General Opto-coupler Notes - Voltage Multipliers, Inc.

Voltage Multipliers, Inc.
Opto-coupler Notes
Definitions
Opto: From the word “optics”, meaning the science of light and vision.
Example: Optical illusion, fiber optics.
Coupler:
From the word “coupling”, meaning a link or device connecting two things.
Example: A “coupling” between two railroad cars.
Gain:
What you get out divided by what you put in. (Output divided by input).
Example: Financial gain = Ending balance divided by total investment.
Example: Current gain = Output current divided by input current.
What is an opto-coupler?
An opto-coupler is a device used to electrically interface between two current- isolated systems. It does this by way of light transmission.
How does it work?
When connected in a linear regulator configuration, the external system supplies
current to the Light Emitting Diodes (LEDs). Refer to OC-100 and/or OC-250 data
sheet.
As the level of LED current fluctuates, so does the light intensity of the LED.
The light from the LED falls on the light- sensitive junctions of the high voltage diode.
The high voltage diode is reverse-biased, so that the leakage current through the
diode varies in response to the light levels from the LEDs.
8711 W. Roosevelt Ave. Visalia, CA 93271 Phone: (559) 651-1402
Fax: (559) 651-0740
http://www.voltagemultipliers.com
Voltage Multipliers, Inc.
General Maximum & Electrical characteristics
Block diagram - two main areas
· Light emitting diode - a.k.a. LEDs
Forward current
· Photo diode - a.k.a. HV diode, RZ 464 or Z100SG with thin glass
Reverse voltage
Absolute maximum ratings
Electrical characteristics
· LED
· Photodiode
Description of the OC-100 and OC-250 devices
Assembly methods
OC-100
The 10KV diode and two LEDs are precisely positioned in a mold and injection
molded with an optically clear potting material.
The diode is coated with a thin layer of glass, which makes the junctions more
sensitive to light.
OC-250
Three OC-100 assemblies are soldered together (in series) and potted
in a shell with a standard hard epoxy. Normal potting procedures are followed.
8711 W. Roosevelt Ave. Visalia, CA 93271 Phone: (559) 651-1402
Fax: (559) 651-0740
http://www.voltagemultipliers.com
Voltage Multipliers, Inc.
Physical characteristics
OC-100
A six leaded device containing one HV diode and two LED’s. The LED’s are positioned on either side of the HV diode to maximize the exposure of the junctions to light
emitted from the LEDs.
Approximate physical dimensions are 1" length x .45" width x .32" height.
OC-250
A four terminal device - two flying leads and two solder turrets - that contains three
HV diodes and six LED’s.
Approximate physical dimensions are 2.10" length x 1.40" width x 1.0" height.
Opto-coupler Advantages
·
·
·
·
High isolation voltage
High voltage (Up to 25KV)
Remote sensing
Excellent voltage gain ratio
Typical opto-coupler uses:
·
·
·
·
·
·
Elimination of ground loops
Interfacing circuits operating at different voltage levels
Increasing the noise immunity of a system
Reducing effects of electrical noise (motor control systems)
Protection of equipment & user from high voltages
Interfacing safe & hazardous areas in intrinsic safety applications
Typical opto-coupler applications
·
·
·
·
·
HV switching
Contact closure
External voltage sensing
HV isolation
Mass spectrometry
8711 W. Roosevelt Ave. Visalia, CA 93271 Phone: (559) 651-1402
Fax: (559) 651-0740
http://www.voltagemultipliers.com