Velleman projects K2579 Assembly instructions - Manual (Page 9)

9
Hook-up and use
 Connect the unit with a 12VDC regulated power supply as shown in the example.
 Turn the trimmer all the way counterclockwise.
 Push the START button. The relay will be activated momentarily.
 The position of the trimmer determines the ON-time. Turn it clockwise to increase the ON-time.
 Increase the value of C2 for an even longer activation duration.
 The unit can be stopped at any time by pressing the STOP button.
 The START and STOP buttons can be mounted in a remote location. Make sure to use screened cable,
avoid outside interference and keep the distance between the switches and the PCB as short as possible.
 The timer is equipped with a relay output that is galvanically separated from the rest of the circuit for extra
safety. The connection example lists the function of the pins of the relay contacts.
 If the relay is used to switch important inductive loads, such as electric motors or transformers, it may be
necessary to install a snubber network across the relay contacts to avoid excessive contact wear.
 Ensure that the power supply of the circuit is sufficiently HF decoupled. Noise impulses entring
trough the power supply may start and stop the circuit unnecessarily.
13. Hook-up and use
H2579IP'2_rev1.pub
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