TNi21
07 April 2016
Page
29/38
8.1.1.3.
Selecting the cut-off voltage
The cut-off voltage should be selected:
-
According to the power supply
-
According to other devices connected to the same power supply.
If your power supply does not tolerate current feedback, fit a diode in series upstream of the ballast circuit to
protect it.
A typical cut-off voltage would be b10% and +20% of the supply voltage.
Example: For 24V DC the cut-off voltage would be 28V DC
List of components for typical operating voltages:
Rated voltage
12V
24V
32V
Cut-off voltage
14V
28V
36V
D1
SMBJ14A
SMBJ28A
SMBJ36A
R13
0R
560R 0.5W
1K 1W
R5
15K 1%
4K32 1%
3K09 1%
8.1.2. Protection for EMC
To ensure that the product is compatible with EMC standards IEC 61000-6-1, IEC 61000-6-2,
IEC 61000-6-3 and IEC 61000-6-4.
We recommend:
-
Earthing the motor with the shortest possible length of earth braid.
-
For conducted emissions with an unstabilised power supply, add a capacitor based filter and
common mode choke to the main power supply (see filter structure example below):
Component list for the above filter:
Reference
Manufacturer
Characteristics
C1 to C4
/
/
1000µF / 63V / polarised
L1 and L2
744 826 141 8
WE
1.8mH / 1
4A / 9.5mΩ
