JPS609368B2 - electronic tuning receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically tuned receiver, and more particularly to an electronically tuned receiver that reduces the power consumption of a storage power supply when the power is turned off.

In recent years, with the rapid development of electronic technology, various types of receivers using electronic tuning methods have been developed.

This electronic tuning controls the reception frequency by controlling the voltage of a variable capacitance diode provided in the tuning section. In this case, various methods have been proposed for controlling the tuning voltage, but from the point of view of stability, one has been proposed in which the instructions are given as a digital value, and this digital value is D-A converted and used as the tuning control voltage. ing. And this D-
Various configurations have been considered for the A converter, but due to problems such as the number of terminals in integration, the D-to-A converter is configured using a pulse synthesizer and a 0-pass filter. This pulse synthesizer divides the output of a pulse oscillator using multiple stages of frequency dividers, and selectively combines the frequency-divided outputs of each stage in accordance with parallel digital signals. The pulse train signal is converted into a serial pulse train signal corresponding to the voltage, and this pulse train signal is passed through a low-pass filter to be converted into a DC voltage. The tuning voltage generation section including these circuits is integrated, and the tuning voltage generation section includes a preset. In this case, the channel selection voltage generation section that includes the brisset circuit must retain its memory contents even when the power switch is turned off. continues to supply power using the However, in the above-mentioned tuning voltage generation section, there are parts that consume power in addition to the memory that stores the reset value, and in particular, the pulse oscillator that supplies pulses to the pulse synthesizer consumes a relatively large amount of power. I end up.

Therefore, power consumption increases when the power switch is turned off, and if an auxiliary power source or the like is used to retain memory when the power switch is turned off, it becomes impossible to hold presets for a long time. In addition, the channel selection voltage generator is constantly supplied with a small amount of power to maintain the preset value, so if a pulse signal is supplied for some reason when the power switch is turned off, it may malfunction, or it may malfunction during reception. It has drawbacks such as the previously selected frequency being moved. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electronically tuned receiver that reduces memory retention power when the power switch is turned off and prevents malfunctions when the power switch is turned off.

Hereinafter, the electronic tuning receiver according to the present invention will be explained in detail using the drawings. The figure shows an electronically tuned receiver according to the present invention.
FIG. 2 is a circuit diagram of a main part showing an embodiment, particularly showing an electronic tuning voltage generating section.

In the figure, 1 is a pulse generator that generates up/down pulses U and D and clock pulses KC by manual operation, and 2 is a binary up/down pulse generator whose count input is the up pulse U or down pulse D of pulse generator 1.
The down counter 2 has a count control terminal 2a that performs a counting operation only when an "L" input signal is supplied. 3 is a pulse oscillator that oscillates only when an "L" input is supplied to the oscillation control terminal 3a; 4 is a pulse oscillator that divides the oscillation signal of the pulse oscillator 3 and outputs the output signal of each stage according to the output signal of the up/down counter 2; Up/up by selecting and compositing
A pulse synthesizer which obtains a serial pulse train with a number of pulses corresponding to the output of the down counter 2, 5 is a low pass filter, and the pulse oscillator 3 and pulse synthesizer 4 constitute a D/A converter. .

Reference numeral 6 denotes a band select switch that selects a band by switching and supplying the direct current output of the low-pass filter 5 to a tuning circuit (not shown), and fixed contacts a to c are in charge of bands A to C, respectively. 7a to 7e are channel select switches composed of non-lock type switches, and 8 is a fixed contact a in charge of bands A to C.
This band select switch 8 and the band select switch 6 are interlocked with each other.

Reference numeral 9 stores the output of the up/down counter 2 at the address specified by the outputs of the channel select switches 7a to 7e and the band select switch 8, or reads out the contents stored at the specified address and stores the output of the up/down counter 2. This read/write memory 9 supplies input signals to the input signal 2 and has a latch function for input signals.

The outputs of the channel select switches 7a to 7e and the band select switch 8 are input, and when the preset switch 11 is off, a load signal is sent to the up/down counter 2 when the output of the channel select switches 7a to 7e occurs. A control circuit that supplies L and also supplies a write signal W to the read/write memory 9 when it is on; 12 is a frequency display that digitally displays the light emitting diode by inputting the upper 5-bit signal of the up/down counter 2; Reference numeral 13 denotes an enable terminal, to which an H signal is supplied when a power switch (not shown) is turned on.

Reference numeral 14 denotes an inverter that inverts the efficient signal supplied to the enable terminal 13, and the output signal of this inverter 14 is supplied to the count control terminal 2a of the up/down counter 2 and the oscillation control terminal 3a of the pulse oscillator 3. ing.

In the circuit configured as described above, an "L" signal is supplied to the enable terminal 13 when the power switch (not shown) is off.

This "L" signal is inverted to an "H" signal by the inverter 4, and this inverted "H" signal is supplied to the count control terminal 2a of the up/down counter 2 and the oscillation control terminal 3a of the pulse oscillator 3. Therefore, the up/down counter 2 stops its counting operation to prevent malfunctions when the power switch is turned off, and the pulse oscillator 3 stops its oscillation operation, and at least the 1'-write memory 9
An auxiliary power source (not shown) is supplied to the device to reduce power consumption when the power switch is turned off. Therefore, power supply when the power is turned off becomes easy. Next, when the power switch is turned on, an "H" signal is supplied to the enable terminal 13, and this "H" signal is inverted to an "L" signal by the inverter 14 and supplied to the count control terminal 2a of the up/down counter 2. At the same time, it is supplied to the oscillation control terminal 3a of the pulse oscillator to start the oscillation operation. In this state, when the pulse generator 1 is operated to generate, for example, an up pulse U, this up pulse U is supplied to the up/down counter 2, and the up/down counter 2 receives the clock pulse output from the pulse generator 1. KC is counted up sequentially. The parallel count output of this up/down counter 2 is
The pulse synthesizer 4 is supplied to a pulse synthesizer 4, where the signals of each stage obtained by dividing the oscillation signal corresponding to the output of the up/down counter 2 are selectively combined and converted into a serial pulse train of the corresponding number of pulses. The output signal of the pulse synthesizer 4 has high frequency components removed by a low-pass filter 5, and becomes a DC voltage signal corresponding to the output of the up/down counter 2. This DC voltage signal is
The signal is applied to a variable capacitance diode of a tuning circuit (not shown) selected by the band select switch 6, and the corresponding frequency is tuned. Further, the upper bit signal of the up/down counter 2 is supplied to a frequency display 12, where the frequency being received is digitally displayed. The above explanation is an explanation of the operation during manual operation. Next, preset channel selection will be explained.

With the desired station selected by the method described above, first turn on the preset switch 11, then turn on any of the channel select switches 7a to 7e corresponding to the channel you want to preset, and the control circuit 1
A write signal W is supplied from 0 to the read/write memory 9, and the band select switch 8 of the read/write memory 9 and the channel select switches 7a to 7a which are turned on are
The count output of the up/down counter 2, that is, the digital signal that is the basis of the tuned frequency being received, can be stored at the address specified by 7e. In this way, desired frequencies are preset for other channels as well. Next, when performing preset tuning, select the band select address where the digital signal corresponding to the desired station is stored. The selection is made using the toggle switch 8 and channel select switches 7a to 7e.

When such an operation is performed, the control circuit 10 supplies the load signal L to the up/down counter 2 since the preset switch 11 is off. As a result, band select switch 8 and channel select switches 7a to 7e
The readout signal of the read/write memory 9 is read in parallel to the up/down counter 2, and its output is sent to the digital synthesizer 4.
The channel selection operation is performed in the same way as in the case of manual operation. In this way, in the present invention, when the pulse oscillator 3, synthesizer 4, read/write memory 9, etc. are composed of a single integrated IC, each part of the integrated circuit is connected to a common power supply. It is possible to supply a main power supply when the power switch is on and an auxiliary power supply when the power switch is off from a common power supply terminal for the integrated circuit, and it is also possible to supply a tuning voltage generator with relatively high power consumption. The operation of the up/down counter 2 and pulse oscillator 3 is stopped by the enable signal generated when the power switch is turned off.
The power consumption of the auxiliary power source is extremely reduced, and malfunction of the up/down counter 2 when the power switch is turned off is prevented.

As explained above, in the electronic tuning receiver according to the present invention, the operation of the up/down counter and the pulse oscillator of the tuning voltage generating section is stopped by the enable signal generated when the power switch is turned off.
This has various excellent effects, such as extremely reducing power consumption for memory retention when the power switch is off, and preventing malfunction of the up/down counter when the power switch is off.

[Brief explanation of the drawing]

The figure is a circuit diagram of a main part showing an embodiment of an electronically tuned receiver according to the present invention. 1...Pulse generator, 2...Up/down counter, 3...Pulse oscillator, 4...
・Pulse synthesizer, 5...Low pass filter, 6,
8... Band select switch, 7a to 7e... Channel select switch, 9... Read/write memory,
10... Control circuit, 11... Preset switch, 12... Frequency display, 13...
...Effective terminal, 14...Inverter terminal.

Claims (1)

[Claims] 1. A pulse generator that generates up and down pulses by manual operation, an up/down counter that counts the output of the pulse generator, and an output of each stage that corresponds to the output of the up/down counter. A D-A converter converts the selected rectangular wave synthesized output through a low-pass filter and supplies it to a tuning variable capacitance diode, stores the outputs of the up/down counter, and stores the stored information. Up・
In an electronic tuning receiver equipped with a read/write memory that supplies a down counter, an enable signal generated when the power switch is turned off disables the up/down counter and the pulse oscillator, and at least disables the read/write memory. An electronic tuning receiver characterized by supplying auxiliary power to memory.