Circuit arrangement for high-speed switching of inductive loads
A circuit arrangement for switching an inductive load ( 12, 12 a-d ) with connections to a power supply source ( 11, 11′, 11 ″) by means of which an exciter voltage can be applied to the inductive load ( 12, 12 a-d ) in a switched-on state is described, comprising switching means by means of which, depending on a control signal, a power circuit comprising the inductive load ( 12, 12 a-d ) and the power supply source connections, can be closed when switched from the switched-off to the switched-on state and opened when switched from the switched-on to the switched-off state, furthermore comprising a first diode ( 15, 15 a-d , 15 a′-c ′, 15 a″-c ″) arranged in parallel with the inductive load ( 12, 12 a-d ) and so as to block in the switched-on state. This present invention is characterized in that an additional commutation inductance ( 18 ) is provided which is arranged in parallel with the inductive load ( 12, 12 a-d ) and in series with the first diode ( 15, 15 a-d , 15 a′-c ′, 15 a″-c ″).
1. A circuit arrangement for switching an inductive load, comprising:
connections to a power supply source for applying an exciter voltage to the inductive load in a switched-on state,
switching means for opening and closing, depending on a control signal, a power circuit comprising the inductive load and the power supply source connections, wherein the circuit is closed when switched from the switched-off to the switched-on state and opened when switched from the switched-on to the switched-off state,
a first diode connected in parallel with the inductive load and arranged to block in the switched-on state, and
an additional commutation inductance arranged in parallel with the inductive load and in series with the first diode.
2. A circuit arrangement in accordance with claim 1 , further comprising at least one other inductive loads connected in series with an individual associated switching means and an individual associated diode, and a commutation inductance connected in parallel with the inductive load and in series with the diode.
3. A circuit arrangement in accordance with claim 1 , further comprising a second diode connected in parallel with the commutation inductance and arranged to block in the switched-on state.
4. A circuit arrangement in accordance with claim 1 , wherein the commutation inductance or the network comprising a commutation inductance and second diode is provided on the ground side of the switching means.
5. A circuit arrangement in accordance with claim 1 , wherein the commutation inductance or the network comprising a commutation inductance and a second diode is provided on the supply voltage-side of the switching means.
6. A circuit arrangement in accordance with claim 1 , wherein the inductive loads are magnetic injection valves in a motor vehicle.
7. A circuit arrangement in accordance with claim 1 , wherein the switching means comprise a switching transistor to which a control power source can apply a control voltage as a control signal.
8. A circuit arrangement in accordance with claim 1 , wherein the switching transistor is a self-blocking MOS-FET.
9. A circuit arrangement in accordance with claim 1 , wherein several switching transistors are provided controlled by a joint control power source whose signal is distributed to several switching transistors via demultiplexing.
10. A method for switching an inductive load, comprising:
providing an exciter voltage that can be applied to the inductive load in a switched-on state,
switching, depending on a control signal, a power circuit comprising the inductive load and power supply source connections into either a switched-on state or a switched-off state,
connecting a first diode in parallel with the inductive load and arranging it to block in the switched-on state, and
providing an additional commutation inductance arranged in parallel with the inductive load and in series with the first diode.
11. A circuit arrangement in accordance with claim 10 , wherein the inductive loads are magnetic injection valves in a motor vehicle.
12. A method in accordance with claim 10 , further providing several inductive loads that are connected in series with individual associated switching means and individual associated diodes, and providing a commutation inductance which is connected in parallel with the inductive loads and in series with the diodes that are connected with each other in parallel.
13. A method in accordance with claim 10 , further providing a second diode connected in parallel with the commutation inductance and arranged to block in the switched-on state.
14. A method in accordance with claim 10 , providing the commutation inductance or a network comprising a commutation inductance and a second diode on the ground side of the switching means.
15. A method in accordance with claim 10 , providing the commutation inductance or a network comprising a commutation inductance and a second diode on the supply voltage-side of the switching means.
16. A method in accordance with claim 10 , wherein for switching several inductive loads, providing several switching transistors controlled by a joint control power source whose signal is distributed to several switching transistors via demultiplexing.
17. A method in accordance with claim 10 , wherein the switching means comprises a switching transistor to which a control power source can apply a control voltage as a control signal.
18. A method in accordance with claim 10 , wherein the switching transistor is a self-blocking MOS-FET.
19. A circuit arrangement for switching an inductive load, said arrangement comprising:
power supply connections to supply an exciter voltage to the load in a switched-on state,
a switch to open and close, depending upon a control signal, a power circuit comprising the load and power supply connections, wherein the circuit is closed when switched from a switched-off state to the switched-on state and opened when switched from the switched-on state to the switched-off state,
a first diode connected in parallel with the load and arranged to block in the switched-on state,
a first commutation inductance arranged in parallel with the load and in series with the first diode, and
second and third commutation inductances or two networks comprising a commutation inductance and a second diode, one arranged on the ground side and the other on the supply voltage-side of the switch.
20. A method for switching an inductive load, comprising:
applying an exciter voltage to the load in a switched-on state,
switching, depending on a control signal, a power circuit comprising the load and power supply connections into either a switched-on state or a switched-off state,
connecting a first diode in parallel with the inductive load and arranging it to block in the switched-on state,
providing a first commutation inductance and arranging it in parallel with the load and in series with the first diode, and
providing two additional commutation inductances or two networks comprising a commutation inductance and a second diode, wherein one is arranged on the ground side and the other is arranged on the supply-voltage side of the switch.