The device can work in chopper (5 Hz – 10 kHz) or shutter (0 – 10 Hz) mode. The chopper mode is useful in phase-sensitve types of measurements.
This mode is used in phase-sensitive measurements. The device is easily integrated with any lock-in setup that sends or accepts TTL modulation signal.Click to zoom
In the shutter mode a two slots blade is used. The blade can stay in one position indefinitely or be switched on and off in the shortest time of 0.05 sec.
click the photo to enlarge
The main motivation of building our own chopper was the concern about electromagnetic emission from regular choppers. It disturbs or makes impossible low photocurrent measurements with our photoelectric spectrometers, potentiostats and Kelvin probes.
The high quality motors used in our device are double screened and the emissions are small.
The blades used by us are compatible with blades from Thorlabs.
Here are the basic properties of our product: