The Low cost VARIABLE FREQUENCY Shutters/Choppers Models CH-60 and CH-61 consist of a blade (vane) mounted on a motor with a limited rotation angle. The position of the blade follows the direction of the current in the motor winding. Current in one direction sets the shutter to the open position and current in the other direction sets the shutter to the close position. Alternating the current cause the blade to open and close the chopper at a frequency range from DC to 50 Hz for the CH-60 and CH-61. This method of chopping is jitter free. High reliability and long life is achieved by eliminating the use of a brush type motor or gear heads. The device can be used at the same time as a shutter that is controlled by the direction of the current. The shutter / chopper is especially suitable for low cost dedicated applications, OEM, built into an instrument/system, and for portable systems.
| CH-60 (when used with the DCH-60 Driver) | CH-61 (when used with the DCH-60 Driver) | |
| APERTURE SIZE | 0.25" × 0.45" (6.3mm × 11.4mm) | 0.31" dia. (8.7mm dia.) |
| FREQUENCY RANGE | DC to 50Hz | DC to 50Hz |
| RESPONSE TIME (from an OPEN position to a CLOSED position, or vice-versa) | 10 mSec | 10 mSec |
| FREQUENCY STABILITY | 0.1% internal clock, 0.005% with external crystal clock input | 0.1% internal clock, 0.005% with external crystal clock input |
| EXTERNAL CLOCK INPUT (5V or "OPEN" to open the shutter, 0V or "GND" to close the shutter) | DC to 50Hz TTL level input | DC to 50Hz TTL level input |
| SETTLING TIME TO EXTERNAL CLOCK | 20 mSec | 20 mSec |
| MONITOR OUTPUT | TTL level output ("High" indicates the shutter is open, "Low" indicates the shutter is closed) | TTL level output ("High" indicates the shutter is open, "Low" indicates the shutter is closed) |
| POWER REQUIREMENTS (Standard) | CH-60 and driver board: 15V dc, 250 mA | CH-61 and driver board: 15V dc, 250 mA |
| POWER REQUIREMENTS (with IR EMITTER option) | CH-60-IR (an IR EMITTER option) and driver board: 15V dc, 250 mA & 5V dc, 1.0 Amp | CH-61 does not offer an IR EMITTER option |
| SHUTTER SIZE | 1.75" W × 3.0" H × 1.0" (1.90"W × 3.0" H × 1.25"D boxed) | 1.75" W × 3.0" H × 1.0" (1.90"W × 3.0" H × 1.25"D boxed) |
| SHUTTER WEIGHT | 2.5 Oz (70 grams) | 2.5 Oz (70 grams) |
| OPERATING TEMPERATURE | 0 - 65°C | 0 - 65°C |
Using our DCH-60 driver with the "MODE" selector switch provides two modes of operation for the CH-60 chopper/shutter: internal mode and external mode. In the internal mode the CH-60 is used as a variable low frequency chopper. The chopping frequency is set by an internal oscillator adjustable from 1 Hz to 50 Hz. In the external mode the CH-60 is used as a chopper or as a shutter and is controlled by an external TTL signal input. "high" input keeps the CH-60 open , "low" input keeps it close. Response time is 10msec. Maximum frequency for TTL input is 50Hz. The chopper is especially suitable for low cost dedicated applications, OEM, built into an instrument/system, and for portable systems.
The DCH-60 driver is designed pecially for model CH-60 and model CH-61 chopper/shutter.
THE DCH-60 DRIVER CONFIGURATION:
The DCH-60 Driver is available in two configurations:
Model DCH-60-PC: A board level driver
Model DCH-60-110 or -220: A cased driver, 5.3" x 5.3" x 2"
Operating from a line voltage of 110V ac or from 220V ac
SPECIFICATIONS (When used with the DCH-60 Driver)
APERTURE SIZE: 0.25 X 0.45 inch
FREQUENCY RANGE: DC to 50Hz
RESPONSE TIME: 10 mSec, from an OPEN position to a CLOSED position, or vice-versa
FREQUENCY STABILITY:0.1% internal clock
0.005% with external crystal clock input
EXTERNAL CLOCK INPUT: DC to 50Hz TTL level input
5V or "OPEN" to open the chopper/shutter
0V or "GND" to close the chopper/shutter
SETTLING TIME TO EXTERNAL CLOCK: 20 mSec
MONITOR OUTPUT: TTL level output
"High" indicates the chopper is open
"Low" indicates the chopper is closed
POWER REQUIREMENTS:
The CH-61 and driver board: 15V dc, 250 mA
CHOPPER SIZE:
1.75" W X 3.0" H X 1.0" D
(1.90" W x 3.00" L x 1.25" D boxed)
CHOPPER WEIGHT: 2.5 Oz (70 grams)
OPERATING TEMPERATURE: 0-65 deg C
