SWITCH TESTING CIRCUIT

• US 20110254556A1
• Filed: 06/21/2010
• Published: 10/20/2011
• Est. Priority Date: 04/19/2010
• Status: Active Grant

• Current Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Original Assignee: Hong Fu Jin Precision Industry (Shenzhen) Co., Ltd. (Hon Hai Precision Industry Co., Ltd.), Hon Hai Precision Industry Co., Ltd.
• Inventors: SHI, YAN
• Granted Patent: US 8,410,782 B2
• Time in Patent Office: Days
• US Class Current: 324/416
• CPC Class Codes: G01R 31/3277 of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults

Abstract

A switch testing circuit is configured for testing a switch. The switch testing circuit includes a switch element, a first light emitting diode, and a control chip. The first light emitting diode, the switch element, and the switch are connected in series. The first light emitting diode is configured for indicating connection condition between the switch and the switch testing circuit. The control chip is configured for acquiring a voltage from one terminal of the switch element and comparing the acquired voltage with a comparison voltage to judge whether the switch is qualified or disqualified according to the comparison result.

Claims

1. A switch testing circuit configured for testing a switch, comprising:

a switch element comprising a first terminal, a second terminal, and a control terminal for controlling the connection between the first terminal and the second terminal;

one terminal of the switch is connected to the second terminal of the switch element, and another terminal is grounded;

a first light emitting diode comprising a cathode coupled to the first terminal of the switch element and an anode coupled to a power source;

the first light emitting diode configured for indicating the connection condition between the switch and the switch testing circuit; and

a control chip comprising a signal terminal coupled to the control terminal of the switch element and a detecting terminal coupled to the first terminal or the second terminal of the switch element;

the control chip configured for acquiring a voltage of the first terminal of the switch element and comparing the acquired voltage with a comparison voltage to judge whether the switch is qualified or disqualified according to the comparison result.

2. The switch testing circuit in claim 1, further comprising a second light emitting diode, wherein the second light emitting diode comprises an anode coupled to the control terminal of the switch element and a cathode being grounded;

the second light emitting diode configured to indicate when the signal outputs from the signal terminal of the control chip.

3. The switch testing circuit in claim 1, further comprising a third light emitting diode, wherein the third light emitting diode comprising a cathode coupled to the second terminal of the switch element and an anode coupled to the power source;

the third light emitting diode cooperating with the first light emitting diode to indicate the working status of the switch testing circuit.

4. The switch testing circuit in claim 1, wherein the switch element is an n-channel metal oxide semiconductor (NMOS) transistor, the first terminal served as a drain, the second terminal served as a source, and the control terminal served as a gate.

5. The switch testing circuit in claim 1, wherein the comparison voltage defines a tolerance of acceptable range ±

5%.

6. The switch testing circuit in claim 1, wherein the control chip further comprises an alarm terminal coupled to a buzzer.

7. A switch testing circuit configured for testing a switch, comprising:

a switch element comprising a control terminal for controlling the connection thereof;

a first light emitting diode and the switch are connected in series to the switch element, and form a loop; and

a control chip comprising a signal terminal coupled to the control terminal of the switch element and a detecting terminal coupled to the loop;

the control chip configured for acquiring a voltage of the loop and comparing the acquired voltage with a comparison voltage to judge whether the switch is qualified or disqualified according to the comparison result.