摘要:
A signal voltage from a signal processing path is coupled via an interfacing terminal to an input port of a filter, the output port of which is connected to the base input of a current source transistor to supply thereto a signal voltage which exhibits the filter transfer function. The collector output of the current source transistor is also coupled to the interfacing terminal and conducts a current exhibiting the filter transfer function to the signal path via the interfacing terminal. The base input of the current source transistor is driven with filter output sigals via a low output impedance voltage source (e.g., an emitter follower stage). The impedance presented to the base of the transistor is primarily determined by the low output impedance of the voltage source.
摘要:
A bias source (R7,R8,C24) connected to a summing amplifier (Q1) produces a first DC bias at the amplifier input (emitter) and a second DC bias at the amplifier output (collector). A first circuit node (B) is AC coupled (22) to a luminance signal source (Y1, 18), DC coupled via a first resistor (R4) to the input of the summing amplifier and DC coupled via a first amplifier (28) to a luminance load (Y3,30). A second circuit node (A) is AC coupled (20) to a chrominance signal source (C1,18), DC coupled via a second resistor (R3) to the input (emitter, Q1) of the summing amplifier and DC coupled via a second amplifier (26) to a chrominance signal load (C3,30). A third amplifier (Q2) provides DC coupling of the output of the summing amplifier (Q1) to a composite video signal load (E,40). Advantageously, the circuit provides component to composite conversion with plural buffered outputs which may exhibit different power gains, which are stable notwithstanding load impedance variations and which are DC biased by bias produced at the summing amplifier input as well as its output thereby simplifying the conversion and buffering.
摘要:
A temperature compensation network for an integrated circuit amplifier in a television receiver includes a thermistor mounted physically adjacent to, and electrically connected in parallel with the brightness control potentiometer, to the brightness control terminal of the integrated circuit. By mounting the thermistor in close proximity to the integrated circuit to be controlled, the thermistor is able to compensate for both self-heating of the integrated circuit and ambient temperature variations.
摘要:
A TV system includes a selectively enabled blanking network for introducing blanking into the autopix feedback loop during vertical blanking periods. The TV system includes a contrast control section responsive to color signals whose output is coupled to a brightness control section. Outputs of the brightness control section are combined via a combining means to produce a "combined signal" representative of the luminance component of the image to be displayed. The "combined signal", which is not "blanked" during the vertical blanking (retrace) period, is coupled via a feedback loop which includes a peak detector and a comparator to the input of the contrast control section for controlling its response to the color signals. The selectively enabled blanking network is coupled to the input of the peak detector in the feedback loop for limiting the propagation of the "combined signal" via the feedback loop during vertical blanking intervals.
摘要:
Audio bus receiver includes a pair of bipolar transistors each having a base coupled via a respective resistor to a respective bus receiver input terminal, each having an emitter that is diode coupled to a respective current source and each having a collector coupled via a respective load resistor to a source of reference potential. The emitters are coupled together via a gain control resistor and the collectors are coupled to an output terminal via a differential amplifier. Advantageously, the receiver avoids loading the bus under power-down conditions without requiring the use of stand-by power supplies. Additionally, high common mode rejection is achieved without need for precision matching of components and only a single supply voltage is required for operation.
摘要:
A synchronizing pulse separator for a video apparatus provides horizontal and vertical synchronizing pulses from a composite video signal. The sync separator incorporates a compensation circuit that achieves noise immune operation with composite video signals that provide progressive field display and consequently lack synchronization equalizing pulses. The compensation circuit maintains a sufficient bias level on the sync separator transistor during the vertical blanking interval to prevent premature triggering of the vertical deflection circuit due to noise.
摘要:
A handheld diabetes management device having a plurality of communication modules for communicating with a plurality of medical devices via a shared antenna or multiple antennas, where the handheld diabetes management device includes a first communication module, a second communication module, and an arbitration module. The first communication module selectively communicates in a first frequency band with an insulin infusion pump external to the handheld diabetes management device via a first antenna using a first wireless communication protocol. The second communication module selectively communicates in the first frequency band with a continuous glucose monitor external to the handheld diabetes management device via a second antenna or the first antenna using a second wireless communication protocol. The arbitration module grants permission to communicate to the first communication module and denies permission to communicate to the second communication module when the first and second communication modules request permission to communicate concurrently.
摘要:
A handheld diabetes management device having a plurality of communication modules for communicating with a plurality of medical devices via a shared antenna or multiple antennas, where the handheld diabetes management device includes a first communication module, a second communication module, and an arbitration module. The first communication module selectively communicates in a first frequency band with an insulin infusion pump external to the handheld diabetes management device via a first antenna using a first wireless communication protocol. The second communication module selectively communicates in the first frequency band with a continuous glucose monitor external to the handheld diabetes management device via a second antenna or the first antenna using a second wireless communication protocol. The arbitration module grants permission to communicate to the first communication module and denies permission to communicate to the second communication module when the first and second communication modules request permission to communicate concurrently.
摘要:
A driver for a cathode ray tube includes a black level compensation circuit which generates an offset voltage which tracks the current flowing to the output of the driver and therefore the average picture level (APL). The offset voltage is added as a component of the output voltage so as to increasingly shift the output voltage toward black as the APL increases. This compensates for CRT gamma non-linearities and for light scattering effects which might otherwise cause the loss of perceived detail and sharpness in dark areas of a high APL image. In the disclosed embodiment, the driver comprises a cascode amplifier and the offset voltage generating element includes a capacitively bypassed resistor connected in a reference voltage network connected to the emitter circuit of the lower (common emitter configured) transistor of the cascode amplilfier.
摘要:
A television receiver provides a noise-free set up signal by automatically selecting an unused baseband video input terminal, or an unused pair of SVIDEO input terminals. Selection of the unused terminals provides a D.C. level to the luminance path, and allows the horizontal oscillator to free-run. In addition to selecting an unused video input terminal, the subject apparatus automatically increases the brightness level a few steps to simulate a 7.5 IRE flat field (commonly known as set up). The above-listed steps may be performed manually by a service technician, for television receivers not incorporating apparatus for automatically performing the steps.