Abstract: A write data precompensator system is described which comprises a delay element circuit (12) which receives a clock signal and outputs a delayed clock signal which includes a programmable selectable delay in the rising edge of the clock signal. The amount of delay is received using a delay voltage level generated by a delay level circuit (16) which receives delay magnitude control values in digital form. A reference level circuit (18) also generates a continuous level voltage level so that the delay element circuit (12) can instantly change between a delayed operation and an undelayed operation without waiting for the delay voltage level to adjust.

Abstract: A circuit (10) for storing and retrieving data is provided. Circuit (10) stores data on a data fuse (20). The values of the stored data may be established by comparing the data fuse (28) with a test fuse (22) using a storage and sensing circuit (12). The value of the data fuse (20) may be set by a fuse setting circuit (14). Additionally, a value may be substituted for the data fuse (20) using a flip flop (16) and an output logic circuit (18).

Abstract: A dual function sensor particularly useful with vehicular coolant systems indicates when a coolant liquid becomes corrosive to such cooling system materials as well as when the liquid falls to a low level condition. A reference and a sense electrode are used to probe the condition of the coolant liquid. Integral electronics provide signal conditioning and transmitting to indicate both corrosive and low level coolant conditions. The sensor assembly mounted directly onto a tubular coupling on the vehicle radiator by pushing the assembly onto the coupling until a spring wire element snaps past a lip formed on the free distal end of the coupling. An electrical connector shroud extends from the assembly and accommodates a mating male connector which is pushed onto the shroud until a clip mounted on the male connector snaps over a locking tab located on the shroud. The male connector typically is connected to an engine control module (ECM).

Abstract: An oscillator circuit having a coil and capacitor tank circuit, a clamp resistor connected at one end to the coil and a switch coupled to the clamp resistor and coil. The switch is operative to close in response to a first input logic clamp signal and shunt the coil with an impedance that causes the oscillation to stop quickly. In response to removal of the input logic clamp signal the tank circuit starts to oscillate from a known state. Preferably the clamp resistor has a value which equalizes the tank currents for the clamped and peak unclamped states.

Abstract: A dropping resistor and a pair of differential current steering pairs coupled to the resistor with each operable to draw and cease drawing current through the resistor in response to associated corresponding input signals. An integrator is coupled through an emitter follower to one end of the resistor for integrating the current due to the difference in voltage from that voltage established when only one of the pair draws current through the resistor. Preferably the resistor is integrated on a semiconductor chip together with the remainder of the charge pump and integrator circuitry.

Abstract: A voltage controlled oscillator circuit of a type having a tank circuit for generating oscillations which includes a means for establishing a fixed bias voltage with respect to ground at a bias end of said tank circuit, means for drawing current from an a.c. end of said tank so as to control the tank gain, and an AGC capacitor. A constant current source is coupled to the AGC capacitor for supplying it with a constant charging current. Means are provided for discharging the AGC capacitor at a voltage level determined by a ratio of resistors and a transistor emitter-base ratio.

Abstract: A dual function sensor particularly useful with vehicular coolant systems indicates when a coolant liquid becomes corrosive to such cooling system materials as well as when the liquid falls to a low level condition. A reference and a sense electrode are used to probe the condition of the coolant liquid. Integral electronics provide signal conditioning and transmitting to indicate both corrosive and low level coolant conditions. The sensor assembly mounts directly onto a tubular coupling on the vehicle radiator by pushing the assembly onto the coupling until a spring wire element snaps past a lip formed on the free distal end of the coupling. An electrical connector shroud extends from the assembly and accommodates a mating male connector which is pushed onto the shroud until a clip mounted on the male connector snaps over a locking tab located on the shroud. The male connector typically is connected to an engine control module (ECM).

Abstract: A clamp circuit which breaks down under application of high voltage is connected to an input pin to be protected through a unidirectional device such as a diode. A voltage supply is connected to the discharge path between the unidirectional device and the clamp. The voltage supply will therefore supply any leakage currents which may be drawn by the clamp during normal operation.

Abstract: A current to frequency converter having an operational amplifier with two inputs, an output, and a feedback capacitor connected between one input and the output to produce an output voltage waveform having a rate of change proportional to the input current between a first and second predetermined voltages. A level detector and active switching devices to detect the second predetermined voltage level and reset the voltage level of the waveform to the first predetermined voltage level. The level detector produces an output signal when the second voltage level is reached. The output signals form a digital pulse stream having a frequency proportional to the input current.

Abstract: A phase space locked loop system used for performing indirect frequency modulation. A phase locked loop is comprised of a phase detector coupled to a low pass filter coupled to a voltage controlled oscillator with a feedback loop to the phase detector. Input signals provided by a crystal controlled oscillator are fed to the phase detector. A phase difference other than 90.degree. between the voltage controlled oscillator output and the input signal will result in the phase detector generating an error voltage which is filtered by the low pass filter to alter the voltage controlled oscillator until its phase is 90.degree. from the input signal. A modulating signal is injected into the phase locked loop which causes the voltage controlled oscillator to momentarily change frequency until the output of the phase detector changes enough to balance the modulating signal.