R02.1
07/01/2021
Page 7
2
Description of the device
General
The electronic frequency control device SIGA is used to realize a continuous control
of inductive loads like spiral conveyor, linear conveyor and hopper.
The control device works according to the pulse-width modulation (PWM) within the
half waves, the period can be adjusted between 20Hz and 99 Hz. The transporting
capacity can be diversified by setting the magneto-motive force via the input key-
board to a value between 10 - 99%. You can also pro-gram via the keyboard that the
nominal value can also be adjusted via an external analogue tension 0-10VDC, ana-
logue current 4-20 mA or a potentiometer.
The width of the sinusoidal output voltage (half waves) depends on the period ad-
justed and is thus constant. The width of the clocked impulse in this sinusoidal output
voltage can be adjusted stepless in the range of the positive resp. negative half wave
via keyboard input or via the externally determined nominal value. This adjusts the
voltage-time surface of the out-put voltage. For oscillating conveyors the oscillating
frequency can be adjusted variably between 20-99Hz, in the standard configuration
the adjustment will be made via the keyboard.
When the operating voltage has been switched on the integrated, adjustable smooth
start will be made after a forced dead time and guarantees a smoothened run up of
the output voltage up to the adjusted voltage level. Via a limiter stage at the switch-
on moment the charging current is limited to capacities of 4A. This eliminates possi-
ble switch-on peaks. Also the smooth start as well as the smooth run-out will become
effective via the control input or the keyboard when the output voltage is switched on
or off. In this way the transporting capacity can be increased or decreased in a time-
dependent way. So bulk material that has already been positioned will not lose its
position. Both time values can be adjusted separately.
The control input makes it possible to have the device switched on or off by another
system (SPS, approach switch, sensor etc.)
The control device provides its own supply voltage of +24 V DC for this purpose. It is
also possible to switch the device on or off via external voltage of + 24 VDC. This in-
put internally influences the PWM.
The control input control the runtime of the oscillating conveyor in a way that avoid
unnecessary runtimes.
You can determine via the keyboard whether the device is to work in the opener
mode or in the closer mode.
NOTE
Miniature magnets can also be operated safely at the IRG 1-S con-
troller!
