1.Automatic meter reading
The needs of centralized remote meter reading systems for water, gas and electricity in medi-um and high rise apartments and new subdivi-sions are now increasing. PhotoMOS are capable of controlling from low level signals up to power signals and feature low leakage current and noise from the optoelectronic de-vice and power MOSFET combination.
2.Telecommunications
A variety of signals, with levels from millivolts (at microamperes) to tens of volts (at several hundred milliamperes), AC or DC, and even high bit-rate signals, can be superimposed on telephone lines, the heart of telecommunica-tion networks. The switches in telecommunica-tion circuits, which normally carry DC signals, also carry AC signals on top of the DC level when an intermittent signal (e.g. ringer signal) is being sent. PhotoMOS are capable of controlling small level (millivolts at microam-peres) AC or DC signals.
3.Instrumentation
With the spread of microcomputer chips, the latest instruments are required to measure a variety of signals at high speeds under various conditions. PhotoMOS are recommend-ed for measurement scanning functions, auto-matic zero-point compensation to eliminate zero-point error, and measurement sequence interfaces (e.g. alarm interface.)
4.Medical equipment
Medical equipment which processes low level signals includes electrocardiographs, electro-encephalographs, and X-ray CT scanners. PhotoMOS accurately transfer low level signals (less than several hundred millivolts). Furthermore, they are also convenient in driv-ing rotary solenoids such as those used to au-tomatically switch voltage ranges.
5.Communications equipment
The future of communications is in satellite communications. Satellite-communications feature many advantages such as indifference to terrestrial disasters, wide service areas, sim-ple circuit modification and simultaneous con-versations. An important control operation in communications equipment is fast automatic tuning. PhotoMOS can easily be connected in parallel, difficult with conventional transistor type. As a result, a variety of circuit connection are possible and power circuits can also be de-signed.
6.Programmable controller
The output circuit of a programmable controller requires various interfaces to match the load type. Recently, as the computing speed and data processing speed increase, problems may arise from noise at the input interface as well as at the output interface. PhotoMOS are resistant to inrush cur-rent (due to phase shift) and eliminate the need for snubber circuits as long as they are operat-ed within the ratings. Furthermore, use of PhotoMOS decreases the mounting area requirements, resulting in more compact pro-grammable controllers.
7.Security Equipment
There are many types of security systems from home and office security to building security.
PhotoMOS are ideal for use as input in-terfaces for system sensors and output inter-faces for alarms.
Input interface: Low leakage current makes use possible for low level voltage and current input.
Output interface: Outputs either AC or DC up to a load voltage of 400 V.
8.OA equipment
OA equipment usually contains a sensor con-trol unit (for temperature, speed, torque, etc.), drive unit, power supply unit, and a processing unit which controls the overall system. It is or-ganized similarly to compact factory automa-tion machinery. PhotoMOS have wide application in the interfaces for signals which connect the functions of these units.
- Operates on a 24 mW input to enable direct control of C-MOS devices.
- Signal transfer through optical coupling achieves high resistance to noise and tran-sients, eliminating the need for adding a snubber circuit to the output to control the load voltage.
- Advantages in the total cost and reliability in the control system result from the absence of AC leakage current related to the snubber cir-cuit.
