CN2153064Y - Test pencil - Google Patents

Abstract

The utility model discloses a test pencil used for testing whether an object has electricity. In the existing insulated pencil, a test contact, a current limiting resistor and a hand contacting electric pole are orderly in electric connecting, and the test pencil is formed and is added with a singing circuit, a circuit which is formed by that a contact type diode and piezoelectric ceramics are connected in parallel is electrically connected at the place between the current limiting resistor and the hand contact electric pole, and the insulated pencil is provided with a lighting circuit which is favorable for the contact testing operation. When the utility model is used for testing, if the tested object has the electricity, the piezoelectric ceramics can sent out the singing, and the utility model has the characteristic that the utility model is free from the light and shade influence of the operating environment.

Description

Test pencil

The utility model relates to the test pencil that a kind of test voltage exists.

In prior art, test pencil is in series by test contact, current-limiting resistance, neon tube, metal spring and hand touched electrode.Test contact is contacted with measured object, and staff contact hand touched electrode is when measured object has high voltage relative to the earth, the neon tube starter, the expression measured object is charged, still, and when working environment is bright, the neon tube starter shows not obvious, cause misjudgment easily, simultaneously, when test contact is made screwdriver when shaft-like, under darker environment, use inconvenience.

The purpose of this utility model is to provide a kind of improved test pencil, and it is charged that it can warn measured object by honeybee sound, and is applicable to use under the different light and shade environment.

The purpose of this utility model is achieved in that in the insulation handwriting, surveys formula contact, current-limiting resistance and hand touched electrode and is electrically connected successively, is electrically connected a loop that is in parallel by trigger-type diode element and piezoelectric ceramics between current-limiting resistance and hand touched electrode.In the insulation handwriting lighting circuit that is beneficial to the test contact operation is housed.During test, staff contact hand touched electrode, test contact contact measured object, charged as measured object, then the trigger-type diode element moves in circles and discharges and recharges, and forms oscillation circuit, causes the piezoelectric ceramics vibration, and it is charged to send honeybee sound caution measured object.Test contact can be made screwdriver knife bar shape, helps the lighting circuit of test contact operation in the insulation handwriting, when environment is dark, connects lighting circuit, can play a role in lighting.

Whether effect of the present utility model is to adopt honeybee to ring the caution measured object charged and increased lighting circuit, uses not influenced by the environment light and shade, can use daytime, is fit to than dark situation again.

Below in conjunction with accompanying drawing the utility model being made further detail describes:

Fig. 1 is the pencil test structure sketch.

Fig. 2 is the test pencil circuit theory diagrams.

Fig. 3 is the test pencil illuminated circuit diagram.

Referring to Fig. 1, test pencil rings circuit (4), lighting circuit (5) and hand touched electrode (6) formation by test contact (3) honeybee of insulation handwriting (1,2), insertion insulation handwriting (1).

Referring to Fig. 2, honeybee rings circuit (4) and is electrically connected successively by test contact (3), current-limiting resistance (7), trigger-type diode (8) parallel with one another and piezoelectric ceramics (9) and hand touched electrode (6), and trigger-type diode (8) also can be with mutual two voltage stabilizing diodes that dock.Conducting during for assurance current-limiting resistance (7) test, not breakdown again, its resistance value is got 450K Ω--500K Ω.

Referring to Fig. 3, lighting circuit (5) is made up of power supply (10), switch (11) and one or more light emitting diodes (12) that are connected that are in parallel, and is four light emitting diodes (12) in the present embodiment.

See Fig. 1 again, be furnished with four light holes that communicate with its internal cavity (13) insulation handwriting (1) links to each other the end face of holding with test contact (3) on, light emitting diode (12) is arranged in light hole (13) and locates.Light hole (13) gets final product leaded light, can pass honeybee again and ring.

Claims (5)

1, a kind of test pencil of test voltage existence, in insulation handwriting (1,2), test contact (3), current-limiting resistance (7) and hand touched electrode (6) are electrically connected successively, it is characterized in that between current-limiting resistance (7) and the hand touched electrode (6) being electrically connected the loop that a trigger-type diode element (8) and piezoelectric ceramics (9) are in parallel, in the insulation handwriting (1,2), the lighting circuit (5) that is beneficial to test contact (3) operation is housed.

2,, it is characterized in that trigger-type diode element (8) is trigger-type diode or two voltage stabilizing diodes that connect according to the described test pencil of claim 1.

3, according to claim 1 or 2 described test pencils, the resistance that it is characterized in that current-limiting resistance (7) is 450K Ω--500K Ω.

4,, it is characterized in that lighting circuit (5) is made up of power supply (10), switch (11) and one or more light emitting diodes that is in parallel (12) according to claim 1 or 2 described test pencils.

5, according to the described test pencil of claim 4, the handwriting (1) that it is characterized in that insulating is connected with test contact (3) has four light holes that communicate with its internal cavity (13) on the end face of end.