iC-GE
PWM RELAY/SOLENOID DRIVER
Rev A2, Page 11/14
Application example with four relays of equal acceleration
REL# Relay type
REL1 REL2 REL3 REL4
6000 3000 1500 3000
0.2 0.28 0.4 0.4 mm
N
d
No. of turns
Wire diameter
VBLn Nominal coil supply voltage
24
18
30
12
9
15
6
4.5
7.5
6
4.5
7.5
V
V
V
VBLmin Minimum required supply voltage 75% of VBLn
VBLmax Maximum allowed supply voltage VBLn + 25%
ISWn Nominal coil current
208 416 832 416 mA
Ri
Coil resistance at room temperature
115.4 28.8 7.2 14.4
155 38.8 9.7 19.4
Ω
Ω
Rimax Elevated coil resistance at 80 °C
PvLn
Imin
Power dissipation in the coil VBLn2 / Ri
Table 4: Manufacturer data
5
5
5
2.5
W
Energising current VBLmin / RImax, for sure switching of the realy 116 232 464 232 mA
at high temperature and low power supply
RACT Calculation: RACT = K1min / Imin = 4500 / Imin, the selected 38.8 19.4 9.7 19.4 kΩ
resistor must be smaller then the calculated value
ISWmax Maximum current is ISWmax = K1max / RACT = 5500 / RACT
142 284 567 284 mA
VBLact Maximum voltage at coil Rimax ∗ ISWmax
22.0 11.0 5.5
5.5
0.2
V
V
Vs
Saturation voltage Characteristics No. 101 and No. 102 interpo- 0.1
0.2
0.4
lated, Vs()lo ∗ ISWmax / 1000 mA
VBmin Minimum supply voltage at iC-GE VBLact + Vs
VBmax Maximum supply voltage at iC-GE
22.1 11.2
10
36
10
36
V
V
36
36
Pv
Power dissipation at PWM Vs / VBLact
0.5
1.8
7.3
3.6
%
IVB
Average current in VB for PWM at 24 V VB
131 133 139
68 mA
ISWmax ∗ VBLact / 24 V ∗ (1 + Pv)
PvL
Power dissipation in the coil Rimax ∗ ISWmax2
3.12 3.12 3.12 1.56
W
W
PvLhold Power dissipation at reduced hold current IHOLD of e.g. 2/3 ∗ IACT 1.39 1.39 1.39 0.7
Table 5: iC-GE application
REL1 would be a standard 24 V relay. It could only be
used with iC-GE, if operation at 22.1 V can be guaran-
teed.
REL2 and REL3 are 6/12 V standard relays and thus
optimal usable with iC-GE at a 24 V supply voltage.
REL4 is optimised for low power dissipation, since the
coils has twice the number of turns than REL3 and a
√
2 wider diameter than REL2. Thus the power dissi-
pation in the coil is halved.
By means of the optimised power control e.g. with a
permanently-on 24 V mains-insulation relay of photo-
voltaic or heating systems up to
Figure 14: Energy savings
(5 W − 0.7 W) ∗ 24 h ∗ 365 days = 37.7 kWh
may be saved per year.
ICHAUS [ IC-HAUS GMBH ]
