siliXcon SX Controller
siliXcon SXtl02 24kxa0840-840
siliXcon has made impressive improvements to its website since I last investigated it in 2022. The changes made finding detailed information about the new SX controller easy.
The controller is rated for up to 18kW. It allows a maximum input voltage of 80VDC and has a 400A measurement range.
The SX controller weighs 150 grams more than the SC controller used in earlier EM models. The SX is physically much more like controllers from other manufacturers. Instead of the SC's flying leads, the SX has threaded power terminals and a single signal connection port.
The switching frequency is specified as 20 kHz.
The SX controller is part number EL01S-50301-00-00. It has a US retail price of $1854.73.
Controller Part Number, Decoded
The controller is marked “24kxa0840-840.” This part number breaks down as follows:
24 = 24 transistors (I assume a 3-phase, 6-switch H-bridge, with each switch comprising 4 paralleled MOSFETs)
k = LM5008 supply (95V, 350mA, DC/DC Buck Switching Regulator)
x = USB, isolated CAN Bus, isolated 5V UART, GPIO
a = Analog sensor input (Sin-Cos), Hall sensors compatible, single-ended digital sensor compatible (SSI)
08 = 80 Volt maximum
40 = 400 Amp measurement range
-840 = internal fuse connected, internal CAN bus terminator
siliXcon SX Pinout
Credit: siliXcon
Control signals interface via a 34-pin Superseal 1.0 connector. The pinout is identified in the adjacent table.
siliXcon states the following features:
5 General inputs
2 Non-isolated digital inputs
1 Output low-side switch with PWM
1 Motor temperature sensor input
1 Motor position sensor input
Power terminals (Battery positive & negative, Motor phases A, B, C) are via M6 threaded inserts.
Behind the small hex-shaped cover resides a USB-C connector for programming and a pair of configuration jumpers.
Controller Heatsink
Controller Heatsink
The adjacent photos show a new heatsink used in conjunction with the siliXcon SX controller. The DC-DC lighting converter is also mounted on this heatsink. Although not as large as the heatsink used on the Dragonfly, it is larger than the previous EM heatsink.
Frankly, I'm a bit surprised anything more than the ePure's heatsink is required. In monitoring my 2021 Race's heatsink temperature, I've never seen it get above 10° C more than ambient - despite abusing it in Red mode. But then, I don't ride in the desert or like Gael Chatango.
Perhaps the controller gets hot internally and reduces current thereby hurting performance under certain grueling conditions?
Perhaps the heatsink is needed for features like anti-rollback?
The increased motor RPM does cause more frequent switching of the power MOSFETs, thereby increasing switching losses and generating more heat.
I guess EM would not have added the weight and the expense if it was not necessary.
As a side note, you can also see the battery connector in the upper left corner of the photo.