摘要:
A four wheel drive working vehicle having a front wheel transmission switchable between a standard position for driving front wheels at substantially the same speed as rear wheels, and an accelerating position for driving the front wheels at a higher speed than the rear wheels; right and left side brakes for acting on the right and left rear wheels, respectively; a control device for switching the front wheel transmission from the standard position to the accelerating position when the front wheels are steered in excess of a first predetermined angle rightward or leftward from a straight running position, and for operating one of the right and left side brakes inwardly with respect to turning of the vehicle when the front wheels are steered in excess of a second predetermined angle rightward or leftward from the straight running position; and a governor for governing operation of the control device in response to a running speed of the vehicle. The governor is operable to prohibit control of the front wheel transmission and side brakes when a propelling transmission is set to a high speed position, to allow control of the front wheel transmission and prohibit control of the side brakes when the propelling transmission is set to an intermediate speed position, and to allow control of the front wheel transmission and side brakes when the propelling transmission is set to a low speed position.
摘要:
A rubidium oscillator or a cesium oscillator is used as a high stability oscillator, and an OCXO being a metastable oscillator which is inferior in a long-term frequency stability compared with the above oscillators but has a high short-term frequency stability is used as a backup. There is prepared a table in which an elapsed time since an occurrence of an abnormality in the high stability oscillator and weighting (use ratio) of use of the both oscillators is corresponded, and by using this table, after the high stability oscillator recovers, an oscillation frequency of the metastable oscillator is used by 100% initially, but thereafter the weighting (use ratio) of use of the metastable oscillator is made smaller and the use ratio of the high stability oscillator is made larger in stages.
摘要:
The provision of a technique capable of determining a state where PLL control does not operate normally instantly or in advance in a frequency synthesizer that frequency-divides, A/D converts, and quadranture-detects a frequency signal from a voltage controlled oscillating unit, and extracts a rotation vector rotating at a frequency difference between the frequency signal used for the detection and the A/D converted frequency signal, and integrates a difference between a frequency of the above rotation vector and a set frequency to set an integration result as a control voltage to the voltage controlled oscillating unit. The control voltage to be input to the voltage controlled oscillating unit is monitored, and it is determined whether or not a level of the monitored control voltage deviates from a set range determined in advance, and an unlock detection signal is output. In a structure in which the rotation vector is multiplied by a reverse rotation vector reversely rotating at a frequency determined in rough increments according to the set frequency to reduce a velocity of the rotation vector, a determination result whether or not a length of the rotation vector whose velocity is reduced (a scalar quantity) or a correction signal for gain control deviates from a range set in advance is further considered.
摘要:
Provided is a PLL circuit improving reliability while suppressing power consumption without degrading noise characteristics. The PLL circuit includes a PLL IC that divides an output frequency Fout from a VCO, compares phase with a reference signal, and feeds back a phase difference as a control voltage to the VCO. A control circuit is capable of finely setting both of a reference frequency Fref and an output frequency Fdds in a DDS circuit, and the DDS circuit generates folding signals of Fdds for Fref and an integral multiple frequency thereof based on the combination of the frequencies. A first AMP amplifies a signal, a variable filter selects a desired Fdds (desired) and a second AMP amplifies the signal and supplies the same to the PLL IC as a reference signal. The control circuit further supplies a division ratio N to the PLL IC.
摘要:
In adopting a structure in which an oscillator circuit unit and an instrument main body including a measuring unit are separately formed in a sensing instrument measuring the concentration of or determining the presence/absence of a substance to be sensed by using a quartz sensor, the present invention has an object to enable the instrument main body side to know an oscillation frequency of the connected oscillator circuit unit. A plurality of band-pass filters having pass characteristics corresponding to oscillation frequencies of the oscillator circuits respectively are provided in the instrument main body side to sort frequency signals, it is determined whether or not levels of the sorted frequency signals are equal to or higher than a threshold value, and a switching unit is controlled so as to connect a channel having a signal level equal to or higher than the threshold value to the measuring unit, and a reference frequency used in the measuring unit, for instance, is selected according to the frequency of the frequency signal corresponding to this channel.
摘要:
In order to enhance stability of a discharge lamp at the time of dimming lighting even in the case where a light output is lowered, a direct current superimposing circuit superimposes a direct current voltage on an alternating current voltage applied to a fluorescent lamp, and a dimming signal correction circuit receives a detection value of a direct current voltage detection circuit and a dimming signal that is from an outside, outputs a dimming signal higher in level than the dimming signal in the case where the detection value of the direct current voltage detection circuit exceeds a first threshold value, and decreases the level of the outputted dimming signal to the level of the inputted dimming signal in the case where the detection value of the direct current voltage detection circuit falls down below a second threshold value that is equal to or less than the first threshold value. Then, an amount of alternating current power supplied to the fluorescent lamp by an inverter circuit is increased and decreased in response to fluctuations of the level of the dimming signal outputted by the dimming signal correction circuit, whereby the fluorescent lamp is dimmed.
摘要:
An illumination lighting apparatus is connected to, as an external apparatus, any of a human body sensing sensor configured to detect presence/absence of a person, an illuminance sensor configured to detect space illuminance, and a dimmer which arbitrarily adjusts the space illuminance, and is configured to produce an output control signal for controlling an optical output of a light source based on a signal output from the external apparatus. The illumination lighting apparatus includes: an external apparatus determining unit configured to determine which kind of the external apparatus is connected based on the signal output from the external apparatus; and a signal processing unit configured to produce the output control signal based on the signal output from the external apparatus.
摘要:
A VCO driving circuit and a frequency synthesizer wherein the impedance viewed from a VCO control terminal is reduced to prevent the VCO phase noise characteristic from degrading. A VCO driving circuit and a frequency synthesizer having the VCO driving circuit, which comprises a coarse adjustment DAC that receives a digital data, which has a coarse adjustment frequency, to output an analog signal; a fine adjustment DAC that receives a digital data, which has a fine adjustment frequency, to output an analog signal; a low response speed LPF5 that removes noise from the output signal from the coarse adjustment DAC and then provides the resultant signal as an input to a VCO control terminal; a high response speed LPF7 that converts the output signal from the fine adjustment DAC to a voltage, thereby smoothing the signal; a resistor that connects an input stage of the LPF5 to that of the LPF7; and a capacitor used for providing a capacitive coupling such that the output of the LPF7 is added to that of the LPF5.
摘要:
An illumination apparatus, which controls a supply power supplied to a lamp according to an accumulated interval of on-time and a light control signal, is configured in which a maximum supply power supplied to the lamp according to the accumulated interval of on-time is supplied to the lamp when the supply power to the lamp corresponding to the light control signal is above the maximum supply power to the lamp according to the accumulated interval of on-time at a point when the illumination apparatus is turned on or the lamp starts lighting. When the light control signal is operated so as to exceed a level of the maximum supply power to the lamp according to the accumulated interval of on-time or the light control signal varies more than a prescribed level, the supply power is shifted to an adjustable condition so as to be higher than the maximum supply power to the lamp according to the accumulated interval of on-time.
摘要:
A digitally controlled PLL oscillation circuit has a VCO, a frequency divider, a reference oscillation circuit, an A/D converter, a phase comparator, a digital filter, a D/A converter, and an analog filter. A reference signal supplied from the reference oscillation circuit is output through a narrow-band crystal filter (MCF) to the A/D converter to cancel noise, jitter and a spurious wave included in the reference signal, making it possible to prevent the phase noise characteristic and spurious characteristic of a VCO output from being degraded.