Static Grass Applicator Update – by Kevin Rowbotham
How to use the new-andimproved high output 12V negative ion generator from Oatley electronics to build your own static grass appplicator ...
I have tested the module to 9 volts, and it worked well, and produced a whopping 12KV on the charge wire. With the low DC input voltage and minimal current requirements, using alkaline or rechargeable battery power is now easier than ever if you’d like to make your static applicator truly portable.
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n the Mar/Apr 2010 issue of Model Railroad Hobbyist magazine, I presented three different methods for building a static grass applicator. Two of the the examples used negative ion generators from Oatley Electronics in Australia – a 12V version and a 120V version.
It’s good to see Oatley has this new, better negative ion generator because the 12V generator is the preferred model over the 120V version.
Oatley has since discontinued the 12V version of the generator I used in the article and replaced it with a newer model. In this update, I discuss how to wire the applicator using the new model, since the wiring has changed.
Figure 1: Kevin’s original article in the Mar/Apr 2010 issue of MRH demonstrated step-by-step 3 different ways to build your own static grass applicator. One of the best ways was using the 12V negative ion generator from Oatley Electronics. Unfortunately, Oatley has discontinued the generator shown in the article, so here author Kevin Rowbotham gives updates on how to use the new improved 12V negative ion generator from Oatley.
Because the new ion generator has a lower input voltage, between 6 and 9 volts DC, changes should be made to the optional power indicator LED portion of the circuit to allow for that.
appropriate for mounting in the chassis, making sure to determine and record the specification of the LED.
Begin by determining your power supply voltage from either a battery or AC adapter. Select an LED that is
You can use the handy LED resistor calculator at, http://led.linear1. org/1led.wiz to determine the resistor value you need.
Page 67 • Issue 11-09• Sep 2011 • Static Grass Applicator Update, page 1
The new ion generator can produce nearly three times the 5KV output of the former module. Powered at only 6 volts DC, the new generator puts out an impressive 8KV, while only drawing around 30mA of current. Supplying the module with 7.5 volts DC ramps the output up to over 10KV.
While it’s possible to build a completely safe static grass applicator with Oatley’s 120V negative ion generator, it does take more care in order to make sure the final applicator wiring is safe. With the 12V model, there’s almost no wiring mistake you can make that will result in an unsafe applicator. Worst case, you may get a hair-raising static jolt, but nothing much worse than touching a door knob on a cold winter day after you’ve been dragging your feet across a rug. On the next page, I show a wiring diagram for the new 12V negative ion generators. The major change involves the green wire in some
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