Quote:
Originally Posted by Finnster
That is basically what I did with mine. However I did not want to use a Deans miniplug as it leaves the possibility of the little prong on the mini connector making contact w/ the main Deans plug. ==> Dead short.
If it was wired carefully to make that impossible then I would feel ok about it. I just don't want any lipo fires in my travel bag I'm carrying my RC stuff around in. Instead I just prefer this:
You can use a smaller resistor, but then you have to get a higher watt rated resistor, and those get big and bulky. I used a 1/2W resistor (as its small and easy to find at ratshack) and an appropriate ohm value. I prolly should get a 1W resistor, but I just have it plugged in a few secs so its fine (its a 2200 IIRC.) Really you just need to take the initial "sting" out of it, and it always takes me a couple of seconds to plug in one, then grab the Deans and plug that in. Spark is tamed by then. Here's a handy calculator
BTW Brian, shouldn't it read [P=V^2/R ]? |
True, a totally insulated and polarized mini-connector would be best. The diagram with the mini-Deans was just for demonstration purposes.
Like you said, you don't really need to keep the charging resistor circuit engaged the full amount of time. All you really need is 2/5th the total charge time (which is 86.5%) to take the "sting" out.
And yes, power
is V^2 / R, but I always like to add in a little extra heat capacity for safety (factor of 2). But since the duty cycle is so low, you could probably easily get away with V^2 / R
* 0.5. I tend to over-engineer.
