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What is new at Herkules II ?

After plenty of successfull testflights and measurements with the HERKULES I, i went back and invested again numerous hours and worries. Now i want to present the result.

What is new? What has changed since HERKULES I?

Functions in a brief:

* PCB-Board became smaller (only 60x60mm).
* better, smaller MOSFETs with less RDSon (3mOhm).
* Central current measurement was removed.
* Bulky WAAGO-Power connctors replaced by solder pads. Soldering of 3.5mm gold contact connectors now possible.
* Only one 8-pin Micromatch connector leaving including programming, I2C, PPM, UART and powersupply for FlightControl.
* Simple programming and softare update by bootloader.
* New Firmware: Setting I2C-adresses, active freewheeling, timing etc. by simple USB-programming cable!!
* Multiplex, XT60 or 3.5mm gold connectors could by directly soldered on the board for battery power supply
* No blind- and burried vias any more, therfore cheaper manufacturing of PCB possible.
* Now switching regulator with 7.5V/2A as pre-regulator for internal 5V or external flight control included.
* Full 6S (26V) powersupply voltage possible (due to switching-regulator).

More precisely:

1) Design / Weight

* Even smaller: quadratic-handy shape of only [b]60x60mm[/b].
* Minor [b]Weight[/b] of only [b]28g[/b] (35g with high current connector).
* Total weight saving compared to single ESC solution of 180g at Quadro- and 360g at Octocopter because the heavy and mess wiring harness can easily be replaced.
* Flexible mounting. Drill-hole distance fitting to Mikrokopter, CADMICOPTER etc.
* Minimal build-up time due to all signal lines (I2C, PPM; UART, Power Supply)  to FlightControl are inclued in one Micromatch connector.
* Big WAGO motor connectors removed.
* The motors phases could now be connected either on top or on bot via big solder pads or soldered 3.5mm gold contact connectors.
* The programming connector for all controllers is integratd in the Micromatch connector. Therefore no additional solderpads are necessary any more => saves also space!
* The PCB layout was optimized t reduce impedance of the power-rail and became even low-ohmic. So power dissipation on PCB is also reduced.
* The whole powerboard could be mounted on a flat cooling plate because all components on the bot have same height.

2) Operation / Reliability

* One machine-made PCB. No hookup wire. No High Power distributor. No defective contacts. And everything again "Made in Germany"
* Even more powerfull and robust by using low-ohmit N-chanel MOSFETs (Imax up tu 100A according datasheet!)
* Proper, fast MOSFET pre-drivers for clean and saturated controlling of the N-channel MOSFETs. Drivers are build discretely.
* 4-layer high-current PCB with 110um copper.
* Central curreent sense and battery reverse circuitry removed to save PCB-space.
* Optimize switching of MOSFETs avoids parasitic opening and shoot-througs.

3) Flexibilty

* Stone-prooven ATMEGA8 or ATMEGA168 with mature BLDC firmware.
* Firmware-Updates by simple bootloader and USB connector possible.
* Selectively UART, PPM or I2C on Micromatch connector.
* Simple Micromatch-Connecctor with all signals. Only one ribbon cable between Herkules and FlightControl needed.
* One blue LED for each channel signaling motor and BLDC status.

4) High-Power

* Exclusevly N-channel MOSFETs in high- and lowside with propper pre-drivers.
* Only one type of MOSFETs for all positions due to bootstrap driver on highside => cheaper, more powerfull than P-channel.
* Extended power supply range from 2-6S (6-26V)!
* Power up to 10Arms/40Apeak per motor (40Arms/160Apeak for quad-board) without any cooling when using activer freewheeling. With very good cooling up to 20Arms per motor possible.
* Optimized motor start-up strategy, tested with a numerous amount of different motors.

5) The new firmware

We invested lots of time in developing and optimizing our own BLDC-firmware and can now offer new features.

* Three different control variants, PPM, UART, I2C available.
* The I2C- and UART adresses are programmable by USB programming too. No solder jumper at all needed!
* Motor commutation timing programmable between 0 and 30 degree for differnt motors.
* For extra powerfull motors or missing cooling posibility (e.g. mounting in a closed case) powerloss can be reduced by almost 70% by activating activer freewheeling.
* Start-up strategy optimized and tested with lots of motors.
* Safe detection of wrong commutations avoids blocking or burning of motor.

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