Which resistor for anti-spark wiring circuit?

[Adrian Smith 1]

I am thinking of wiring, from a diagram I have found, an anti-spark connection which would require a resistor soldered in line with the connector on a wired loop. I am just not sure what type and capacity to get as the diagram is not too clear. It is for a 6S set up. Any help here would be gratefully received. Thanks

[Denis Watkins]

Adrian, from the web

Resistor Value

For most ESC's with around 1,000uF of total capacitance, use a 1Ω 2watt resistor when using up tp 25v (6s lipo), or 10Ω 5watt resistor when using voltages over 25v. This value will charge the capacitors slow enough to avoid the hookup spark, yet fast enough to still allow the ESC to arm properly (under half a second). The power rating is low because the only time the resistor has to dissipate the maximum power is on initial hookup. After that point, the differential voltage between the supply and the capacitor charge decreases quickly, which reduces current and therefore power dissipation.

I meant to add Adrian, the diagrams I have seen are excellent, so follow them

This is a very small amount of resistance, just to slow things down long enough to avert a spark.

Edited By Denis Watkins on 06/05/2017 12:45:57

[Adrian Smith 1]

Thanks Denis, very helpful. My only other thought that has just come to mind is when the high voltage positive lead is connected and I am ready to fly do I still leave the auxiliary anti-spark loop lead connected? It probably sounds like a dumb question but I am full of them!

[Andy48]

For electric flight you don't really need an anti spark device. All my models have an arming plug and its never been a problem.

[Denis Watkins]

Good question, in some leads, the resistor always remains built in Adrian, and it will do no arm to fly it, but if is is convenient, and not a problem, then take it out of the circuit.

Others may not have experienced the loud unnerving crack from joining up multi cells, but the arc will damage plugs. Am a fan of resistors.

[Tim Hooper]

Jeti make anti-spark connectors;

**LINK**

I use them on all my 5S+ models, on the female positive connector to the ESC. No sparks. No problems in several years of use.

Tim

[Adrian Smith 1]

That looks like a good option Tim. A bit more of a simple soldering job too.

[Frank Skilbeck]

Posted by Andy48 on 06/05/2017 13:13:21:
For electric flight you don't really need an anti spark device. All my models have an arming plug and its never been a problem.

Wthout an antispark device my 8s setups really make me jump and can't be doing the connectors (or arming plug) any good. Like Tim I use the excellent Jeti antispark connectors on 6s and above.