The stepper motor filter wheel/shutter is a microprocessor half step motor driver capable of operating up to two six position filter wheels and three high speed shutters.
The LEP stepper filter wheels are driven by stepper motors via a timing belt. An integral home position (Hall Effect) sensor is utilized for automatic initialization. The maximum speed is 100ms between adjacent filter positions.
Filters can be easily inserted and removed from the filter wheel while the entire assembly is mounted on the microscope due to the hinged construction of the filter wheel.
Up to three high speed shutters may be controlled using the same module. The drive electronics utilize a bi-level drive, supplying an initial high opening voltage for high-speed action (<15ms to open or close) followed by a lower holding voltage which allows shutters to be held open indefinitely without damage. Manufactured specifically for high temperature applications, these shutters have proven to be extremely durable under heavy usage due to their simple design.
Triggering Options:
- High speed synch mode where a TTL output signal may trigger an image capture after a filter position change.
- Sequencer macro function to simplify repetitive filter movements.
- External TTL signals may be used for shutter synchronization.
Front Panel Control Functions
The filter wheel module allows manual control of key filter wheel/shutter functions using five switches located on the front panel. A user may control the state (i.e. open or closed) of three shutters simply by using the toggle switches which are labeled SH1, SH2 and SH3. Note: Software control overrides the front panel switch setting. Indicator LED's on the front panel illuminate to signify that a shutter is open and darken when the shutter is closed. The filter position of filter wheel 1 and filter wheel 2 may be changed using the toggle switches labeled MAIN and AUX; the wheel will respond with a sequential movement dependent on the direction which the switch was toggled. Both wheels may be re-initialized to the"HOME" position by depressing the move switch down and holding for 4 secs.
Rear Panel Connections
Connections are made at the rear panel of the MAC 6000 module via a DB-15 female connector labeled Filter wheel 1 and Filter wheel 2. Each filter wheel/shutter combination requires a separate 15 pin cable. Most filter wheels are manufactured with a single internal shutter and auxiliary shutter. The auxiliary shutter may be added to the system by connecting to the 7 pin AUX port on the filter wheel housing.
