Circuit for diverting surges and transient impulses
View Patent ↗A circuit for attenuating a surge is disclosed that might include a conductor for receiving the surge, a capacitor, positioned along the conductor, for blocking the surge, and a gas tube having a first end coupled to the conductor and a second end coupled to a ground. The circuit might also include a transformer having a first wire and a second wire, the transformer being coupled to the conductor, a resistor coupled to the first and second wires of the transformer, a varistor coupled to the first wire of the transformer, and a diode coupled to the second wire of the transformer.
1. A circuit for attenuating a surge comprising:
an input conductor for receiving a signal and a surge induced overcurrent;
an output conductor for receiving the signal;
a capacitor, connected between the input and output conductors, for blocking the surge;
a gas tube having a first end connected to the input conductor and a second end connected to a ground;
a transformer in parallel with the capacitor, the transformer having a core and first and second wires wound around the core, the first wire of the transformer connected to the input conductor, the second wire of the transformer connected to the output conductor and the core saturating when the surge induced overcurrent reaches the first wire; and
a resistor connecting the first and second wires of the transformer.
2. The circuit of claim 1 , further comprising a diode connected to the second wire for diverting a first portion of the surge induced current to ground.
3. The circuit of claim 2 , further comprising a varistor connected to the first wire for diverting a second portion of the surge induced current to ground.
4. The circuit of claim 3 , wherein the varistor is a metal oxide varistor and the diode is a transient voltage surge diode.
5. The circuit of claim 1 , wherein the core is a ferrite toroid core.
6. A surge suppression circuit having an input conductor for coupling to a signal line and an output conductor for coupling to equipment to be protected, the circuit comprising:
a capacitor having a first conductor connected to the input conductor and a second conductor connected to the output conductor; and
a transformer having a primary winding connected to the first conductor of the capacitor and a secondary winding connected to the second conductor of the capacitor.
7. The circuit of claim 6 , wherein the transformer has a core that has a toroid configuration and is made of a ferrite material.
8. The circuit of claim 7 , wherein the first and second conductors are wrapped around the core.
9. The circuit of claim 6 , wherein:
the input conductor is configured to receive a direct current, a low frequency signal, a high-frequency signal and a surge;
the capacitor is configured to pass the high-frequency signal and block the direct current, the low-frequency signal and the surge; and
the transformer is configured to pass the direct current and to couple the low-frequency signal to the output conductor.
10. The circuit of claim 6 , further comprising a gas tube, coupled to the input conductor, for diverting a portion of a surge to ground.
11. The circuit of claim 6 , further comprising a metal oxide varistor, coupled to the transformer, for diverting a portion of a surge to ground.
12. The circuit of claim 6 , further comprising a diode, coupled to the transformer, for diverting a portion of a surge to a ground.
13. The circuit of claim 12 , further comprising a resistor, coupled to the transformer, for protecting the diode.
14. A circuit for attenuating transient impulses comprising:
an input port configured to receive a signal and a transient impulse having a leading portion and a trailing portion;
a gas tube directly connected to the input port and configured to divert the trailing portion of the transient impulse to ground;
a capacitor directly connected to the input port and configured to pass the signal and block the leading portion of the transient impulse;
a transformer directly connected to the input port and configured to pass the signal and the leading portion of the transient impulse; and
a varistor directly connected to the transformer and configured to divert a part of the leading portion of the transient impulse to ground.
15. The circuit of claim 14 , further comprising a diode, coupled to the transformer, for diverting a part of the leading portion of the transient impulse to ground.
16. The circuit of claim 15 , further comprising a resistor, coupled to the transformer, for protecting the diode.
17. The circuit of claim 15 , wherein the diode is turned on before the varistor, which is turned on before the gas tube.
18. The circuit of claim 14 , wherein the transformer has a core and first and second wire wound around the core.
19. The circuit of claim 18 , wherein the core has a toroid configuration and is made of a ferrite material.
20. The circuit of claim 14 , wherein the varistor is a metal oxide varistor.