I'm designing a circuit where an ESP8266 controls two types of relays, a single coil latching relay and a normal non-latching relay. The relays are power relays use to control low power electrical appliances such as lights and fans. As the relays will be controlling 240V AC lines, I want to design a driver circuit with optocouplers to isolate the ESP8266 from the relays. Based on my research I have come up with a driver design for each type of relay as shown below.
These are the components that I'm planning on using :
- Non-Latching Relay (G5SB-14 DC5)
- Single Coil Latching Relay (SCHRACK PE014F05)
- Darlington Optocoupler (MOCD223R2M)
This is pretty much the common driver circuit for a simple non-latching relay. However, most driver circuits wire the optocoupler to another transistor which then drives the coil. Since I'm trying to save some space I was wondering if its possible to use a darlington optocoupler instead which can handle the high currents from the relay coil?
I'm not very confident with the driver for the single coil latching relay as its not very common. Hence, will this circuit work? Will the lack of diodes cause any long term effect to the circuit?
I'm hoping for this circuit to be able to last long and be durable. Any kind of advice and help will be much appreciated. Thank you in advance.