Abstract: A circuit arrangement for providing a frequency for a computer circuit is suggested in which, in adition to a quartz oscillator, an additional oscillator which quickly begins to oscillate is provided. To ensure a quick operation of the computer circuit when switching on the computer circuit or after voltage dips, the oscillator which quickly begins to oscillate is first connected with the computer circuit when voltage is applied, so that the resetting processes can proceed very quickly. If the quartz oscillator has begun to oscillate and has reached a stable operating state, a switching is effected from the oscillator which quickly begins to oscillate to the quartz oscillator which takes over from the latter to continue providing a frequency for the computer circuit. The circuit arrangement can also contain a comparator whose inputs are connected to the respective oscillators and which compares the oscillator frequencies of the output signals from both oscillators.

Abstract: In a control device (14) for fuel injection and/or spark ignition in an internal combustion engine, a first datablock (16) is programmed for operation in accordance with engine operating parameters (BM, P, L, n, T) but without lambda control when the engine is cold and a second datablock (18) is programmed for operation with lambda control when the engine is warm. A switching logic (26) switches in the first datablock (16) when the engine is started below a lower threshold (T.sub.1) and switches over to the second datablock (18) when the temperature rises above a higher threshold (T.sub.2).

Abstract: A control apparatus with connecting terminals which are in part connected to serve a plurality of functions. The control apparatus has at least one memory and can be especially for a control apparatus of an electronic internal combustion engine control wherein an additional voltage source for the memory is provided via at least one output terminal accommodating at least one function.

Abstract: An apparatus for resetting computing devices, particularly devices for fuel proportioning or fuel injection, for adjusting ignition timing, and the like, which are controlled by microprocessors, includes a resetting circuit to evaluate the change in the switching state of the ignition lock switch of the motor vehicle when restarted. The evaluation is effected independently of the supply voltage still at the computing device due to a self-sustaining circuit, by means of an integrated differentiation and the differentiation voltage is fed to a comparator at whose output the reset pulse is formed.

Abstract: The invention is directed to a method for compensating for the tank venting error in a learning fuel metering system metering the required fuel quantity to an internal combustion engine. The method includes carrying out the lambda correction with adaptively learned precontrol values also in phases of the tank venting so that the disturbing quantities which are introduced by the tank venting can likewise be learned out; however, the obtained learn values are entered in separate memory locations dependent upon whether they have been determined during the basic adaptation or during the adaptation with tank venting. These learn values are switched to the lambda control as precontrol corrective values in accordance with the time control determining the sequence of the base adaptation phases and tank venting adaptation phases. The invention is also directed to an apparatus for carrying out the steps of the method of the invention.

Abstract: To prevent change of data in a non-volatile programmable, ready-only memory (25) forming, together with a microprocessor (23) a control unit, for example for an automotive vehicle, while permitting programming of the memory from an external programming unit (P, 1), an interface (3, 11, 12) is provided through which a release-enable bus (13) also passes, data being transmitted in accordance with a predetermined characteristic--even or odd parity--, the parity correctness being checked. If the parity is correct, an "enter" signal is provided on the release-enable bus for storing the data; if not, retransmission is attempted for a predetermined number of time, and if it cannot be correctly effected, a malfunction indication output signal is generated.

Abstract: To reduce waste and scrap of automotive electronic computer-type control apparatus constructed in hybrid technology on a substrate, due to malfunction, incorrect programming or desired change in data stored in the memory chip of a read-only memory (ROM) also applied in hybrid technology to the substrate, the substrate has a socket for a standard plug-insertable ROM or programmable ROM hard-wired connected thereto, the memory chip being enabled by application of a voltage applied to a circuit having a severable bridge (12) so that, upon severance of the bridge, the logic voltage applied to the chip will be of the "disable" value, permitting insertion of a standard ROM or PROM (16) into the additional socket (9) for supply of replacement data, the additional socket being hard-wired to a terminal (15) having an "enable" reference potential thereon.

Abstract: The invention is directed to a mixture metering arrangement for an internal combustion engine with a digital data processor, particularly a microcomputer, the signal processing pattern of which is governed by clock pulses, and with a signal generating means which delivers analog output signals. The signal generating means is responsive to operating parameters of the internal combustion engine and is an exhaust gas sensor responsive to the air ratio Lambda. The exhaust gas sensor is used in a closed-loop control system to influence the air-fuel ratio and changes its output quantity at the air ratio of Lambda=1. In this arrangement, a correcting stage corrects the influence of a delay time (t.sub.v) connected with the clocked signal processing on the mixture formation. The delay occurs in the transmission of the change in the output of the sensor. Two methods are indicated for the mode of operation of the correcting stage by means of which a mean value shift of the quantity (F.sub.

Abstract: The invention is directed to an arrangement for metering fuel to a spark-ignition internal combustion engine equipped with a fuel injection system. The fuel metering arrangement includes a control apparatus which generates injection pulses for controlling the injection valves, the pulses being generated at least in dependence upon the rotational speed of the engine. In the event of a failure of the control apparatus, control of the injection valves is switched over to injection pulses derived from the ignition system of the engine. In this arrangement, the transfer of control may be accomplished either by pulling the central plug of the control apparatus or by automatic error detection via a speed relay.

Abstract: A safety device for a controlling unit of an internal combustion engine controlled by a microcomputer includes the following circuits: (a) a source of stabilized voltage which may be subject to fluctuations; (b) a first monitoring circuit responsive to voltage breaks in the voltage source to block the controlling unit for the duration of respective voltage breaks; (c) a second monitoring circuit responsive to the operability of the microcomputer to block the controlling unit for the duration of the resetting time of the microcomputer when a non-operative condition of the microcomputer is detected.

Abstract: The actuation speed of an electromagnetic consumer is increased by means of a charged capacitor which is connected in series with a consumer at such a polarity that its voltage is added to that of the power source. In one embodiment, the capacitor is switched across the power source until it is charged and then it is connected in series with the consumer at such a polarity that its positive pole is grounded while the negative pole is connected to the consumer. In another embodiment, the capacitor is first charged through the electromagnetic consumer and then it is connected with its positive pole to ground and with its negative pole to the consumer.

Abstract: The invention is directed to a method and an apparatus for controlling the air-fuel ratio of the operating mixture supplied to an internal combustion engine. The apparatus includes an oxygen sensor that is responsive to the oxygen content of the burnt operating mixture. The operating state of the sensor is detected by superposing a constant reference quantity on the oxygen sensor output quantity. The resultant of these quantities is fed to at least two comparators having different thresholds. The comparator outputs are processed to detect the operational readiness of the sensor. In this arrangement, the air-fuel ratio of the operating mixture is adjustable in dependence on the output quantity of the comparator to which the higher threshold is applied. This upper threshold and the special course of the Lambda sensor output voltage coact to compensate for the lean shift of the Lambda control during the warm-up phase of the internal combustion engine.

Abstract: To prevent stumbling operation of an internal combustion (IC) engine (E) during warm-up due to switching back-and-forth between control of the air-fuel composition of the mixture being applied to the engine based on a preset, rich mixture and controlled by a lambda sensor, the lambda sensor internal resistance is sensed and, when the internal resistance of the lambda sensor, when exposed to a rich mixture, is substantially less than when exposed to a fuel-lean mixture, an indication is thereby provided that the sensor has reached proper operating temperatures - see FIG. 3 - is capable of providing output voltages within the evaluation range of two threshold circuits (9, 10) which receive reference values from a voltage divider (6, 7, 8) and of resuming control based on the output voltages of the sensor.

Abstract: A current regulator is proposed for use in an electronically controlled, continuously operating gasoline injection system, with the aid of which a control element can be supplied with different current values depending upon the operating states of the engine. In addition to a current regulating phase during active operation, it is possible with the proposed current regulator to reverse the direction of current flow in the control element for the sake of blocking the supply of fuel during overrunning. Towards this end a circuit apparatus links signals relating to rpm, throttle valve position and temperature. Furthermore two safety circuit arrangements are proposed for the current regulator, so that in case of a failure of important components there is no impairment of safety, and emergency operation is assured.

Abstract: Oscillations which would normally occur when the current in the primary winding of an ignition coil is limited to a predetermined value prior to ignition are suppressed by use of a feedback resistor. Specifically, the basic circuit consists of the primary winding of the ignition coil connected in series with a Darlington transistor configuration which, in turn, is connected in series with a measuring resistor, at a common point. The input of the current control system is connected to the common point through an additional resistor, while the output of the control circuit is connected to the input base of the Darlington configuration. Oscillations which might otherwise occur are suppressed by the use of a feedback resistor connected between the input and output lines of the control circuit.

Abstract: A dwell angle control has three counting devices for detecting acceleration. In a first UP/DOWN counter (17), the count in one direction takes place throughout the time the current in the primary circuit of an ignition coil (25) exceeds a current threshold value (I1). The count in the other direction is constant with respect to time. The counts on the first counter are taken over into a second UP/DOWN counter (11) in response to the input signal, the counting direction also being determined by the input signals. When the count in the second counter (11) reaches an adjustable trigger threshold value, the closure time is initiated, the actual ignition time being fixed by an edge of a sensed signal, or the edge of the signal from an ignition computer. The adjustable trigger threshold value is advantageously determined by a third UP/DOWN counter (12) which is set to a fixed value (X) by an edge of the sensed signal and whose counting direction is also determined by the sensed signals.

Abstract: An ingition system for internal combustion engines has dwell angle control apparatus for controlling the switching times of an electronic switch (21) in the primary circuit of an ignition coil (22) in dependence on the signals of a rotating sensor (10) or an ignition computer (11). Specifically, speed dependent counting values are periodically generated in a counting apparatus (13) each being counted down in a further counting apparatus (14) controlled by an edge of the sensed signal or a computed signal. Upon reaching a presettable triggering counting value, the electronic switch (21) is closed (start of dwell period). This triggering value is set by periodic up and down counting processes in a control counter (17) the upwards counting being constant with respect to time and the count-down process being determined by the length of time of current flow above a settable current value through the ignition coil (23).

Abstract: A switching transistor (7, 9) is serially connected with the primary (5) of an ignition coil; current flow therethrough is controlled from an a-c signal generator (16) with respect to an ON threshold level (Ue) to store electromagnetic energy, and an OFF threshold level (Ua) to generate a spark; a variable conductivity circuit (26) controlled from a sensing resistor (8) modifies the response level of the threshold switch (13) with respect to the null or cross-over level of the applied signal. To prevent excessive current flow under idle-speed conditions, in accordance with the invention, the ON threshold level, at least, of the switch is shifted by introducing an auxiliary bias voltage derived from an auxiliary capacitor (36) and connected (37, 38) by the signal source through a diode (38) which prevents application of an auxiliary bias voltage to the threshold switch (13) under extremely low, e.g.

Abstract: Clock pulses are counted to provide a count indicative of speed in a counter that is reset with every revolution of a reference mark. The difference between successive counts is multiplied by a fractional factor, which is not necessarily the same for acceleration and deceleration, then added algebraically to the current count value. The acceleration-corrected speed value is then multiplied by a parameter-dependent digital value obtained from a summing circuit to which various engine condition parameters are supplied and the output of the last-mentioned multiplier is supplied to a comparator to which the current count of clock pulses beginning with the reference mark passage is compared. When the comparator finds the match, spark ignition takes place. Another counter counts the clock pulses following each reference mark for sequencing multiplexers that enable some components to serve in more than one operation, in effect controlling the flow of digital values around various loops in the circuit.

Abstract: In order to reduce the amount of ignition energy supplied to an ignition coil during low speed operation of the engine, an electronic circuit is provided to regulate the open time of the ignition circuit to be constant in an upper engine speed domain and to then obey a predetermined characteristic in the mid-range. The mid-range control is gradually made ineffective at lower engine speeds where the open ignition interval is determined by speed as measured by the duty cycle of the engine ignition transducer. The change of characteristics is obtained with the aid of a control voltage source which generates a speed dependent control voltage causing the discharge time of a capacitor to be extended at low engine speeds and causing the termination of the open time of the ignition to be determined by the transducer output signal.