Isonas OCZRC-04M, Как установить

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How to Install the ISONAS PureIP Reader-controller
2.2.15: MANAGING INDUCTIVE LOAD CHALLENGES
Most door latches use a relay coil that powers up and down, when the door is unlocked and
locked. When this happens, a pulse of electrical energy is produced by the lock’s coil. This pulse is
called back EMF, and can interfere with the reader’s operation.
Switching off a typical 12 VDC relay coil can produce a back EMF pulse of 300 volts or more. If this
voltage pulse is allowed to flows back into the reader, it can cause the reader to “brown out” and
the reader will reboot.
Figure 13 shows a solution. You can virtually eliminate back EMF by installing a transient
suppression device (diode). Each Pure IP Reader-Controller is supplied with a diode assembly,
which simplifies the installation process. A standard diode, from any electronic supply store, can
also be used. Always check that the diode is correctly rated for the circuit voltage. For optimum
performance, the diode should be installed at the lock or close to the lock. Standard diodes have a
stripe-band marking on one side. That side of the diode should be connected to the “+” wire of the
lock circuit.
Figure 13
Protect the Digital
Output
Which type of transient
suppressor should you
install? This depends
mainly on the type of
inductive load being
switched. Some locks
have Back EMF protection
built into the lock itself.
For Back EMF in low-
voltage DC applications, a
1N4007 diode will suffice.
However, for protection
against other transient
voltages (i.e. lightening),
we recommend using a
fast-switching transient
voltage suppressor, such
as a bipolar TranZorb.