Lock Connection

Electromagnetic spikes can affect normal system operation and in some cases, damage hardware. You must use a diode every time a coil, lock, or relay, is controlled.

When the lock is de-energized from 24VDC, the diode absorbs the "Inductive-Kick". All the energy that the locks coil has to "free" is absorbed by the diode. When the lock is de-energized from 24VDC, there is no diode to absorb all the energy that the coil has accumulated. This energy has to go somewhere, in this case, there is no diode to absorb the energy, so it goes in the cable. Note that voltage goes as low as -300VDC. These high spikes can cause electromagnetic disruptions and may affect the normal operation of the system. Even worse, it may damage equipment that is not protected by a diode.