Abstract: The approach to measuring load current in a multi-phase bridge inverter circuit connected to a multiphase load involves placing a single current sense resistor in series with the inverter circuit and power supply. The current flow through the sense resistor is sampled during a portion of the switching cycle wherein the inverter is configured to enable current flowing through the multi-phase load to flow through the sense resistor. Typically, this will occur during a portion of the switching cycle (e.g. PWM cycle) wherein the load is being actively driven. For a 120°, 3-phase, 6-step commutation sequence typically used to control a d.c. brushless servo motor, the sampled current is a time-multiplexed measure of the current flow through each load phase. The same sense resistor is also used for indicating a short circuit condition by comparing the voltage across the resistor to a reference voltage.

Abstract: During a first test phase, the device, after detecting the presence of a load, enables the nature of the load to be identified. For this, a control circuit connects the load to an AC main power system, while limiting the current in the load. The device measures several tens of samples of instantaneous values of the load voltage and current during a limited number of half-waves of an AC sine signal and determines the load impedance and the current/voltage phase shift. These characteristics, possibly with complementary parameters derived from the voltage and current measurements, enable the nature of the load to be identified. During a second test phase, the control circuit applies pulses limited in voltage to the load and detects possible short-circuit, differential or overload faults.

Abstract: An electronic circuit includes a dynamic regulator connected to a load and a dc-to-dc converter to reduce a need for bulky and expensive capacitors which would otherwise be required to suppress transients. The dynamic regulator comprises one or both of a current source circuit for actively sourcing current to the load during load current demand transients, and a current sink circuit for actively sinking current from the load during load current excess transients. The dynamic regulator preferably senses the load voltage, and tracks the load voltage. The current source circuit preferably includes a current source switch, and a current source controller for operating the current source switch responsive to the load voltage falling rapidly with respect to the tracked load voltage. In a similar fashion, the current sinking circuit may include a current sink switch, and a current sink controller for operating the current source switch responsive to the load voltage rising quickly above the tracked load voltage. In one embodiment, the load voltage tracking may be provided by a resistor-capacitor (R/C) network connected across the load. The R/C network may operate at a fast time constant for following load ripple, but at a slower time constant when sourcing or sinking current. The dynamic regulator is preferably a monolithic integrated circuit and may be either separate from or incorporated into the dc-to-dc converter.

Abstract: A load current supply circuit having a current sensing function is composed of a current mirror circuit which includes a power transistor circuit and a sense transistor circuit both connected in parallel with each other, and a current detection circuit connected to the sense transistor circuit. Load current is drawn through the power transistor while sensing current which is proportional to the load current and is much less than the load current flows through the sense transistor. The current detection circuit detects the load current based on the sensing current. A current mirror ratio has to be constant under a wide range of ambient temperature in order to secure a current sensing accuracy. To maintain the current mirror ratio at a substantially constant level, a resistance ratio of wiring resistance to transistor ON-resistance in the sense transistor circuit is made substantially equal to that in the power transistor circuit. For this purpose, compensating resistors may be disposed at both sides of the sense transistor in the sense transistor circuit.

Abstract: A load transient compensator and method of operating the load transient compensator for reducing the transient response time to a load capable of operating at either of several consumption levels when the load changes its power consumption level. The load transient compensator has a comparator having an output connected to an input of an upper driver and of a lower driver with the output of each of the driver being connected to a gate of a power transistor. When the load is in sleep mode and is about to start being accessed, the upper driver is turned on to turn on its associated transistor to supply additional current to the load, regulated by the comparison circuit. When the load is in the power up mode and it is about to stop being accessed, the lower driver is turned on to turn on its associated transistor to drain current supplied to the load by a supply, regulated by the comparison circuit. This allows a quicker response to the large changes in current required by the load when the load is changing its level of power consumption without greatly increasing the cost of the system containing the load and without compromising the stability of the system.

Abstract: An applied-voltage-based current measuring apparatus in which an operational amplifier is supplied at its non-inverting input terminal with a predetermined voltage and at its inverting input terminal with a voltage to be applied to a load. A current measuring resistor is connected between the output terminal of the operational amplifier and the load and a voltage which is created across the current measuring resistor is measured to thereby measure a current flow to the load in the state of being supplied with a predetermined voltage and in which a plurality of current measuring resistors are connected in series in correspondence to current measuring ranges. Switching elements for current bypass use, each of which turns ON when the voltage created across the corresponding current measuring resistor reaches a predetermined value, are connected in parallel to the current measuring resistors. Automatically carrying out sequential measurements of voltages created at respective ends of the current measuring resistors. The measured results are subjected to subtraction processing to compute voltages which are developed across the current measuring resistors. The apparatus selects from the computed results an optimum value contained in any one of the measuring ranges, thereby specifying the current flowing to the load.

Abstract: The ignition coil driver module of the present invention includes a control integrated circuit, formed of a low voltage semiconductor material, and a high current load driver integrated circuit, formed of a high voltage integrated circuit, housed within a common package. The high current load driver integrated circuit is responsive to a low voltage drive signal provided by the control integrated circuit to permit a load current to flow unrestricted through the load driver integrated circuit and an inductive load connected thereto. The control integrated circuit includes a sense resistor which receives the load current from the high current load driver integrated circuit, converts this current to a sense voltage, compares the sense voltage to a reference voltage generated within the control integrated circuit, and forces the low voltage drive signal to drop to a level which will limit the load current to a predetermined current value.

Abstract: In this paper we describe a CMOS differential active load and show how it can be used to create various useful structures. Tunable current gain stages and current squaring circuits are discussed. Their connection to a differential pair-based transconductor results in broad-range tunable transconductor structures suitable for adaptive continuous-time filtering applications and a four-quadrant voltage multiplier.

Abstract: A circuit to control the supply of a reactive load, for supplying variable quantities of energy to the load in a predetermined manner is included in a system. The system also includes reactive components which are connected to the load by way of a controllable electronic switch and which form a resonant circuit with the load when the electronic switch is closed. Further, the system includes a circuit for activating the electronic switch, and a control unit which coordinates the operation of the controlled supply circuit and of the activation circuit in accordance with a predetermined program. The system enables the load to be driven with a particularly low power dissipated.

Abstract: A current sensing circuit including a shunt resistor coupled, at one end, to the low-side transistor of a half bridge circuit and, at its other end, to a load. The voltage sensed across the shunt resistor is proportional to the current delivered to the load. A level shifting circuit is provided to transpose the sensed voltage to a low voltage signal which can be fed back to control commutation of the transistors in the half bridge circuit.

Abstract: A composite load circuit for use within another circuit includes at least one amplifying transistor. The composite load circuit includes first and second transistors connected in parallel. Each load transistor has a gate that receives a common control voltage. Each load transistor also has a different turn-on threshold voltage. A resistor, connected in parallel with the load transistors, limits an effective impedance of the load transistors.

Abstract: A power supply for supplying power from a direct current (DC) source (116) to a load (104). A load control circuit (102) connected to the load and connected to the DC source regulates a voltage applied to the load. An inductive circuit (100) connected to the load control circuit supplies power to the load. A switching circuit is connected between the DC source and the inductive circuit and responds to the inductive circuit. The inductive circuit supplies power to the switching circuit and controls the switching circuit to selectively connect the DC source to the inductive circuit.

Abstract: A resistor network having a precise ratio of resistances of all resistors within the network while having a compact layout to minimize area is described. The integrated circuit resistor network has a plurality of unit resistors. Each unit resistor is composed of a thin film resistive material. The area of the thin film resistive material to form the unit resistor is a median value of the resistor elements to be formed into said integrated circuit resistor network. Each unit resistor has a contact means to connect to the plurality of unit resistors. A plurality of metal interconnection segments will connect to the contact means to form said integrated circuit resistor network. A plurality of metal conductive segments are connected to a metal interconnection segments and to external circuitry to connect the external circuitry to the integrated circuit resistor network.

Abstract: Each load circuit (4a,4b) contains a source of voltage (41) in series with a resistive load (42) and a load switch (43). The loads are connected and disconnected independently by the load switches. A test section (3) compares the aggregate load current with a reference value which is a function of the load switch position. The switches are operated by an address section (2) receiving information via data lines (12a,12b) from a control section (1). If the aggregate current exceeds an upper limit or falls short of a lower limit, a corresponding warning is given by the test section.

Abstract: A DC-to-DC converter includes an inductor and a diode that are connected in series between a positive supply terminal and a positive output terminal, and a storage capacitor connected between the positive output terminal and a negative terminal. The DC-to-DC converter further includes a first switch including a lateral MOS transistor connected between the anode of the diode and the negative terminal, a second switch including a vertical MOS transistor connected in parallel to the first switch, a first active load circuit connected between the positive and negative supply terminals and designed to control the first switch, a second active load circuit connected between the positive output terminal and the negative terminal and designed to control the second switch, and an oscillator providing a periodic signal for controlling the active loads.

Abstract: A temperature set point circuit employs a pair of bipolar transistors (Q6, Q9) operated at unequal current densities, with the difference between the transistors' base-emitter voltages appearing across a trim resistor (R6) connecting their emitters. A pair of trim resistors (R3, RA) one of which may be external to an integrated circuit embodiment of the set point circuit, form a resistor divider with the inter-base resistor and are selected to produce a desired temperature trip-point.

Abstract: A heating resistor type air flow meter for measuring the amount of air flow which passes through an intake pipe for an internal combustion engine The air flow meter has a constant-temperature control circuit for detecting air flow, which has a bridge circuit including a heating resistor and a temperature-sensitive resistor each provided in the intake pipe, and a power amplifier circuit for amplifying a signal from the constant-temperature control circuit to generate an air flow signal The power amplifier circuit has a plurality of amplification resistors which determine a mu-factor for the amplifier to correct the amount of air flow with respect to variation of temperature At least an amplification resistor has a temperature coefficient different form that of the other amplification resistor, to compensate variation of the mu-factor of the power amplifier circuit

Abstract: A detection circuit includes a current mirror circuit that produces electric currents at first and second output terminals in response to a current supplied to its input terminal. A first active load is connected to the first output terminal and a second active load is connected to the second output terminal and an external output terminal. A control circuit controls the potential of the control electrode of the second active load according to the voltage or the current at the first output terminal. The control circuit can include a capacitive device that determines the voltage at the control electrodes of the active loads according to the peak value of current supplied to the current mirror circuit input terminal.

Abstract: PROBLEM TO BE SOLVED: To prevent the compensating ratio of higher harmonic from being lowered even when the fundamental wave of load current is unbalanced. SOLUTION: This device is provided with a load current fundamental wave anti-phase component arithmetic circuit which consists of an anti-phase three-phase two-phase conversion circuit 20 which converts an anti-phase component of load current detection value from a three-phase into a two-phase, a 1st anti-phase component arithmetic circuit 21 which calculates an anti-phase effective component and anti-phase ineffective component of load current from the output signal and an output signal of a phase-locked loop, a 1st anti-phase detection lowpass filter 22 which takes out a direct current component of the anti-phase effective component signal, a 2nd anti-phase detection lowpass filter 23 which takes out a direct current component of the anti-phase ineffective component signal, a 2nd anti-phase component arithmetic circuit 24 which operates an anti-phase fundamental wave component of the load current in two-phase from an output signal of each-phase detection lowpass filter and an output signal of the phase-locked loop and an anti-phase component two-phase three- phase conversion circuit 25 which converts the output signal form two-phase into three-phase. An output signal of a fundamental wave adder 26 which adds each output signal of a two- phase three-phase conversion circuit 15 and the anti-phase component two-phase three-phase conversion circuit is inputted as a subtraction element of a 1st a subtracted 16.

Abstract: The resistor is designed in the form of a column and has a cylindrical resistor body which is arranged between two planar electrodes, aligned parallel, and is made of a ceramic material. The resistor is preferably a varistor on a metal-oxide base, and is then used as a voltage-limiting element in an overvoltage suppressor. The strength of the ceramic material and the length of the resistor are chosen to be as great as possible. However, the length of the resistor is at most sufficiently large that damage to the ceramic resistor body caused by thermally produced pressure waves is avoided when the resistor is loaded in an electrical field of given magnitude with at least one highly energetic current pulse of defined amplitude, form and duration.

Abstract: An active input circuit module includes a plurality of active input circuits disposed on a circuit board each circuit having an input and a return. Each active input circuit further has a constant current source having a current source input and a constant current output coupled through a current limiting resistor to an opto-coupler input and the return. A shunt resistor is coupled in parallel with the opto-coupler input.

Abstract: A complementary class AB current mirror circuit with a constant current gain which, when driven by a transconductance amplifier, provides a constant overall voltage gain over a wide range of output current. Such current mirror circuit includes cross-coupled pairs of current mirror circuits, both of which are driven by a common reference current and each of which selectively receives a respective portion of the input signal current. The upper pair of current mirror circuits includes: an input current mirror circuit which generates a drive current for the output stage of the lower pair of current mirror circuits; and an output current mirror circuit which generates the source, or "push," portion of the output signal current. The lower pair of current mirror circuits includes: an input current mirror circuit which generates a drive current for the output stage of the upper pair of current mirror circuits; and an output current mirror circuit which generates the sink, or "pull," portion of the output signal current.

Abstract: An electric circuit for determining the load current of a clocked load having at least one inductive component and being assigned a free-wheeling circuit has a shunt whose voltage drop is used to determine the current. The shunt is arranged in the free-wheeling circuit to determine the free-wheeling current which is used as a measure for determining the load current (motor current). Furthermore, according to another embodiments the shunt is in series with the load and the free-wheeling circuit is arranged in parallel to the series connection of load and shunt.

Abstract: A circuit for detecting the load current (IL) flowing through a load, the latter being switched by means of an electronic power switch ie enhancement type n-channel MOSFET, is arranged with a current branching circuit allocated to the power switch (1) which branches or taps part of the current flowing through the power switch (1) and the load (2) on to a reference circuit consisting of a reference switch (10) and a reference resistance (11), in such a way that the value of the voltage (Ui) dropped across the reference resistance (11) clearly corresp to the value of load current flowing through the load (2)

Abstract: In a regulated power supply circuit which includes a differential amplifier circuit and a current output circuit which receives the output from the differential amplifier circuit, wherein the current output circuit comprises a drive stage transistor which operates upon receipt of an output from the differential amplifier circuit at an input terminal thereof, a current output stage of a MOSFET which is driven by the drive stage transistor and a load resistor for the drive stage transistor connected to the output side thereof, and the load resistor and the drive stage transistor are provided between a power source line and a ground line and the MOSFET is driven by an output taken out via the load resistor.

Abstract: A circuit for protecting a laser indicator is disclosed in which a current amplifying circuit composed of two transistors drives a laser light emitting diode (LED) to generate a laser light. A base of one of the two transistors connects with a protective resistor and a variable resistor. The variable resistor is used to control the magnitude of a base current of the transistor and the protective resistor is used to prevent an overrating current. A diode is further coupled to a positive power input terminal of the current amplifying circuit to prevent the circuit for protecting a laser indicator from being damaged due to being reversely connected the polarities of the power source. Through a design of such a circuit, a stable laser light-spot is achieved and the components in the circuit will not be damaged.

Abstract: The circuit connects the supply network to the load (10) and contains a low pass filter (12) which achieves a continuous input current, and a coil (14) in series with or part of the load. A first a.c. switch (16) is in parallel with the load and coil, and a second a.c. switch (32) is driven at a frequency higher than the supply frequency and connected in series with the load. A controller (34) detects the a.c. or d.c. load current directly or indirectly, has an input for a desired a.c. or d.c. load current and drives the second switch with a suitable switching frequency and duty cycle to achieve the desired load current.

Abstract: An IC having a built-in over voltage protecting circuit comprising: a first operating circuit having a first resistor connected to a terminal the voltage at which varies depending on a voltage at a first terminal; a second operating circuit; a protecting circuit having a second resistor, which receives a detection signal via the second resistor and controls the operation of the second operating circuit therewith to thereby protect the operation of the second operating circuit, wherein the first resistor and the second resistor are formed adjacently in a device-isolated common resistor forming land as regions having different conductivity type from that of the resistor forming land, the potential of the resistor forming land is set at a predetermined voltage which is different from the voltage at the first terminal, and the detection signal is generated, when a transistor which is composed by the first resistor, the second resistor and the resistor forming land is turned ON in response to a variation of the voltage at the first terminal by a value more than a predetermined value.

Abstract: PROBLEM TO BE SOLVED: To set a threshold value at the reference of signal input by connecting active loads to a pair of output ends of a current mirror circuit respectively, and controlling the active load of the other terminal connecting an outside output terminal in response to voltage value of one terminal. SOLUTION: A current mirror circuit 2 connects an input terminal Sin to a signal supply means, couples an output terminal (a) to active load 6 and connects another output terminal (b) to the other active load 4 and an outside output terminal Sout respectively. A control circuit 3 controls current flowing in the load 4 in response to voltage of the terminal (b). A ratio of current supply ability of the loads 4, 6 is set at a previously proper ratio. When signal current (is) is input to the terminal Sin, current of (is)×N is flowed to the terminals (a), (b) of the circuit 2 in response thereto (N is determined by the constituent element of the circuit 2). The control circuit 3 is connected to the terminal (a), when the terminal (a) is prescribed voltage, the control electrode of the loads 4, 6 is controlled to flow current, and the current of is ×N/M is flowed in the terminal (b). Thus, in the terminal (b) the value is/M is made a threshold value to change over the output.