Latching Relay Circuit

These are very useful in situations where energy efficiency is important but also in sitations where you need the relay to remember its state typically so that the user can press a button to close the.

Latching relay circuit.

An earth leakage circuit breaker includes a specialized latching relay. Resistor r2 and r3 prevents the short circuit in this condition. An electrically latched relay is a standard relay with one of its own contacts wired into its coil circuit. When we press push button supply goes to relay a1 point and relay gets on and its contact changes but when we release push button supply cutoffs and relay gets off.

Here i demonstrate a circuit which is a simple asynchronous sr latch using a relay. This is normal behaviour until now but what makes it a latch circuit. These are very useful in situations where energy efficiency is important but also in situations where you need the relay to remember its state typically so that the user can press a button to close the relay and press a second button to open the relay again. Even after the input voltage is interrupted this relay maintains its set or reset condition until it receives the next inverting input.

This is achieved when an electromagnetic current generated by the electrical input from the first device attached to the relay causes the contacts in the switch to open or close. It is a relay that is set on orreset off by the input of a pulse voltage. Geya latching relay circuit draws power during the brief voltage pulse required to make it change state. What is a latching relay.

There are two kinds of latching relays. A stepping relay is a specialized kind of multi way latching relay designed for early automatic telephone exchanges. A general purpose relay switch is designed to function as a bridge on one or more connected devices or circuits receiving an input signal from one source and transmitting an on off set reset output to another. Relay latching circuit using push button we connect relay and push button as per figure.

Very early computers often stored bits in a magnetically latching relay such as ferreed or the later remreed in the 1ess switch. In our case led will glow. Now when base of transistor bc557 gets grounded it starts conducting and energises the coil of relay which activates the relay and turns on the device connected to relay.