Inrush current of relay coil??? Can we use a cld?

Status
Not open for further replies.

fastline

Member
We are building a circuit to drive a power relay. Typically someone would use the old 30/40A "icecube" relay for this at is common in automotive. We have verified that they pull 200mA continuous but more concerned with the inrush current blowing our driver or CLD if we can use one. We really want to limit the current some how to protect against a short circuit but wondering if CLDs have any transient ability.
 
Relay coils are inductive so there is no inrush current, the current actually increases exponentially due to the inductance.

You do have to put a diode across the coil (cathode to positive end) to suppress the turn-off voltage transient or it will zap your driver.

What is a CLD?
 
CLD = current limiting diode. We would like to limit and protect the amount of current available for this output. My concern was in inrush that would zap the diode.
 
What InRush current??? Look at the red trace which is the current through the coil.

The only thing that exhibits "InRush" is charging a capacitor, turning on an incandescent lamp, or starting a motor.
 

Attachments

  • DF55.png
    34.7 KB · Views: 263
Last edited:
Status
Not open for further replies.
Cookies are required to use this site. You must accept them to continue using the site. Learn more…