Solid State Relay Circuit Diagram

A wiring diagram is a simplified traditional pictorial depiction of an electrical circuit.

Solid state relay circuit diagram. A solid state relay ssr is an alternative to using a classic switch when you want to turn a circuit on or off. This article describes a simple project of a solid state relay which can be used in the place of electromagnetic relays. For driving more load you can use a higher value triac like bta41 or similar. A great point of a circuit like this is the seperation of the dc and ac voltages so this solid state relay circuit might be applied in many kind of applications up to around 15 kilowatt in case you mount the triac on a huge cooling ribthe m indicator noted on the triac means its a 600volt design a d stands for 400volt.

Solid state relay input. This article provides an introduction to the basic operation of solid state relays with a focus on the output devices in todays ssrs. Solid state relay ssr can be controlled directly by npn type or pnp type transistor as shown in circuit diagrams a and b below. Circuit design of solid state relay.

A solid state relay circuit with in built zero crossing detector is described in this article. The circuit can be easily drive ac load of 1000 watt. The opto isolator isolates the input from the output. It shows the parts of the circuit as streamlined forms as well as the power as well as signal connections between the devices.

In the diagram a vt is open at ordinary time and ssr is in on state. Pin 2 of moc3021 is connected to ground through a current limiting resistor. A suitable heat sink is a must for any traic you are using. Solid state relay solid state relay is a hybrid circuit normally composed of an optocoupler which isolates the input a trigger circuit that detects the zero crossing of the line current and a triac or similar device that acts as a circuit breaker.

There are many circumstances in which we need to control a high currentvoltage load based on the operation of a low power circuit such as when using the 5v output of a microcontroller to turn on a 10a 240v load. The ssr is triggered by an external voltage applied across its control terminal. Pin 6 of moc3021 is connected to t1 pin 1 of triac bt136 with a 100 resistor. Variety of solid state relay wiring diagram.

The circuit is very easy to understand and build yet provides with useful features like clean switching free from rf disturbances and able to handle loads up to 500 wattswe have learned a lot about relays and how they function. Pin 4 of moc3021 ic is connected to gate pin 3 of the triac.