Abstract: An analog-digital converter designed to provide digital data by converting analog input voltage signals into pulse signals by a voltage-frequency converter, and counting said pulse signals by a counter, the improvement being that the A-D converter comprises a sequence controller which selectively supplies low-level or high-level input voltage signals to the A-D converter before analog input signals being measured are received therein.

Abstract: An analog-digital converter designed to provide digital data by converting analog input voltage signals into pulse signals by a voltage-frequency converter, and counting said pulse signals by a counter, the improvement being that the A-D converter comprises a sequence controller which selectively supplies low level- or high level- input voltage signals to the A-D converter before analog input signals being measured are received therein.

Abstract: An injector driving circuit includes a first diode forwardly coupled between one end of a solenoid coil and a positive power supply terminal, a capacitor with one end grounded, a second diode forwardly coupled between the other end of the coil and the capacitor with respect to the positive power supply terminal, a switching transistor coupled between the other end of the coil and the ground and connected to be turned on in response to a driving input signal, a current detecting circuit for detecting current flowing through the coil and producing an output signal when detecting that the coil current has reached a predetermined value, and a switching circuit coupled between the one end of the coil and the other end of the capacitor and connected to be closed and opened in response to the driving input signal and the output signal of the current detecting circuit, respectively.

Abstract: An analog-digital converter designed to provide digital data by converting analog input voltage signals into pulse signals by a voltage-frequency converter, and counting said pulse signals by a counter, the improvement being that the A-D converter comprises a sequence controller which selectively supplies low-level or high-level input voltage signals to the A-D converter before analog input signals being measured are received therein.

Abstract: A pulse train converter converts a first pulse train into a second pulse train of a higher frequency. The pulse train converter comprises a pulse generator for generating pulses having a specified frequency, a frequency divider for dividing the output frequency of the pulse generator by .sub.2 M/n, where n denotes an integer and M denotes the number of parts into which the time period of the pulses contained in the first pulse train is divided by the pulses contained in the second pulse train, a counter which is reset upon receipt of each pulse of the first pulse train and starts to count the output pulses from the frequency divider, and a register for storing the count of the counter upon receipt of each pulse of the first pulse train. The lower order n bits of the output of the register are supplied to compensation signal generator circuit, and the remaining higher order bits are preset in a preset counter as a reference value.