Turbine Control Unit

All parameters of the controller are user adjustable. This means that the user can adjust idle and maximum speeds, adjust starting revs & temperature, full speed rev & temperature shutdown points, ramp rates, ramp switch points, etc. The TCU 'learns' the pulse size from the R/C system. We do not dictate to the user what his settings should be (i.e. EGT or maximum revs).

Slow ramp on initial start up of turbine. The pump starts at tick over, increasing over a user adjustable ramp rate to idle speed. This reduces the possibility overheating of the NGV / turbine areas. If a (user settable) high temperature is reached, the TCU will stop incrementing fuel feed until the EGT returns to a safe level, then it will continue with ramping up.

Ramping times for normal operation are user adjustable (both up and down ramping) with the setting of up to three different ramp rates for increasing revs plus three different ramp rates for decreasing revs. This means for instance, that if a user has a problem with flame outs at low revs while decreasing the throttle, the TCU can be programmed to decrease the fuel feed over a longer period of time than while running at higher revs. Another benefit is being able to set longer ramping while moving from idle to for instance 1/4 throttle (this would reduce the chance of overheating the NGV / turbine area) at this critical part of the throttle curve.

If selected, the controller will auto adjust for full speed revs, useful especially on initial setup of controller/pump/turbine combination.

Run time and number of starts counter - useful for checking lifetime of bearings, flight time, etc. - user can zero when necessary (i.e. after a bearing change).

Pulses per rev can be adjusted for 1 or 2 pulses, dependent on the preferred method of speed measurement, however, the recommended method of speed measurement is the magnetic system although IR sensors are catered for with the TCU.

The TCU allows for the pump to be primed without having to simulate turbine inputs. This allows the user to circulate fuel in order to ensure that all air is removed from the fuel supply system, which leads to very smooth flame free starts.

The TCU supplies power for the glow plug. Switching is done automatically and efficiently in order to conserve available battery power. Glow plug fail detection is reported via the SDU.

AutoStart can be enabled or disabled by the user. This allows you to get up and running using manual start and once you are happy with the way your motor starts and runs, you install a starter motor, enable AutoStart and watch things happen. Gas switching is via a solenoid-operated valve. Gas and starter motor switch off points are user adjustable. Auto cooling after a run is enabled with the AutoStart option. This will cycle your turbine until the EGT is below 120' C. The TCU will operate with a battery supply range of 3 - 10 volts (6 cell, 7.2v battery pack recommended for AutoStart version on KJ66 type motors, 3 or 4 cells recommended for MW54 motors).

The Turbine Control Unit is supplied as a complete system, consisting of: TCU, SDU, thermocouple, speed sensor and magnets as well as an extensive manual with step-by-step instructions for setting up and using the system. No "optional" extras have to be purchased, however a

Remote magentic sensor board is available. This board is sensitive to detect a magnet in the spinner nut while being mounted behind the compressor inlet. A washer magnet is supplied with this board.

An OnBoard display unit is available which displays the status of the TCU via 4 LED's. Indications are: Revs not reached, EGT not reached, Shutdown, Start Allowed, Running, spooling up and cooling cycle in progress.

Enabling the start sequence can be initiated from the SDU or from your radio control throttle, without the use of extra (valuable in jet aircraft) channels.

The turbine speed is measured and used to limit the fuel flow in the event of a high limit of RPM. Should the RPM continue to increase for some reason, the unit will shut off the fuel pump (and therefore the turbine) should a second higher limit be reached (this to prevent dangerous conditions and possible catastrophic failure of rotating parts). Low-end revs are also monitored; the fuel pump will be shut down in the event of the RPM falling below a minimum limit (in case of flame out, seizure, etc.) thus preventing fuel flooding the aircraft.

The EGT is measured, and will limit the fuel pump drive should a high limit be reached, and will not allow an increase until the temperature has reduced to a safe value (allows fastest safe spool up times). Should the temperature continue to increase above a second higher value, the TCU will shut down the turbine with immediate effect to prevent damage to your motor / aircraft. Low EGT is monitored and will shut the motor down if it falls below a user adjustable value. EGT is also used to enable the fuel pump on startup.

Shut down will occur if the input from the R/C system is reduced to minimum setting i.e. shut down position from the radio transmitter.

Loss of R/C signal or invalid pulse sizes for approximately 1 second will cause a shutdown.

Starting will terminate if the turbine is not running after a number of start attempt cycles.

If a 'step' takes too long to reach preset limits, a 'step fail' indicator will flag that a problem has occurred and will terminate starting.

Our AutoStart has been tested both at sea level and at 5550' ASL, and has worked successfully at these altitudes.