Do any of you know if this relay includes a back EMF diode across the coil contacts?
I would assume so since the coil pins are polarized but I just want to be certain because the spec sheet makes no mention of such diode.
Perhaps sign one out of stock and measure with a meter on the diode function. I’m quite sure if the diode is present the coil contact Vforward reading will be different when the leads of the meter are reversed.
No, that relay does not contain a diode. These are the Omron options that have a diode I don’t see a 3V option among these. These options from other manufacturers also include a diode. I was not able to find a relay with a 3Vdc coil voltage that contains a diode.
Ok, thankyou Jenny,
Hello jaspit,
These Omron G6K relays are an interesting technology that breaks the rules. Their small size and high efficiency necessitate design features not commonly found in other relays.
The G6K series is a telcom relay designed for militarization and high efficiency operation. One way to increase efficiency is to improve the coil design including geometry and wire resistance. I suspect designers reach a point of diminishing returns with materials and manufacturability. One option to further improve the situation is to add holding assistance using a small permanent magnet.
A consequence of this internal magnet is the need to apply the correct polarity to the relay’s coil. This is necessary so that the magnetic fields complement each other. My guess is that the G6K would toggle with incorrect polarity but would not meet specification involved with maintaining solid contact such as shock malfunction.
I’ve been unable to find direct proof that the G6K has this feature. However, it does fit the pattern of Omron’s “Moving Loop System” as described in this note:
I invite others to provide a definitive answer. Perhaps they could provide an explanation of the datasheet’s “External Magnetic Interface” section.
Best Wishes,
APDahlen
2 Likes
Polarized and non-polarized coils in DC relays are always easy to spot on the data sheet by looking at the part schematic. In this case the G6K data sheet shows the coils connections as polarized on pages 6-7.