Peter, don't arc it for 30 seconds.

All you need to see is one arc to know it works.  You just bring the ground up to the positive and as soon as it arcs, take the ground away and you are done.  You then know that it is working.

Actually I sort of

Actually I sort of miss-spoke. I didn't hold it on for 30 seconds straight, just on and off very briefly for a total of about 30 seconds.  As a matter of fact, I wasn't making it arc when it blew.  Any idea why I got no arcing with the wall warts?

Peter

Wall warts

Peter,

There are two different types of wall warts: 1.) The more modern solid state devices that don't handle shorts well; and 2.) The "old" transformer types that use wound wire that can handle brief shorts (no, not the underpants!).

Rick

Wall Warts

First, 300 mA should have been lots to power the ION module.

I have been in contact with the manager at Oatley previously, and he backs up what Patty says, very few of these modules are defective.  Really they are too simple to be bad all that often, IMO.

The 12 volt supply is most likely what cooked the module.

The wall wart should be a regulated DC supply rated at, (IIRC) no more than 9 volts @200 mA, for the Oatley 9V module.  The best way to test if in doubt is to connect a 9 volt battery as the supply.

Arcing is one way of testing for output but making the unit arc repeatedly is not really good for it.  Another way would be to make a foil leaf electroscope like I did for the video that went with the article.

Sorry for the delay in response I just got back online (on a borrowed laptop) after losing video on my own laptop recently.

Oatley Ion Generator

Kevin,

Thanks for your input. I did read your follow-up article about the new 9 volt generator, however, mine has a tag on it that says:

Oatley Electronics

IONB2

I/P DC 12V

red + black -

I assumed this was the older 12 volt model (that's what it says) What I cannot understand is why it did not work with either a 9 volt 300mA wart or a 12 volt 1000mA wart but did function temporarily with a 12 volt power pack.  That is what led me to believe it might have been bad.  When I get my replacement can I use the Radio Shack 1000mA wart set at 9 volts? Based on what Oatley has on their website, wouldn't the "grassinator" work better with 12 volts for long O scale grass? 

from Oatley____________________________________

Althought IONB2 has a nominal voltage of 12V it can produce useful EHT voltages when powered from a lower supply voltage: 6KV from a 4.5V/10mA supply,  around 12KVKV from a 9V/20mA supply, around 15KV KV from a 12V/25mA supply,

_________________________________

IYHO do you think the voltage or the amperage did the damage?  I will certainly not be testing it by arcing it.

Thanks,

Peter

older model

Hi Peter,

I'm hoping we at the MRH forums can help you get your grass applicator working.  I`m not an EE so please excuse my rudimentary knowledge.

I was mistaken in thinking that you had the newer 9 volt module, sorry.

Using 12 volts for the module you had should have been fine.  If it had been the newer 9 volt module you were working with, I would say it was the higher than rated voltage that made it smoke, however perhaps that was not the case since you did have the 12 volt module.

It's hard to guess why the first two adapters you tried did not appear to work.  Assuming the connections were solid and they were both functioning DC power supplies, I can think of no reason for them not to have worked with the module.

As for using the wall wart set to 9 volts, I think that should work.  The applicator does not need the 1000mA provided but if I understand correctly it will only draw the current it requires for operation, from the supply.  If your replacement module is the 9 volt Oatley module, don`t try to use 12 volts with it.

One thing about the 12 volt power pack you used that fried the first module.  If it is not a regulated pack it could have been supplying much more than 12 volts to the module.  I know Terry Roberts or Charlie could explain this better than I can.  It's to do with the current load being high enough to regulate the pack to the 12 volts.  If unregulated, that 12 volt 5 Amp supply could apply as much as 18 volts or more to a circuit that is drawing a fraction of the rated current output from the supply.

I`m modeling HO myself, but I have applied some of the longest grass I have been able to find, 6mm with my applicators.  Even the very marginally powered fly swatter applicators can apply the 6 mm grass effectively.  That said, the higher power versions do work better in my opinion.

I`ll try to get back regularly to see if you have solved your issue or not.  Still working on borrowed laptops here!

Older-Newer Model?

The picture in the Oatley website shows the same tag on it as I have here and is marked IONB2 which according to them IS the newer model (the older model being IONB1), but they say it can handle the higher power.  Perhaps there is a "newer" new model??  Yikes!!  Anyway, I saw no difference in the height of 6 mm or 2 mm grass so I'm pretty sure it was not "grassinating"!! As a matter of fact grass shaken out with the unit unplugged was just as high.

When I get the replacement I will let you know what the tag says on it.  Just to be clear, I regulated the voltage of the power pack to 11.8 volts on my meter before I hooked it up. 

I read these forums pretty regularly and I've never seen anyone have a problem. 

Looking forward to getting the replacement. 

Thanks again for your help.

Peter

Grassinator Working Just Fine

I obviously got a bad generator as the replacement the kind folks at MTV sent me works perfectly, first shot.  My 6 mm grass now stands tall-ready for the 1/4 scale mower!!  Thanks to everyone for their suggestions and to MTV for sending a replacement at no cost.

Peter

Great news Peter!

Great news Peter!

A happy ending

Even received compliments from the "better half"!!

It really does an outstanding job simulating long grass-thanks Joe and Kevin for your efforts to develop an affordable alternative, ya gotta love that!!

Peter

The Moral of this thread

Always buy your shorts at Wal-Warts

Credit Where Credit Is Due

What Hair?

Kevin----you've given me a great idea for increasing my hair thickness!  The "Hairinator"!  Any idea how to attach the grounding spike painlessly???

Your modesty is refreshing-you da man!

Peter

Hairinator

No pain, no gain!

The Hairinator

Laughing...

Peter, thank-you for making both my wife and myself laugh this morning!

hmm. maybe some of those sticky contact things they use for EEG's and ECG's?

I'd like to see pictures of the results!  I've got a spot to fill in too.

My new Grassinator Problem is...................

.................where to get 9/12 volt negative ion generators.  I was showing mine to some members of a club and offered to make one for our own Pennsy GG1 but I don't see them offered here anymore.  Any ideas?

Thanks,

Peter

Oatley Electronics Pty. Ltd.

Here  you go, In Australia

http://secure.oatleyelectronics.com//advanced_search_result.php?keywords=negative+ion+generator&osCsid=2anhqg7ntnhsbm2v1i1fnpq7a0&x=16&y=6

Oatley Electronics Pty. Ltd.

email: graeme@oatleyelectronics.com
Website: http://www.oatleyelectronics.com/