Author Topic: Panel Meters  (Read 1879 times)

0 Members and 1 Guest are viewing this topic.

Offline Login to see usernames

  • Hero member
  • ****
  • Posts: 980
Panel Meters
« on: March 13, 2010, 03:11:30 am »
I'm thinking of getting some panel meters to add to my set up.

Volts ... 0-150
Amps ... 0-5

Question,

It's pulsed DC, so can I used DC meters? or AC meters?
Dynodon, what kind of meters did Stan have on his Control Boxes?

Thanks

Offline Login to see usernames

  • Member
  • **
  • Posts: 235
Re: Panel Meters
« Reply #1 on: March 13, 2010, 03:43:41 am »
Don, make sure you get meters that are enough over your specs so you won't damage them.
Standard analog meters seem to work best.
I have blown 2 digital meters from BEMF, and have yet to blow a analog meter.

Offline Login to see usernames

  • Hero member
  • ****
  • Posts: 980
Re: Panel Meters
« Reply #2 on: March 13, 2010, 04:59:32 am »
Thanks for the tip.

Do you know if I need AC or DC meters for accurate measure of pulsed DC?

Offline Login to see usernames

  • Member
  • **
  • Posts: 235
Re: Panel Meters
« Reply #3 on: March 13, 2010, 06:55:41 am »
I'm measuring amperage off the alternator with DC meters.
When I pulse I use DC.
However I do notice and can measure AC voltages on the digital DMM.
The DC meters do just fine.
I use a DC meter just after a diode bridge for the rotors current. Did use a 5 ampere meter.
Also just for sake of seeing developed current on my cell, I use a DC meter on the stator.
If you pulse the rotor with a duty or delay between pulses you will get a swinging current effect, from zero to whatever you allow your load to get to.

I have fried 2 digital ammeters using my Lawton pulser, have found out its from switching the frequency change capacitors while under a load of 1 amp or more. Learned to lower the load before I switched the frequency band.   

Offline Login to see usernames

  • Hero member
  • ****
  • Posts: 980
Re: Panel Meters
« Reply #4 on: March 13, 2010, 07:05:26 am »
Interesting, I guess the capacitor discharge could overload it.
Thanks

Offline Login to see usernames

  • Member
  • **
  • Posts: 235
Re: Panel Meters
« Reply #5 on: March 13, 2010, 16:16:38 pm »
Yeh, I don't know what it is with the Lawton but apparently there's no protection for the meter as I did not install any.
I was thinking it takes a hit through the negative line BEMF of a coil when I made the switching changes.
I don't know much about protecting these things, the Lawton circuit needs some minor updated protection schemes for digital meters and internal 555 protection to take the abuse of current type experimentations.

I blasted the poor thing multiple times using high currents.
After a few times of my abuse I started adjusting the current below 1 amp before I would make a switched timing change and all has been good in the last year.

Have connected many coils and transformers of various sizes from low currents to very high currents.

You shouldn't run into any problems if you keep the current down.
Have you got your Jolt PWM up and running? 

Offline Login to see usernames

  • Hero member
  • ****
  • Posts: 980
Re: Panel Meters
« Reply #6 on: March 13, 2010, 16:59:19 pm »
No, not yet, but I did get a bunch of optocouplers of assorted kinds, I'll plan to use those to isolate my pulsing circuit from my higher power circuit.

One thing you need to run those is a huge resistor, Stan used 25 Watts, to bring down the high power connection to the mA range to send into the Opto. But I guess it's better to burn an Opto than possibly something worse on the pulsing circuit. I'll do a bit of math and may have to buy the $8 resistor when the time comes...

I'm not really doing any building or testing on this until university is over, things are just too busy now.

Offline Login to see usernames

  • Sr. member
  • ***
  • Posts: 363
Re: Panel Meters
« Reply #7 on: March 14, 2010, 17:03:27 pm »
The meters on the panels were DC.
Don