This forum is for specialized infomation important to the construction and safe operation of the high voltage electrical supplies and related circuitry needed for fusor operation.
At some point I would like to be able to measure the primary current or beam current if floating the HV output in my old Labtrol power supply. Been trying to figure this out on my own so far. Correct me if I'm all off the mark.
One of the 2 blue wires in the second pic is the input to the inner primary windings- which of the 2 blue wires depends on which polarity is selected. If I just hook a clamp meter around the correct blue wire, I can read the amperage directly. Maybe even tear apart the clamp meter, and relocate the readout somewhere convenient.
Am I anywhere close to reality or completely off my rocker?
If your experiment needs statistics, you ought to have done a better experiment.
Sure, why not. In fact, since the primary winding has two ends, you have two wires to choose from. Just don't put the clamp around both at the same time.
For a permanent monitor, it's not hard to set up a current transformer that will work fine in the zero to 10 or 20 amp range, and give you a proportional voltage that you can measure with a panel meter or your true-RMS DVM.
Thanks for the info Rich. 60 Hz transformers are not my forte. No electrical engineer here. So...
Wondering if there is a relatively uncomplicated way to hook up a digital panel meter on my low voltage side on the above unit. I have studied the FAQ on wiring for real fusion fusor Part 2. It does show what I would consider simple wiring for a digital panel meter, but for the high voltage side.
If your experiment needs statistics, you ought to have done a better experiment.
As Rich has pretty much already posted above, there are countless options out there for metering exactly what you're trying to do. Look on any surplus website such as MPJA and you will find several ready made digital panel meters with current transformers already included. Simply thread the needle and go.
You might also find a direct meter that plugs into the wall at the local hardware store, with a pass through. the advantage is that you can measure the ac amps of individual components or the system in total- for pump, diffusion pump, primary transformer, current, etc. As with the meter abpve, the one I found displays 1/10th amp increments. The handheld ac amp meters and several panel amp meters I have used were accurate to only ~ an amp increment.
Dan Tibbets wrote:You might also find a direct meter that plugs into the wall at the local hardware store, with a pass through. the advantage is that you can measure the ac amps of individual components or the system in total- for pump, diffusion pump, primary transformer, current, etc. As with the meter abpve, the one I found displays 1/10th amp increments. The handheld ac amp meters and several panel amp meters I have used were accurate to only ~ an amp increment.
Dan Tibbets
I have heard of those a long time ago, but would never have thought of it now. I'll be good with the panel meter for now- but I'll keep those plug-ins in mind for down the road. Thanks.
If your experiment needs statistics, you ought to have done a better experiment.
Got my meter- no instructions. Don't want to take any chances so I'm posting before and after photos of the wiring. This is the right way to do it- right?
If your experiment needs statistics, you ought to have done a better experiment.
Looks OK, though I've never used one like that myself.
If you first wire it into an extension cord or power strip,
then you can test it with an assortment of familiar loads,
without the inconvenience of very high voltage on secondary winding.
When trying it on a variac-controlled circuit,
remember the panel meter wants at least 80 volts AC to power itself (according to the catalog page).
All models are wrong; some models are useful. -- George Box
Just tested it a bit- there was no response from the meter at all. Only went up a few hundred V on the HV- it's not hooked up to the chamber right now. Looks like you're right about hitting that minimum 80 V for it to work at all. I may just do as you suggested and hook up the meter at the outlet to the HV and measure the entire input instead of just the beam current.
If your experiment needs statistics, you ought to have done a better experiment.
I looked thru all the panel meters at mpja. Didn't see anything else that would be helpful. Do you know of anything offhand that are powered separately?
If your experiment needs statistics, you ought to have done a better experiment.
