'll have to insulate the MOT base? and just run the second lead from the base into the multiplier (or just not line that portion under MOT).

Its changed quite a lot from plan and now includes variac as well as a low voltage outlet with dimmer, 0-300ish volt AC/DC outlet, full and half wave DC both rippled and smoothed (350v 3300ÂµF cap). And a reciever to charge and trigger capacitor remotely. Oh and it now has an onboard 3000V 100uf cap with two 12kV ross engineering relays to charge and trigger it.

I'm not sure why people are suggesting half wave rectification? Why is that safer then full wave? I wont be using a FWBR anymore rather a voltage tripler and would like to make it full wave to allow me to tap it as a laser power supply (though more of the 10kV 0.1ÂµF caps are too expensive for me to think of that just yet, only have 3). I only have 1 microwave cap and they aren't exactly cheap either.

One more question, regarding the voltage divider for the meters. The 100v meters have 100kÎ© resistance so I had to make a 9.9MÎ© resistor to divide it by 100. Now what I did was use a vero board to solder them on but now am worrying that the arc will jump between the tracks? Is this concern justified? It just looks like it will go ZAP and be destroyed when placed between the 3000v 100ÂµF cap. I used 17 1/2W resistors in all, 9 1MÎ© ones and smaller ones to make up the difference.

Aussienitro

Mon Jan 18 2010, 08:02PM

Registered Member #2399 Joined: Mon Sept 28 2009, 09:29AM
Location:
Posts: 27

Wondering if anone knows a good online switch supplier? I'm finding it incredibly frustrating to find a 3 position ON-ON-ON rotary switch, it seems so incredibly common place but there seems to be a big void regarding them. Needs to handle 240v @ ~8-10amp. Plenty of ON-OFF-ON but no ON-ON-ON. Really infuriating, cost is no issue.

It was to switch between AC/DC/HV in this supply.

previous 1 2 3

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