Probe device for testing polarity of a power supply and polarity of test element with respect to the power supply

• US 5,270,638 A
• Filed: 10/08/1991
• Issued: 12/14/1993
• Est. Priority Date: 10/08/1991
• Status: Expired due to Term

• Current Assignee: Stanley Works Limited (Stanley Black & Decker, Inc.)
• Original Assignee: Mac Tools Inc (Stanley Black & Decker, Inc.)
• Inventors: Mellott, James F.
• Primary Examiner(s): Strecker, Gerard R.
• Application Number:
  US07/773,142
• Time in Patent Office: 798 Days
• Field of Search: 324/122, 324/133, 324/149, 324/509, 324/556, 324/72.5
• US Class Current: 324/133
• CPC Class Codes: G01R 19/14 Indicating direction of current; Indicating polarity of voltage

Abstract

A device for testing the polarity of both a power supply and a test element such as a circuit, wire or the like. The device is comprised of a body which contains a circuit board, a probe extending from one end of the body, and two lead wires extending from the opposite end of the body. The device will work on any DC voltage supply having a voltage from 6 volts to 24 volts.

Claims

1. A polarity testing device, comprising:

a body;

a probe extending from said body;

a first power lead extending from said body; and

a second power lead extending from said body; and

an electrical circuit contained within said body, said electrical circuit comprising a first node connected to said first lead, a second node connected to said second lead, a first LED connected to said first and second nodes, a voltage divider connected to said first and second nodes in parallel relationship to said first LED, such that when said first and second leads are connected across the terminals of a power supply, said first LED determines and indicates the polarity of the power supply, and a second LED, said second LED connected between a center tap of said voltage divider and said probe, such that when said first and second leads are connected across the terminals of a power supply and said probe contacts a test element having a potential, said second LED determines and indicates the polarity of the test element with respect to the polarity of the power supply.

2. The device of claim 1, wherein said first and second power leads comprise first and second ends, said first ends connecting to said nodes and said second ends comprising clip means.

3. The device of claim 1, wherein said body is formed of a transparent material.

4. A method for testing the polarity of a test element, comprising the steps of:

connecting a first led extending from a polarity testing device to a power source;

connecting a second lead extending from said device to a ground source; and

contacting a test element with a probe extending from said device, said device comprising an electrical circuit having a first node connected to said first lead, a second node connected to said second lead, a first LED connected to said first and second nodes, a voltage divider connected to said first and second nodes in parallel relationship to said first LED, such that when said first and second leads are connected across the terminals of a power supply, said first LED determines and indicates the polarity of the power supply, and a second LED, said second LED connected between a center tap of said voltage divider and said probe, such that when said first and second leads are connected across the terminals of a power supply and said probe contacts a test element having a potential, said second LED determines and indicates the polarity of the test element with respect to the polarity of the power supply.