In a MOSFET based relay, both AC and DC signals can be switched. The output utilizes two n-channel type MOSFETs. When controlling an AC load, one of the MOSFETs is used to switch the positive phase of the AC cycle while the other is used to switch the negative phase. When controlling a DC load, only one MOSFET is needed, and the relay can be configured to enhance switching characteristics.
The purpose of this report is to expose and clarify the basics of telephone line communication. It will analyze the different phases of a typical telephone call and display how solid state technology can be used in these different phases. The report will include how existing products offered by Solid State Optronics, Inc. relate to the telecommunications market. Finally, the report will describe new products being developed by SSO that have been designed specifically for the telecommunications industry.
A typical 1 Form A / 1 Form B relay consists of a normally open switch and a normally closed switch within a single package. Each relay is controlled by its own separate input LED. A typical application of a 1 Form A / 1 Form B relay is a situation where a design engineer would like to operate two servo motors, each with its own controlling input signal. The advantages of using a 1 Form A / 1 Form B relay instead of a single 1 Form A relay and a single 1 Form B relay in this case would be cost and space savings.
Solid State Optronics (SSO) AC relays have been designed with a driver circuit that controls the operation of two back-to-back silicon controlled rectifiers (SCRs), each responsible for switching one half of the AC cycle. If an AC signal is examined, the turn on, turn off, and zero-volt switching characteristics can be shown.
Solid State Optronics (SSO) provides a broad range of optically isolated devices designed for telecommunications applications. SSO’s TR115, one of the telecom relays, is designed to help perform the important function of loop current detection.
The purpose of current limiting is to prevent any transient current spikes or fault conditions from damaging the relay and any circuit components “downstream” from the relay. Current limiting technology has been designed into a variety of Solid State Optronics (SSO) relay products. This application note is designed to provide insight into the technology of current limiting and how it can be utilized for certain applications.
In a relay’s most basic function, the switching of a load circuit is controlled by a low power, electrically isolated input signal. In the past, Electromechanical Relays (EMRs) have been the component of choice, largely due to price, function, and availability. Now, however, the emergence of semiconductor technology has provided the means to manufacture solid state relays (SSRs) which in many applications outperform their predecessors.
High temperature is a common environmental stress in many solid state relay applications. Application engineers must have a solid understanding of how a relay can be expected to fail if the temperature exceeds the rating of the package. This paper aims to compare the theoretical and experimental failure modes of SCR-output relays vs. MOSFET-output relays at high temperature.
Isolation amplifiers are used in a wide variety of applications, including telecommunications, industrial, instrumentation and medical systems. The function of an isolation amplifier is to preserve or amplify a signal across a barrier of galvanic isolation.
The primary function of a modem data access arrangement (DAA) is to provide a path for the transmission of data from a high-voltage tip-to-ring phone line through an isolation barrier (typically 1500 VAC) into the modem for further processing.
The Solid State Optronics (SSO) product line consists of a broad range of optically isolated switching devices available in a wide assortment of packages. This application note provides SSO reference guidelines for various soldering methods and their recommended profiles.