Device for detecting a short circuit of an H bridge

1. A device for detecting a short circuit in an H-bridge, comprising:

a printed circuit board provided with

a first connection zone ( 14 ) configured for connection to a first multipin connector connected to a power supply terminal ( 2 ) of a power supply source ( 1 ),

a power supply track ( 13 ) that connects an input point ( 10 ) of the H-bridge to the first connection zone ( 14 ), for connection to the power supply terminal ( 2 ) of the power supply source ( 1 ),

a second connection zone ( 18 ) configured for connection to a second multipin connector connected to a reference terminal ( 3 ) of the power supply source ( 1 ), and

a ground track ( 17 ) that connects an output point ( 11 ) of the H-bridge to the second connection zone ( 18 ), for connection to the reference terminal ( 3 ) of the power supply source ( 1 );

measurement means, comprising

first and second contact zones ( 141 , 142 ) of the first connection zone ( 14 ), said first and second contact zones ( 141 , 142 ) being electrically isolated from one another on the printed circuit board, said first contact zone ( 141 ) being connected to the power supply track ( 13 ) and said second contact zone ( 141 ) being connected to a first measurement track, and

third and fourth contact zones ( 181 , 182 ) of the second connection zone ( 18 ), said third and fourth contact zones ( 181 , 182 ) being electrically isolated from one another on the printed circuit board, said third contact zone ( 181 ) being connected to the ground track ( 17 ) and the fourth contact zone ( 182 ) being connected to a second measurement track ( 19 ); and

processing circuits configured to detect a short circuit in the H-bridge by comparing electrical potentials of the power supply track ( 13 ) and the first measurement track ( 15 ) on the first connection zone ( 14 ) and of the ground track ( 17 ) and the second measurement track ( 19 ) on the second connection zone ( 18 ),

wherein the first measurement track is configured to have a same potential as at the power supply terminal ( 2 ) of the power supply source ( 1 ), and the second measurement track is configured to have a same potential as the reference terminal ( 3 ) of the power supply source ( 1 ).

2. The device as claimed in claim 1 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

3. The device as claimed in claim 1 , wherein said processing circuits include a first voltage comparator ( 20 ), a second voltage comparator ( 30 ), and a third voltage comparator ( 40 ),

outputs ( 21 , 31 ) of the first and second voltage comparators ( 20 , 30 ) being in connection with a first input ( 42 ) of the third comparator ( 40 ), and a second input ( 43 ) of the third comparator connected to ground,

said first ( 20 ) and second ( 30 ) voltage comparators being configured to be:

both in a same logic state, when a difference in potential between the power supply track ( 13 ) and the first measurement track ( 15 ) is substantially equal to a difference in potential between the ground track ( 17 ) and the second measurement track ( 19 ), or else

in different logic states from each other,

and said third comparator ( 40 ) being configured to be in a low logic state when the first ( 20 ) and second ( 30 ) comparators are in said different logic states, and in a high logic state when the first ( 20 ) and second ( 30 ) comparators are in said same logic state.

4. The device as claimed in claim 1 , wherein the device is arranged such that:

when the H-bridge is shorted to the power supply terminal ( 2 ) of the power supply source ( 1 ), no current flows through the power supply track ( 13 ) and the first contact zone ( 141 ), so that an output of a voltage comparator ( 40 ) of the device is at a low potential;

when the H-bridge is shorted to ground, no current flows through the ground track ( 17 ) and the third contact zone ( 181 ), so that the output of the voltage comparator ( 40 ) is at the low potential; and

when the H-bridge is not shorted to either of the power supply terminal ( 2 ) or the ground, the output of the voltage comparator ( 40 ) is at a high potential.

5. The device as claimed in claim 1 , wherein the power supply track ( 13 ) and the first measurement track ( 15 ) are configured for connection to different respective pin points on the first connector ( 12 ).

6. The device as claimed in claim 5 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

7. The device as claimed in claim 5 , wherein the measurement circuits include, at the second connection zone ( 18 ), a first contact zone ( 181 ) and a second contact zone ( 182 ) that are electrically isolated from one another on the printed circuit board,

said first contact zone ( 181 ) and said second contact zone ( 182 ) being linked to the ground track ( 17 ) and to a second measurement track ( 19 ), respectively, and configured for connection to different pin points on the second connector ( 16 ), respectively.

8. The device as claimed in claim 7 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

9. The device as claimed in claim 7 , wherein said processing circuits include a first voltage comparator ( 20 ), a second voltage comparator ( 30 ), and a third voltage comparator ( 40 ), each one of said first, second, and third voltage comparators ( 20 , 30 , 40 ) including two input terminals and an output terminal, and each one of said first, second, and third voltage comparators configured to reversibly transition from a first logic state to a second logic state when a voltage, in terms of absolute value, between the two input terminals is higher than a predefined threshold value,

a first of the two input terminals of the first voltage comparator connected to the power supply track ( 13 ) and the ground track ( 17 ), and a second of the two input terminals of the first voltage comparator connected to the first measurement track ( 15 ) and the second measurement track ( 19 ), and

a first of the two input terminals of the second voltage comparator connected to the first measurement track ( 15 ) and the second measurement track ( 19 ), and a second of the two input terminals of the second voltage comparator connected to the power supply track ( 13 ) and the ground track ( 17 ),

said first ( 20 ) and second ( 30 ) voltage comparators being configured to be:

both in a same logic state, when a difference in potential between the power supply track ( 13 ) and the first measurement track ( 15 ) is substantially equal to a difference in potential between the ground track ( 17 ) and the second measurement track ( 19 ), or else

in different logic states from each other,

and said third comparator ( 40 ) being configured to be in a low logic state when the first ( 20 ) and second ( 30 ) comparators are in said different logic states, and in a high logic state when the first ( 20 ) and second ( 30 ) comparators are in said same logic state.

10. The device as claimed in claim 9 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

11. The device as claimed in claim 1 , wherein the ground track ( 17 ) and the second measurement track ( 19 ) are configured for connection to different respective pin points on the second connector ( 16 ).

12. The device as claimed in claim 11 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

13. The device as claimed in claim 1 , wherein said processing circuits include a first voltage comparator ( 20 ), a second voltage comparator ( 30 ), and a third voltage comparator ( 40 ), each one of said first, second, and third voltage comparators ( 20 , 30 , 40 ) including two input terminals and an output terminal, and each one of said first, second, and third voltage comparators configured to reversibly transition from a first logic state to a second logic state when a voltage, in terms of absolute value, between the two input terminals is higher than a predefined threshold value,

a first of the two input terminals of the first voltage comparator connected to the power supply track ( 13 ) and the ground track ( 17 ), and a second of the two input terminals of the first voltage comparator connected to the first measurement track ( 15 ) and the second measurement track ( 19 ), and

a first of the two input terminals of the second voltage comparator connected to the first measurement track ( 15 ) and the second measurement track ( 19 ), and a second of the two input terminals of the second voltage comparator connected to the power supply track ( 13 ) and the ground track ( 17 ),

said first ( 20 ) and second ( 30 ) voltage comparators being configured to be:

both in a same logic state, when a difference in potential between the power supply track ( 13 ) and the first measurement track ( 15 ) is substantially equal to a difference in potential between the ground track ( 17 ) and the second measurement track ( 19 ), or else

in different logic states from each other,

and said third comparator ( 40 ) being configured to be in a low logic state when the first ( 20 ) and second ( 30 ) comparators are in said different logic states, and in a high logic state when the first ( 20 ) and second ( 30 ) comparators are in said same logic state.

14. The device as claimed in claim 13 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

15. The device as claimed in claim 13 , wherein said first ( 20 ), second ( 30 ) and third ( 40 ) voltage comparators are a first, a second and a third operational amplifier, respectively, each including an output terminal ( 21 , 31 , 41 ), an inverting input terminal ( 22 , 32 , 42 ) and a non-inverting input terminal ( 23 , 33 , 43 ).

16. The device as claimed in claim 15 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).

17. The device as claimed in claim 15 , wherein two resistors ( 71 , 72 ) are arranged between the output terminal ( 21 , 31 ) and the inverting input of the first ( 20 ) and second ( 30 ) amplifiers, respectively.

18. The device as claimed in claim 17 , wherein a return resistor ( 73 ) is arranged between the H-bridge and the ground track ( 17 ).