Need relay that operates with 3.8 VDC input.

[Sensor One]

Hello,
I have an input of 3.8 VDC and I am looking for a relay that I can use. I have seen only 5VDC relays and I am wonder if I can use the 5VDC using 3.8VDC as input.
Thanks,

 

[Audioguru]

The datasheet for every relay shows its minimum pull-in voltage. I haven't used a relay for about 45 years so I cannot remember if it is a certain ratio of its nominal voltage.

 

[hevans1944]

If you can find 5 V somewhere (maybe the circuit from which your 3.8 V DC is derived) you can use it to power the relay through a transistor switch controlled by your 3.8 V DC. If the raw DC supply voltage is much higher than 3.8 V DC, you can use a relay with a higher coil voltage, still controlling it with a transistor. Either way, a diode across the relay coil is required to protect the transistor from coil back-emf that occurs when the transistor is turned off after conducting to energize the coil.

You might also want to try this relay with a 3 V DC coil for reliable operation from 3.8 V DC, with or without a transistor switch.

 

[Alec_t]

What do you want to control with the relay? Have you considered using a solid state switch instead of the relay?