1    Introduction

1.1    Key Features

• 3-phase Sensorless brushless DC motor controller
• Control Mode based on block commutation
• Supply Voltage 9-26V (3-6S Lipo)
• 30A continuous / 60A peak motor current
• High efficiency, low-resistance powerstage (total path resistance < 3mOhm)
• Active freewheeling enabling active braking using energy recuperation
• Setpoint command by I2C and PPM
• Setpoint update rate up to  450Hz
• PWM switching frequency 8kHz-16kHz
• Programmable commutation timing 24°, 18°, 12°
• Ultrafast setpoint reaction time
• Up to 200,000 field turns per minute
• Stable and wide-band firmware
• Overload protection (overcurrent, overtemp, stall)
• Telemetry capable (e.g. Graupner HoTT, Jeti Duplex, Futaba S-BUS, standard serial and others)
• Ready to fly – fully assembled
• Compact and light weight (8-fold ESC 100x100mm at < 250g)
• 100% designed and made in Germany

1.2    HERKULES III Variants

The Herkules boards are available in different variants and mounting options.
For details see product description section.

1.3    Important Safety Notice

To avoid unexpected motor starts please read the operating instructions very carefully. Improper wiring of the motor, battery or control wires, or set point or command line failures may result in unexpected startup or runaway conditions.
The user must always assume that such startups can happen and the user must ensure that his system is safe in all conditions. Please do all wiring and configuration work very carefully.  Follow all safety procedures in the manual and work exactly as described. Never program or run tests with a flight battery connected. Use a current-limited power supply to check the basic system behavior!
The Herkules III Powerboard is delivered pre-mounted and pre-soldered with battery power wires. Never try to de-solder the power-wires from the PCBs. The high thermal conductance of the power board makes special soldering equipment necessary. Standard soldering equipment will likely destroy the electronics. Soldering is only allowed on the motor connection pads and the battery end of the flight pack power wires.

Please consider also to the absolute max ratings described in the Electrical Characteristics on page 11.
 
1) DO NOT CONNECT BATTERIES to THE BOARDs before having checked them for correct operation on a current-limited power supply!  Never connect a battery without being sure that the installation has no short circuit. Always test the electronics for the first time, or after any programming or setup changes, on a current limited power supply (Vmax = 24V, Imax = 3A)
 
2) NEVER perform the first tests WITH PROPELLERS INSTALLED ON THE MOTORS! REMOVE the propellers for safety.
 
3) NEVER REMOVE ALL SCREWS at the SAME TIME !!! If you want to replace them, remove carefully ONE of the screws and immediately replace it with the new one!
=> There is a precision fit cooling interface plate between the PCB and cooling plate and if it is not arranged perfectly, you may create a short circuit in the electronics!
Removing of cooling plate will result in Loss of Warranty!

4) Don’t use metal screws to mount the HERKULES III Cooling plate on your frame. If using the holes on the cooling plate, use plastic screws. I case of hard landing (or crash) the frame is not damaging the HERKULES III ESC because the screws are breaking first. Only in case of mounting the inner screws (Mikrokopter dimensions) use metal screws, but be very careful not to misalign the boards!

5) NEVER Try to re-solder or remove the thick battery cables from the middle of the PCBs. You will not manage it because the thermal impedance of the total system is very high and you need special equipment to be able to heat up the boards without destroying the electronics.
 
6) Only solder on the END of the wires, NEVER solder on the PCBs directly. The only permitted exception are the MOTOR wires. If they are not soldered by the factory, you can solder them but be very careful and check with magnifying glasses to make sure there are no a solder balls or wire fragments on the PCB after soldering.
 
7) Don’t use any protective paint or lacquer for protecting the electronics! The electronics may be destroyed by these materials. The warranty shall be voided by the use of such coatings.
    
Please be aware that you are operating a 250A power system which demands complete respect and care during handling, setup and operation.

2    Dimension and Mechanics

2.1    Cooling Plate XL : 150x150mm

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2.2    Cooling Plate L : 100x100m

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3    Electrical Characteristics

3.1    Range of Functionality

The following parameters must not be exceeded:

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3.2    Power Stage Electrical Specification

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3.3    I/O-Interface Signals Specification

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4    Connectors, Functions and Features

4.1    The HERKULES III Powerboard

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4.2    Operation Modes and LED functions

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4.3    Protection and Diagnosis Modes

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4.4    The PPM / I2C Breakout Board

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Each Individual ESC is protected against various failures. Each protection event is detected, stored and transmitted to the telemetry interface or saved on the MicroSD-card of the Telemetry interface.
The following protection mechanisms are implemented:

• Overvoltage Protection
• Overtemperature Protection
• Overcurrent Protection
• Control Signal Timeout
• Motor Stall Detection
• Setpoint Monitoring

The reaction of each ESC in case of detected Failure mode is described below:

4.3.1    Overvoltage Protection

The battery voltage is monitored and reported in the telemetry feedback data. In case it is higher than the V_OV_LMT (see Table 3 on page 12), the ESC refuses to start. This value is only checked after first power on and only in case the ESCs had not been started. If a voltage increase higher than V_OV_LMT happens during runtime, the ESCs are NOT switched off.

4.3.2    Overtemperature Protection

The temperature of each individual ESC is monitored and reported in the telemetry feedback data.
The over temperature protection has two detection thresholds.

1. V_OT_LMT : Power limitation to 50%
2. V_OT_OFF : Complete ESC switch off

In case the temperature is higher than the T_OT_LMT (see Table 3 on page 12) the ESC goes to a power limitation mode. The Motors are still running but the output power of the ESCs is only 50% of the actual requested power by the setpoint. When the ESC temp falls again below the T_OT_LMT minus a hysteresis threshold, the ESC output power limitation is switched off.

In case the temperature rises further after V_OT_LMT has been activated, the individual ESC is switched off completely and is locked until the motor setpoint goes below the Motor OFF detection threshold VAL_OFF_I2C (see Table 13 on page 99) or the Motor OFF detection Time T_HI_OFF_PPM (see Table 14 on page 101).

During over temperature switch-off, the affected motor “plays” an over temperature sound.

4.3.3    Overcurrent Protection

The current in each motor phase is monitored (not the Battery current!) and in case this current goes above the I_OC_LM threshold (see Table 3 on page 12), the ESC reduces the output power until the current goes below this threshold. The ESC does NOT switch off completely and keeps on working as long as the electronics can control the motor commutation correctly.
Overcurrent events might occur either:

1. Dynamically : e.g. during acceleration of heavy load motors with big propellers or
2. Statically : e.g. by a short circuit in the motor windings or motor wires.

A dynamic over current event leads “only” to a slower acceleration of the motor. The influence to the overall flight behavior will not be noticeable.

A static over current event will usually cause a stall (blocking) of the motor and this is detected by the stall detection see below.

4.3.4    Motor Stall detection

The motor control algorithm monitors the commutation times of each motor phase and in case of a detected abnormality a STALL event is detected. This event is reported also to the Telemetry Interface. The ESC goes to lock mode and is only re-activated when the motor setpoint goes below the Motor OFF detection threshold VAL_OFF_I2C (see Table 13 on page 99) or the Motor OFF detection time T_HI_OFF_PPM.

A Motor stall event could occur e.g. when a motor is blocked or propeller is mechanically locked or the bearings of the motor are defect.

4.3.5    Control Signal Timeout

The Motor control signal is monitored and in case of there is no control signal any more for a timeout of more than T_TO_PPM (see Table 14 on page 101) or T_TO_I2C (see Table 13 on page 99) the motor is stopped. This is mainly a safety feature in case of a broken PPM or I2C control wire. This ensures that the motor stops safely after this timeout.

4.3.6    Control Setpoint monitoring at first power-on

At first power-on the motor control setpoint is monitored and in case it is higher than the Motor START detection threshold VAL_START_I2C (see Table 13 on page 99) or VAL_START_PPM (see Table 14 on page 101) the motor refuses to start. Only when the setpoint value comes back below the Motor Off Detection Time, the ESC is initialized and enables a motor start when it is required by the motor setpoint.

This feature avoids a motor runaway after power-on in case of the motor setpoint is unintentional high e.g. by open wires or the flight control is not working correctly.

4.5    The HERKULES III Telemetry Interface

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4.6    The HERKULES III Precharger Module

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5    Software Update and Programming

5.1    Programmable Features

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5.2    Hardware Versions and Revisions

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5.3    Selecting the Firmware and Control Modes

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5.4    General Firmware Update Procedure

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5.5    The Programming Adapter

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5.6    Update Procedure HERKULES III Powerboards

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5.7    Update Procedure TELEMETRY INTERFACE

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5.8    Update Procedure DATALOGGER

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6    Application Examples

6.1    Setup with DJI Wookong (PPM Control)

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6.2    Setup with Mikrokopter FlightControl ME2.1 (I2C Control)

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7    RC Telemetry Systems

7.1    Graupner HoTT Telemetry

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7.2    JETI Duplex Telemetry

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7.3    Futaba S.BUS

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7.4    Spektrum Telemetry

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7.5    LOGVIEW Serial Protocol

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8    Analyzing Telemetry Data with LogView

8.1    Installation and Setup

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8.2    Importing Files

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8.3    Analyzing Data

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8.4    Available Channels

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8.5    Zooming, Tips and Tricks

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9    Control Protocol and Communication Interface

9.1    Overview

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9.2    I2C Address Range

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9.3    I2C Communication Sequence and Timing

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9.4    I2C-Mode : Setpoint Write and Data Read via I2C

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9.5    PPM-Mode : Setpoint Write via PPM and Data Read via I2C

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