300CD Rotating Optical Chopper
Features
Scitec Instruments Model 300CD is a high stability variable frequency optical chopper. The basic system consists of a control unit, a chopping head and a set of four chemically blacked photo etched discs. This system provides operation over the frequency range 5Hz to 3kHz. A wide selection of additional discs and accessories is available to extend the frequency range and to satisfy individual requirements.
• 5Hz - 3kHz standard optical chopping frequency range (0.015Hz to 40kHz options are available)
• 102mm diameter discs
• Choice of control units
• Compact optical chopper head
• Low noise and vibration
• Photochemically etched non-magnetic discs
• Variable aperture
Range of accessories
Tthe 300CD control unit has a 5-digit display of the chopping frequency. Chopping frequency can be controlled externally by applying an analogue voltage to a "Control" BNC. A "Reference" BNC provides a TTL level output, generated directly from the opto-switch on the chopping head. This signal has constant phase relative to the chopping action and can be used as the reference for other instruments such as lock-in amplifiers.
The 300H optical chopper chopping head supplied with the standard system may be bench bolted or optical stalk (bench rod) mounted. Mountings are provided to enable parts, such as a high frequency accessory or blade protector, to be attached. For lower frequency operation, the chopper head can be fitted with a reduction gearbox motor.
The set of four chopping discs included with the system (part number 300D) provides a choice of 2, 5, 10 and 30 slots, each having a 1:1 mark to space ratio. Variable apertures can be achieved by mounting two identical discs simultaneously. Additional discs, with up to 445 slots, are available to extend the chopping frequency up to 40kHz. Although the standard discs are chemically blacked other finishes, such as gold plating, are available.
Specifications
300CD Control Unit
Output Voltage: 15V DC Maximum.
Stability: ±0.01%/°C
Frequency Control: Internal - Manual Control via 10 turn potentiometer. External - BNC connector for 0 to 15V.
Frequency Read Out: 5 digit 14mm LED display with 0.01Hz resolution, 0.1Hz or 1Hz resolution depending on frequency.
Frequency Stability: Short term - see phase jitter. Long term - ±0.1% of maximum frequency.
Reference output: 5V HCT TTL signal via BNC socket.
Power Requirement: 100-130V or 200-260V AC, 50 or 60Hz, 12 VA.
Dimensions: 254(W) x 76(H) x 178(D)mm
Weight: 2.6kg
300H Chopping Head
Moter: 11 pole DC motor, sleeve bearings with more than 6000 hours lifetime, 0-6000rpm reversible.
Reference pick-up: IR led and phototransistor pair with Schmitt trigger.
Dimensions: 73(H) x 75(L) x 32(W)mm, without disc.
Mounting: Optical stalk - adjustable between 6.5 and 14.0mm diameter. Mounting holes - 2 x 3mm
300D Set of Chopping Discs
Disc types: 2, 5, 10 and 30 slot
Material: Half hard brass, 0.5mm thick
Diameter: 102mm
Surface Finish: Chemically blacked
Mark to Space Ratio: 1 to 1 with one blade
Frequency Range:
Disc
Frequency (Hz)
Aperture
Phase Jitter, Max
r
a
b
d
300D2(2 slots)
5 - 200
32.0
77.0
26.7
32.0
±0.2°
300D5(5 slots)
12.5 - 500
32.0
30.8
10.7
23.1
±0.5°
300D10(10 slots)
25 - 1000
32.0
15.4
5.4
13.2
±1°
300D30(30 slots)
75 - 3000
32.0
5.1
1.8
4.8
±3°
Ordering Information
Model 300CD
A complete optical chopper system with frequency display includes: 300CD Control Unit, 300H Chopping Head, 300I Interconnecting Cable, 300D Set of Chopping Discs and IEC mains lead.
商品属性 [频率] 5Hz to 3kHz