HobbyKing SS series 18A ESC.

As I bought the ESC’s for my TriCopter I was thinking that no matter what,
it should be able to drive the DT750 good enough, with or without updated firmware.
With this in mind, I bought the HobbyKing SS 18A ESC.

HobbyKing SS 18A








If you look closely the sticker indicating battery and output ports a reversed 😉

This was probably a good idea, they’re cheap, can be programmed with a Turnigy program card,
and when I received the ESC’s, I was that they were fitted with the ATmega48 MCU.
This is nice, as I own a USBasp, so the new firmware for those can easily be programmed to those.
BUT: Some of these boards have their nRESET pin disconnected through the fuse bits.
I haven’t tested it though, as I still need some of the parts, to build the entire copter and then testing the settings
by the programming card.

Instead let’s look at the FETs onboard these things:

P/N FETs of HK SS 18A








The SO-8 chips are soldered on in pairs, not very nice work, but the solderblobs between the pins are okay, as they’re connected to the same spot on the PCB.
The P-FETs are Si4425, -30V -11.4A@Vgs= -10V.
The N-FETs are Si4856,  30V 17A@Vgs= 10V.

One thing I noticed was the one of the boards was fitted with the A1730 P-FETs.
These are -30V -6.5A@Vgs= -10V.
Those FETs will probably do fine, but I really don’t like the idea of just replacing one part with any other.

The FETs are chilled with a layer heat-transporting goo of some sort, it’s black, and sticks a bit to the FETs.
On top of this is a aluminum plate, just pressed on to this:

FET Chiller









The topside, confirming the ATmega48 chip, as well as the programming pins:

HK SS 18A ATmega48









Left side to right:
7805 – 5V voltage regulators, SO-8 on top is another 5V regulator,
a bunch of resistors, some transistors and of course the ATmega48.
The programming pins on the right is like this from the top:
nRESET – Pulled up to Vcc by 4k7 resistor.
VCC – +5V
GND – 0V
SCK – Clock for SPI interface
MISO – Input for SPI data
MOSI – Output for SPI data

I don’t now what my idea with this post was, other than inform you about the product from HobbyKing.

I’m not responsable for any damage to you or your equipment.