ELECTRO-OPTICAL PRODUCTS CORPORATION
	62-40 Forest Avenue, 2nd Floor • Ridgewood, NY 11385, USA • Tel: 718-456-6000 • Fax: 718-456-6050 • www.eopc.com

Optical Shutters/Choppers

		CH-50  CH-60  CH-61 DESCRIPTION CAD DRAWINGS

FEATURES AND ADVANTAGES Frequency from DC to 50 Hz Low Cost Aperture 0.25" × 0.45" (6.3mm × 11.4mm) or 0.34" (8.7 mm) dia. Jitter free operation High frequency stability (to 0.005%) Small size Withstands shock and vibration High reliability, long life Accepts external clock input Phase locking to an external input Can be stopped in the "ON" or "OFF" position No radiated electromagnetic interference (EMI) Bright or dark blade Integrated IR emitter (BLACK BODY) optional Special pricing for OEM applications

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The VARIABLE FREQUENCY shutter/chopper Model CH-50, CH-60, and CH-61 consists 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 will set the shutter to the open position and current in the other direction will set the shutter to the closed position. Alternating the current will cause the blades to open and close the chopper at a frequency range from DC to 12 Hz for the CH-50, or 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.

When used with our DCH-50 or DCH-60 driver and an external clock input, a frequency stability of 0.005% is possible. This ultra high stability cannot be achieved with a rotating chopper. The chopping operation is locked in phase to the clock input; no additional circuitry is needed for phase locking. The driver also enables the user to set the shutter in either a closed or an open position when it is not running.

The shutter/chopper is especially suitable for low cost dedicated applications, OEM, built into an instrument/system, and for portable systems.

SPECIFICATION	CH-50   (when used with the DCH-50 Driver)	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)	0.25" × 0.45" (6.3mm × 11.4mm)	0.31" radius (8.7mm radius)
FREQUENCY RANGE	DC to 12Hz	DC to 50Hz	DC to 50Hz
RESPONSE TIME   (from an OPEN position to a CLOSED position, or vice-versa)	30 mSec	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	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 12Hz TTL level input	DC to 50Hz TTL level input	DC to 50Hz TTL level input
SETTLING TIME TO EXTERNAL CLOCK	60 mSec	20 mSec	20 mSec
MONITOR OUTPUT	TTL level output ("Hi" indicates the shutter is open, "Lo" indicates the shutter is closed)	TTL level output ("Hi" indicates the shutter is open, "Lo" indicates the shutter is closed)	TTL level output ("Hi" indicates the shutter is open, "Lo" indicates the shutter is closed)
POWER REQUIREMENTS   (Standard)	CH-50 and driver board: 5V dc, 0.30 Amp	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-50 with an IR EMITTER option and driver board: 5V dc, 1.2 Amp	CH-60 with an IR EMITTER option and driver board: 15V dc, 250 mA & 5V dc, 1.0 Amp	CH-61 with an IR EMITTER option and driver board: 15V dc, 250 mA & 5V dc, 1.0 Amp
SHUTTER SIZE	1.3" W × 2.5" H × 0.85" D	1.75" W × 3.0" H × 1.0" D	1.75" W × 3.0" H × 1.0" D
SHUTTER WEIGHT	1.5 Oz (42 grams)	2.5 Oz (70 grams)	2.5 Oz (70 grams)
OPERATING TEMPERATURE	0 - 65°C	0 - 65°C	0 - 65°C