rdub
Electrical
- Feb 10, 2004
- 27
With most "typical" dc coil applications (< 1amp) I've encountered, a diode is connected across the coil (directly to the supply) to absorb the surge when the coil is de-energized. I ran across an application where DC power was being switched (both + & -) through another relay. The diode was located between the + & - on the load side of the relay. Therefore, when the relay opened, only the diode was connected across the field device coil. I initially thought this was a bad idea - it would increase the turn-off time of the field device but now I'm thinking it probably doesn't matter. Any thoughts?