Abstract: The disclosure relates to a self-sealing test probe for use in measuring the resistance between a point within an insulated wire and some external point without degrading the conductor insulation integrity. This is accomplished by utilizing a probe in the form of a hypodermic needle, the needle being electrically conductive and being coupled through appropriate circuitry to appropriate metering to determine resistance. The hypodermic is loaded with an appropriate nonelectrically conductive adhesive which, upon and during removal of the probe from the insulation, forces the adhesive through the hollow portion of the probe into the aperture in the insulation formed by the probe, thereby filling the aperture with the adhesive or sealant to fill the pinhole or void caused by the needle penetration. The amount of sealant injected can be preset or automatically metered.

Abstract: A combined voltage detector and electrical continuity checker in the form of a pencil having a needle capable of piercing electrical insulation, a pair of light emitting diodes for determining the polarity of the voltage, a third light emitting diode and associated circuitry to perform a continuity check, a flexible cable and chip which can be plugged into the pencil to perform either one of the tests in conjunction with the needle, and biasing arrangements for the light emitting diodes in order to lower their threshold of conduction.

Abstract: Mulit-mode voltage and continuity testing apparatus is disclosed for effecting a single pole phase mode of testing, and comprises first and second testing terminals, a loudspeaker, a battery energized oscillator having a control input, a control transistor, and first and second resistances. Circuitry is provided for directly connecting the battery through the emitter and collector of the control transistor to the control input of the oscillator circuit, and the first testing terminal to the base of said control transistor, whereby the testing apparatus effects a single pole phase mode in which a voltage source to be tested is connected to said first testing terminal.

Abstract: A probe for sensing the direction of flow of an injected current pulse along a conductor of a circuit under test. The probe is linked to automatic test equipment (ATE), and is triggered to inject the pulse during a test sequence at a step previously found by the ATE to establish a faulty state in the circuit so that the faulty one of several components connected to a circuit node can be identified. The probe injects an approximately triangular-waveform current pulse which has a steep rising edge and a less steep falling edge, thereby inducing a voltage level and thus permits discrimination of the direction of current flow. To detect low level current pulses in the presence of masking noise, the output of the probe is connected to the series combination of a filter, an integrator and an A/D converter. The circuit under test is set to its faulty state, and then the probe is repeatedly operated, first with the injection of the current pulses inhibited and then with current pulses being injected.

Abstract: A tuning aid for tuning musical instruments, particularly keyboard instruments, includes a sensor unit (12) which has an elongate capacitative sensor probe which is capable of extending across one octave of the instrument, and an octave switch (22) and a tone switch (20) on which are manually set the nominal octave and note of the string being measured. Amplifiers (16,24) including an AGC amplifier and controlled band-pass filters (18,26) are responsive to the octave and tone switches to select the measured tone. A divider (32) responsive to the octave switch divides the measured frequency by a power of two. A divider (38) is connected to the output of a crystal oscillator (36) to divide by a factor dependent upon the tone switch setting. The outputs of the two dividers are compared in a discriminator (34) which compares the two frequencies. A meter (50) displays the sense and magnitude of the discriminator output so as to display in terms of cents the amount by which the frequencies differ.

Abstract: An apparatus for retaining a replaceable battery comprised of a unitary structure having a chamber therein for receiving a battery and a resilient retaining means cooperating in the chamber with the battery provides a structure for easily replacing a battery. The apparatus is particularly adaptable to a programmable electrical watthour meter where a battery and programming connector in the watthour meter must be accessed through an access port in a housing of the watthour meter to replace the battery and service the watthour meter.

Abstract: A test probe for providing a releasable tensioned electrical connection to a selectable part or component of a printed circuit board by either hooking a wire or component lead with the probe end or inserting the probe end into an aperture of a test terminal.

Abstract: An electrical instrument that includes two probes extending therefrom for contacting various points of other electrical devices being checked; the instrument including a case containing an electrical circuit between the probes, the circuit including a battery, switch and indicator lamp, and one of the probes being on an extension cord that winds up around the case for storage and in which position the probes align adjacent to each other for fitting in an electric outlet socket and the like.

Abstract: An electrical testing device having a housing and a testing circuit in the housing. Electric leads extend from the housing, ending with exposed contacts mounted in prod handles. Channels are formed in the sides of the housing affording a mounting location for storage of the prod handles. Each channel can also be used as a prod holder when the device is being used. Circuitry is provided for testing continuity of the leads and for indicating the presence of a potentially harmful or dangerous voltage.

Abstract: A test device for determining the voltage and/or polarity thereof and the amount of current passing through an electric conductor has two pencil-like probes with electrical contact tips electrically connected together through a plurality of circuit elements. At least one probe has a hollow handle portion in which there is mounted a ceramic cold current limiting resistor connected to the contact tip of one of said probes, a pair of luminescent diodes connected as an antiparallel circuit to the resistor, a keying switch having a movable contact and a first and a second stationary contact. The movable switch contact is connected to the opposite end of the antiparallel diode circuit from the resistor. One stationary contact of the switch is connected to the contact tip of the second probe, while the other stationary contact is connected to the second probe tip through a battery and a protective diode.

Abstract: A miniature electrical tester provides a wide range of voltage and electrical continuity testing capabilities. A molded plastic front case has a partition which separates it into a circuit compartment and a test lead compartment. A circuit board is located in the circuit compartment, and test leads which are connected to the circuit board are stored in the test lead compartment when not in use. A molded plastic back cover has a circuit cover section which covers the circuit compartment, a test lead cover section which covers the test lead compartment, and a flexible hinge section located between the circuit and test lead cover sections. The positioning of batteries and the innerconnection of the batteries within the circuit compartment, together with the location of the remaining components of the circuit board permit the circuit board to be held securely in place by a single screw and a compression pad.

Abstract: Disclosed is a watthour meter box which allows simple disconnection of the meter and which includes a meter socket rotatably engaging the meter and a housing structure permitting the meter to be rotated from a first position where the meter is fully connected electrically to the meter socket to a second position where the meter is not fully connected electrically to the meter socket. In a preferred embodiment, the invention includes a stationary front panel having an oblong opening to admit the glass portion of the watthour meter and a movable plate behind the front wall having a similar oblong opening with a gasket reducing the opening to match substantially the perimeter of the glass wall of the meter. By releasing means securing the position of the movable plate, the meter rotates about a pivot member in the lower jaws of the socket and disengages its upper prongs from the upper jaws. Also disclosed are means securing the movable plate in the second disengaged position.

Abstract: A circuit testing device comprises(a) a casing,(b) a single probe rigidly projecting from the casing whereby the casing may be manipulated to forcibly insert the probe into an electrical power socket, and(c) a presence-of-voltage circuit in the casing and electrically connected with the probe, said circuit including a presence-of-voltage indicator, and rectifier means and amplifier means electrically connected between the probe and the indicator.The device may also advantageously include a voltage level testing circuit, and an electrical continuity testing circuit.

Abstract: The corresponding opposite end portions of wires at opposite ends of a multi-wire conductor are matched in accordance with this invention with the use of a direct current circuit tester in conjunction with a diode assembly. The diode assembly is connected to the wires at one end of the conductor and the direct current circuit tester is applied to the wires at the opposite end of the conductor according to a specified procedure to identify or match the corresponding opposite ends of the respective wires. The circuit tester comprises a pair of probes, a direct current power source, and indicator means all electrically connected and operable for indicating the presence of an electrically conductive path connected between the probes. A reversing switch is connected to the probes to permit reversing the polarity thereof, with the reversing switch including a handle portion positioned to facilitate readily actuating the reversing switch by someone using the circuit tester.

Abstract: Compact oscilloscope in which the display, an array of light emitting diodes, is integral with the probe. The array continuously is scanned column by column at a controllable rate and concurrently voltages are applied to rows selected in accordance with the amplitude of the test waveform. Light is emitted from those diodes of the array receiving coincident row and column excitation to thereby display the test waveform.

Abstract: An electrical tester adaptable for indicating the electrical condition of a conventional female electrical outlet or for indicating the electrical energization of two remote contact locations. The tester is in the form of a housing enclosing a test lamp, with a pair of male electrical prongs each connected to a different terminal of the lamp, and with the prongs fixed to a slidable block so as to be retractable into the housing when not in use. A metal test rod is slidably mounted in the housing so as to project beyond the housing in a test position, and a flexible test lead is fitted in a recess in the housing closed by a slidable door. The test rod and the test lead are each connected to a different lamp terminal.

Abstract: A pincette type multi-tester having a body portion, a minus checking bar which is rigidly attached to the bottom of said body and extending downwardly therefrom, a plus checking bar which is removably and pivotally affixed to the bottom of said body at a location spaced from said minus checking bar. The plus checking bar has a flexible helical electrical wire affixed to the top thereof which wire is electrically connected to said body at the top of the body. A flexible clip is provided located on the bottom of said body which engages the top of the plus checking bar and allows for the pivotal movement thereof as well as for complete manual disengagement therefrom.

Abstract: An electrical apparatus enclosed within a housing which contains a replaceable battery, and is provided with means for programming and/or testing by means of connectable electrical contacts with an independent instrument. The electrical apparatus is provided with a composite unit comprising a battery support and an electrical terminal connector which is arranged to cooperate with a single small access port in the apparatus housing whereby routine servicing of battery replacements, programming and/or testing, can be performed through the single port.

Abstract: An electrical testing instrument including an amplifier circuit having a pair of inputs, one comprising a probe and the other being adapted for manual engagement by the user for completing an input circuit through the body of the user. The circuit has a battery and a current-responsive indicator in its output circuit to provide a signal when current flows in the input circuit to provide a critical forward biasing of the amplifier. The battery is connected to furnish such input current when the input terminals are connected in a closed circuit having a resistance of at least approximately the resistance of the user's body. The amplifier circuit is further arranged that when the probe is contacted with a live AC power line and the manually engageable input terminal is so manually engaged, an operating indicating current will also be present in the output circuit.

Abstract: An electrical meter assembly including a plug-in meter and a meter socket, each having terminals. An adaptor modifies a terminal of the meter socket, enabling the modified and unmodified terminals thereof to engage the terminals of the meter in only one orientation of the meter relative to the meter socket.

Abstract: A probe assembly for use with an electrical voltmeter-ammeter, to adapt the meter to read electrical resistance, is provided with a pair of probe electrodes connected respectively to separate, flexible, insulated electrical conductors that are coupled to a common multi-terminal plug housing. Terminals mounted in the plug housing are arranged to cooperate with a plurality of terminals mounted on a terminal board in a meter. The probe assembly is further characterized by incorporating a fuse and a battery electrically connected in series with one of the probe electrodes and the terminal to which it is connected by a flexible conductor. A potentiometer is connected in series with one of the flexible conductors while a resistor connected between the flexible conductors to enable a meter to be adjusted for full scale deflection when it is connected to the probe assembly while the probe electrodes are in engagement with one another.

Abstract: An electric tester usable for one type of test by tapping into the battery current of a flashlight, or for an alternate type of test as a shunt across the terminals of units in a power line to determine their conductivity. The tester is a jack with a plug having terminals suitable to tap as mentioned for the first type of test. For the second type the invention provides a connector bridging the terminals to convert the jack plug into a shunt applicable as stated.

Abstract: A circuit testing device includes a casing, two probes one of which projects from the casing, a voltage level testing circuit operatively connected with one probe and incorporating simple and advantageous circuitry including transistor amplifier means and indicator means, and an electrical continuity testing circuit connected between both the probes.

Abstract: A test probe for effecting temporary electrical connection to circuit terminals of miniature integrated circuits or like elements with small inter-terminal spacings. The probe has an insulative tip having a cross-sectional dimension smaller than the space between adjacent terminals. In an axially extending groove in the tip is a stiff wire, and a mechanism is provided for controllably moving the wire out of the groove after the tip has been inserted between two terminals. When the wire moves out of the groove, it contacts one of the electric terminals and wedges the insulative tip against the adjacent terminal so as to retain the probe in place.

Abstract: A socket for a watt-hour meter is provided with a manual by-pass device to prevent interruption of power to a load when the watt-hour meter is removed from the socket. The manually operable by-pass device comprises a slider having a pair of contact bridges mounted on a body portion of the slider. The slider is mounted on an insulating base of the by-pass device for reciprocable movement. The bar is supported by contact brackets which are connected to line and load terminals of the meter socket, the slider being reciprocably movable to provide selective engagement between the contact brackets and the contact bridges when the watt-hour meter is removed from the socket.

Abstract: A circuit testing device comprisesA. multiple probes at least one of which is sized for insertion into a single electrical socket receptacle to test for the presence of voltage, and two of which are applicable to spaced conductive elements to test for electrical continuity therebetween externally of said device,B. detection means operatively connected with said probes and including indicator means to indicate the presence or absence of voltage when said one probe is inserted into said socket single receptacle, and to indicate the presence or absence of electrical continuity when said two probes are applied to said spaced conductive elements.