Matrix Orbital GLK12232-25-SM Legacy - Manual (Page 12)

12
G2
G1
GND
load
+5V gnd
load
GND
Note: load must be 250 ohms minimum
Figure 2-2 Using the General Purpose Outputs
If the device which is being driven by a GPO requires a relatively high current (such as a relay) it must have
an internal resistance greater than 250 ohms, or must be current limited to 20 mA by means of a suitable
resistor.
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
1N4001
Relay
coil
G2
GND
+
Figure 2-3 Clamping a Relay