An instrument for performing electrical tests includes a housing adapted to be held in the hand. A conductive probe and a two-conductor power cable adapted to be connected to a vehicle battery protrude from the housing. Red and green light emitting diodes (LED's) mounted in the housing are operatively interconnected with the probe and power cable through circuitry which causes the red LED to glow when the probe contacts a positive voltage, and the green LED to glow when the probe contacts a low voltage, ground, or a negative voltage. Continuity testing may be performed by contacting the probe against one terminal of a device to be tested, and contacting the other terminal of the device to ground or to an auxiliary test lead extending from the housing, causing the green LED to glow. The instrument includes a momentary contact switch that permits the probe to be energized by internal connection to the positive or ground input terminal. Actuating the switch momentarily to energize the probe with a positive voltage causes the green LED to cease glowing and the red LED to glow if the test probe is in contact with a low resistance device, rather than directly to ground, thus providing means to determine whether ground or the supply terminal of a high-current load device has been probed.

Electrical tester with electrical energizable test probe

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.

Miniature electrical voltage and continuity tester with circuit compartment and test lead compartment casing

A semiconductor device comprises an insulating substrate such as a film carrier having wiring patterns formed thereon, lead electrodes connected to the wiring patterns, and a semiconductor chip bonded to the lead electrodes. The surface of the lead electrodes, to which the semiconductor chip is bonded, is smooth as compared with that of the wiring patterns, thereby ensuring accurate operation of the semiconductor device.

Lead electrode structure for a semiconductor chip carried on a flexible carrier

A multi-function tester (10) for testing electrical continuity and detecting the presence of various types of voltages comprises a bistable flip flop (14) having set and reset input terminals (2, 6) which are driven by voltage changes thereat to change the level of voltage appearing at an output terminal (3), with the set input terminal being coupled to a voltage source (12) through a set resistor (30) and being coupled to a common terminal (26) through a TMOS FET switch (16). An LED (32) is connected between the flip flop output terminal and the common terminal. A storage switch (18) couples and decouples the set and reset terminals. A voltage probe (20) coupled to the DC voltage source, a common probe (22), coupled to the common terminal, and a switch probe (24), coupled to a switching terminal (38) of the TMOS FET are used to place voltage signals on the switching terminal, both directly and through other circuits, for changing a switching impedance of the TMOS FET and thereby changing the voltage at the set and reset input terminals for changing the state of the flip flop and thereby activating and deactivating the LED.

Multi-function tester

Hermetically sealed unit containing an integrated circuit metal oxide semi-conductor chip, wherein a single layer gold-silver alloy serves both to secure the chip within the unit and to form a proper junction with the aluminum alloy conductor connected to a circuit element in said chip. A sufficient proportion of silver is included in the gold-silver alloy whereby said junction retains requisite operational characteristics of bond strength and low resistivity when said unit is subjected to heat for providing a hermetic seal therefor.

Method of assembling a hermetically sealed semiconductor unit

A portable test instrument for testing electrical continuity, and diode polarity, AC and DC voltage amplitudes and DC voltage polarity. An electronic switch device has main electrodes connected in an indicating circuit with an electrical supply, a light-emitting diode and a current-limiting resistor. A double pole, double throw switch is manually switchable between continuity and voltage test positions, and with four resistors defines an input circuit interposed between the control electrode of the electronic switch device and probes connectible to a circuit or the like to be tested. In both the voltage and continuity test modes of the instrument, the light-emitting diode is energized only by current from the electrical supply within the indicating circuit. Though proper circuit operation is obtained by manual manipulation of the mode switch between its voltage and continuity positions, the light-emitting diode is automatically protected from damage should the test probes engage a voltage circuit (within the operating voltage range of the instrument) while the instrument is in continuity mode.

Phillip M. Stewart

Papers

Voltage and continuity checker

Rotating air cylinder utilizing air as air seal