Matrix Orbital LK162-12 Legacy - Manual (Page 16)

LK162-12 rev 4 16
Figure 2-8 General Purpose Outputs
Maximum allowable current is 20mA, which is enforced by the current limiting resistor. If the device being
switched has a resistance of 240 ohms or more the corresponding resistor may be shorted.
Note: The GPOs do not have any over current or over/under voltage protection so care must be taken when
using them. For instance if the external device is a relay it must be fully clamped (using a diode and
capacitor) to absorb any generated back electro -motive force (EMF).
10 - 100 uF
1N400 1
Relay
coil
GPO
+ -
Figure 2-9 Clamping a Relay