Eliminate Huge Spark when Connect ESC to battery

[Super-Hornet]

For those who has R/C that required high voltage and current, do u always having "uncomfortable" feeling each time u plug in the battery and it give u a big spark and loud "Piak!" sound? Do that too often and u notice your battery connectors starting to wear out from spark (like spot welding).

I know there is a commercial version of a device to remove the big spark but I was thinking maybe we can actually develop something like that easily using the following items:

MOSFET => IRFZ44 (which is 50A, 60V)
( 2 MOSFET in parallel in order to increase the current to 100A)
A capacitor
A Resistor

What I thinking is that, the MOSFET is connect in series between ESC connector (dean, bullet) and ESC power input (in other word, separate ESC to the dean/bullet connector)
Then a high resistance resistor is in series with a capacitor. The +ve side of the capacitor is connected to the "Gate" of the MOSFET. The resistor and capacitor is connected to the dean/bullet connector.

With that, when u plug in the connector to the battery, the capacitor will slowly charge up to the voltage of the battery. It is slowly charge up due to high resistance. Once the capacitor reaches certain voltage, the MOSFET is turn ON and your ESC will have full power from battery.

I haven't test this out yet. Maybe it will work

I see whether I can test it out and let u all know the result.

SH

[edmond22]

For those who has R/C that required high voltage and current, do u always having "uncomfortable" feeling each time u plug in the battery and it give u a big spark and loud "Piak!" sound? Do that too often and u notice your battery connectors starting to wear out from spark (like spot welding).

I know there is a commercial version of a device to remove the big spark but I was thinking maybe we can actually develop something like that easily using the following items:

MOSFET => IRFZ44 (which is 50A, 60V)
( 2 MOSFET in parallel in order to increase the current to 100A)
A capacitor
A Resistor

What I thinking is that, the MOSFET is connect in series between ESC connector (dean, bullet) and ESC power input (in other word, separate ESC to the dean/bullet connector)
Then a high resistance resistor is in series with a capacitor. The +ve side of the capacitor is connected to the "Gate" of the MOSFET. The resistor and capacitor is connected to the dean/bullet connector.

With that, when u plug in the connector to the battery, the capacitor will slowly charge up to the voltage of the battery. It is slowly charge up due to high resistance. Once the capacitor reaches certain voltage, the MOSFET is turn ON and your ESC will have full power from battery.

I haven't test this out yet. Maybe it will work

I see whether I can test it out and let u all know the result.

SH

Hey Bro,

A few of us flying heli did that for the 6s with great success. However, ever since I moved to 12s setup, I have not gotten very far and I kept destroying the resistors that I gave up doing that keke. Maybe the resistor rating is not good enough I do not know.

Will be keen to see what works for you. I am quite used to the piak sound, I am accustomed to just commit and connect without hesitation, that seems to take the edge off the piak. However I am all ears to see how it works for you, I know it is wearing out my connectors lol.

[LittleGiant]

For those who has R/C that required high voltage and current, do u always having "uncomfortable" feeling each time u plug in the battery and it give u a big spark and loud "Piak!" sound? Do that too often and u notice your battery connectors starting to wear out from spark (like spot welding).

I know there is a commercial version of a device to remove the big spark but I was thinking maybe we can actually develop something like that easily using the following items:

MOSFET => IRFZ44 (which is 50A, 60V)
( 2 MOSFET in parallel in order to increase the current to 100A)
A capacitor
A Resistor

What I thinking is that, the MOSFET is connect in series between ESC connector (dean, bullet) and ESC power input (in other word, separate ESC to the dean/bullet connector)
Then a high resistance resistor is in series with a capacitor. The +ve side of the capacitor is connected to the "Gate" of the MOSFET. The resistor and capacitor is connected to the dean/bullet connector.

With that, when u plug in the connector to the battery, the capacitor will slowly charge up to the voltage of the battery. It is slowly charge up due to high resistance. Once the capacitor reaches certain voltage, the MOSFET is turn ON and your ESC will have full power from battery.

I haven't test this out yet. Maybe it will work

I see whether I can test it out and let u all know the result.

SH

It will work. There are similar mods on this RC (resistor capacitor) mod.

[Adrianli]

Can these MOSFET really hold up to the demands of constant high voltage and high current???

Especially in a high moisture content environment in a high powered electric boat, u will be looking at 10-14S lipo and 200-300A current draws.

[Super-Hornet]

I going to come out a prototype and test it out. Will report back once the prototype is done.

I might decided to use a microcontroller to "Delay" the MOSFET to turn on after 1 or 2 seconds instead of charging up capacitor. The reason, I will explain later.

SH

[Ghostfit]

Subscribed ! ...I'm one of those who really cannot stand the 'mini explosion' everytime I connect a HV setup.

Even my 4s lipo setup has the resister Cap charging mod ! ...would be eagerly watching your Spark Elimination Xperimatation (---?)

[LittleGiant]

http://www.ace-cars.info/DE%20AC/download/Anleitung%20um%20Funken%20bei%20hohen%20Spg.%20zu%20vermeiden.pdf

Ok this is the article i read before. ACtually no capacitor or mosfet is needed.

[Super-Hornet]

Using a resistor to charge up our ESC capacitor method I too aware off..but I was thinking of different approach.

See har, using resistor to charge up our ESC capacitor has the following:
Adv
----
-> Easy to build.
-> Lowest component count.

Disadv
-------
->If your battery is in higher cell count, the resistor u required will be like 1W or maybe 3W (anything smaller wattage and u might burn the resistor instead...especially during our ESC give us the initializing tone using motor)
->Two steps is required (See below)

For the 2 steps method...(that is, 1st plug in resistor plug and then main power for ESC), sometime u forgotten to connect the resistor plug 1st and therefore, it give u the "Piak" sound.
Then sometime u forgotten about the small resistor connector that, when u unplug main connector, u assume all is done but actually there is a power connected to your ESC. U risk over discharging your main battery.
It also required you to modify every battery pack u have for that resistor connector (unless u create an adaptor that separate your battery and your ESC).


What I thinking of doing is a single connector to battery instead. Plug in the battery just like normal method but the circuitry will not power up (or stop sudden charge up our ESC capacitor) our ESC till like 1 or 2 seconds later. By that time, the connection is already connected.

SH

[LittleGiant]

Using a resistor to charge up our ESC capacitor method I too aware off..but I was thinking of different approach.

See har, using resistor to charge up our ESC capacitor has the following:
Adv
----
-> Easy to build.
-> Lowest component count.

Disadv
-------
->If your battery is in higher cell count, the resistor u required will be like 1W or maybe 3W (anything smaller wattage and u might burn the resistor instead...especially during our ESC give us the initializing tone using motor)
->Two steps is required (See below)

For the 2 steps method...(that is, 1st plug in resistor plug and then main power for ESC), sometime u forgotten to connect the resistor plug 1st and therefore, it give u the "Piak" sound.
Then sometime u forgotten about the small resistor connector that, when u unplug main connector, u assume all is done but actually there is a power connected to your ESC. U risk over discharging your main battery.
It also required you to connect every battery pack u have for that resistor connector (unless u create an adaptor that separate your battery and your ESC).


What I thinking of doing is a single connector to battery instead. Plug in the battery just like normal method but the circuitry will not power up (or stop sudden charge up our ESC capacitor) our ESC till like 1 or 2 seconds later. By that time, the connection is already connected.

SH

Why not just create a plug with an auxillary connector that is connected to a high wattage resistor?

Escs only initialise when the minimum input voltage is reached (voltage level of esc capacitors) so in the case of having an Aux connector, by the time the esc initialises, there should be enough stored energy in the esc caps for the audible tones. The problem with the resistor is that capacitors function like a closed swtich when completely discharged so the resistor will be subjected to high amp loads initially upon connection. But this current surge will only last for a split second (depending on the capacitance). I think the common 1/8 W resistors should be able to take it. Even if without the resistors, the aux switch is only an aux switch. Just let it wear out from the sparks to prevent damage to the main connector because performance will not be affected since it is not the main connector that gets worn out.

Maybe escs in the future will have built in spark preventor? Something like 1 second delay from connecting the battery before the esc main capacitors are connected to the power source through a mosfet with the gate connected to a RC circuit?

[Adrianli]

See my thread : http://www.daddyhobby.com/forum/show...ighlight=spark

[Adrianli]

If you buy Schulze ESC, such circuit already included inside. Maybe u can ask them abt it. But I doubt they will tell u lah.

[Super-Hornet]

With that kind of size and complicated ESC, there is definitely some circuitry to control the "Piak" sound.

This is what I intend to create...that is, one connector to battery only (no misc plug for resistor )

Oh.. I need to change to P-Junction MOSFET liau. The IRFZ44 is N-Junction. The reason is due to the common ground our ESC and RX and Servo is sharing. Unless our ESC power and RX+Servo uses different power source (in other word, ESC uses one battery and RX,Servos,Gyros uses another battery).

SH

[Adrianli]

No need that huge one lah. Their smaller ones also have this circuit as long as its for HV and the latest version.

See : http://www.schulze-elektronik-gmbh.de/index_uk.htm

Maybe u might wana buy one and reverse engineering. But the smallest is priced at Euro299. The huge one is Euro799.

[Super-Hornet]

Let me try the MOSFET method 1st. If can work, then no need to reverse engineer them. If cannot work, then see how.

SH

[Ghostfit]

I see what SH is getting at ! ...the battery and ESC connectors goes together directly without the need to pre-connect lots of wires in sequences.

A mosfet/circuit provides the resistance to prevent a surge of current (Piak) and moments later, all resistance is removed.

There's beauty in this system, you connect the battery as you would a LV system without fear of the 'PIAK' flying into your eyes !!!