Solid State Relays: Difference between revisions
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A Solid State Relay, or SSR, is an electronic device that uses low voltage input to switch high voltage on or off. It is used in Christmas displays to allow the controller to switch the lights on and off. This article will show one who is not familiar with the device a basic overview of how it works. | A Solid State Relay, or SSR, is an electronic device that uses low voltage input to switch high voltage on or off. It is used in Christmas displays to allow the controller to switch the lights on and off. This article will show one who is not familiar with the device a basic overview of how it works. | ||
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== Components == | == Components == | ||
Revision as of 03:19, 17 June 2007
Overview
A Solid State Relay, or SSR, is an electronic device that uses low voltage input to switch high voltage on or off. It is used in Christmas displays to allow the controller to switch the lights on and off. This article will show one who is not familiar with the device a basic overview of how it works.
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Components
There are a few basic components that make up a Solid State Relay.
Triac
A Triac is a semiconductor device which perfoms the actual switching of the High Voltage current. It is usually in a TO-220 package with three pins.
Optocoupler
The Optocoupler is a device that helps to keep high voltages out of the control board and computer. It consists of a small LED that is optically coupled to an sensor circuit. The controller powers the LED, which causes the sensor circuit to send power to the Triac. Because there is no electrical path from the controller to the High Voltage, the risk of damage is significantly reduced.
Fuse
The fuse is another safety device used in many designs to limit the flow of current through the board. It will blow out if an unsafe amount of current passes through it, preventing damage to the board or a fire.
Resistors
Solid State Relays also have resistors to limit the flow of current through certain components. The value of the resistor can be determined based on the instructions at SimpleIO