![](https://croydonmrs.org.uk/wp-content/uploads/2018/11/relay.png)
Relays were first invented in 1833 and used to be a principal component in telephone exchanges. These devices are very useful in model railways. This workshop will cover the following topics:-
- What is a relay?
- Types of relay
- Relay terminology e.g. DPDT
- Use in model railways