JPS6248405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a remote control oscillator used as a receiving side of a remote control device in a television receiver or the like.

Conventional configurations and their problems In recent years, there has been a growing movement to increase added value by adding remote control functions to home appliances such as televisions and videos.

A conventional remote control self-running oscillator will be described below. Figure 1 is a block diagram of a conventional remote control self-running oscillator, Figure 2 is a circuit diagram showing the specific configuration of the main parts of Figure 1, and Figures A to C are the circuit diagrams of Figure 2. The main part self-running oscillation waveforms are shown. Here, 1 is a constant voltage power supply, 2 is a charging/discharging circuit, 3 is a controlled system, and 4
is a rectifier circuit, 5 is an impedance converter, 6 is a remote control switch circuit, 7 is a pulse power source 8 is an n-gate SCR, 20 is a remote control switch, 10 is an impedance conversion transformer, 11 is a rectifier diode, 12 is a load resistor, 13 is a smoothing capacitor, 14 and 15 are charging and discharging resistors, and 16 is a charging and discharging capacitor. Note that point A is n-gate SCR
8, point B indicates the gate voltage of n-gate SCR 8, and point C indicates the average value of the output voltage of the pulse power supply.

The operation of the conventional remote control self-running oscillator configured as described above will be described below.

Now, when the remote control switch 20 connected to both ends of the primary side of the impedance conversion transformer 10 is open, the impedance conversion transformer 1
Since the secondary impedance of 0 is very large, the rectifier diode 11 is connected to the pulse power source 7.
_The voltage at point B, which is supplied through
It will be like between ~t ₁ . Next, remote control switch 2
If 0 is closed, impedance conversion transformer 1
The secondary impedance at point C becomes smaller, the pulse power supply voltage at point C decreases, and the rectifier diode 11
The voltage at point B, which has been _rectified by becomes.

Furthermore, when the remote control switch 20 is closed, the charge in the capacitor 16 is gradually discharged to the anode of the n-gate SCR 8 through the resistor 15, and when the anode voltage drops below the turn-off voltage, The gate SCR 8 is turned off, and at this time the voltage at point B becomes a high voltage as at time t ₂ in FIG. When the voltage becomes higher than the voltage at point B, n
Gate SCR8 is turned on. The voltage waveform at point B at this time is as shown between times _t2 and _t3 . In this way, the n-gate SCR8 repeatedly turns on and off,
At point B, a free-running oscillation voltage waveform as shown in FIG. 3B occurs.

However, in the conventional remote control self-running oscillator as described above, when the flyback pulse of a television receiver is used as the pulse power supply 7, the voltage fluctuates in proportion to the amount of change in brightness and darkness of the screen, and the pulse power supply voltage 7 fluctuates and the average value of the pulse voltage applied to point C becomes as shown in Figure 3 C, and the voltage between times t ₄ and t ₅ is higher than that between times t ₁ and _{t 3} . , the time between _{t4 and t5} from when the voltage at point B becomes high and the voltage at point A (anode voltage) of the n-gate SCR8 becomes higher than the voltage at point B from _the turn-off voltage, and B Since the time from time t ₅ to _{t 6} from the point voltage to the point voltage becoming lower than the turn-off voltage becomes longer, the free-running oscillation period becomes longer.

Moreover, the pulse power supply voltage 7 is reversely changed to the time t ₆ in FIG.
If the voltage becomes lower than that between times t ₁ and _{t 3} , such as between t ₈ and t 8, the free-running oscillation cycle will become shorter for the opposite reason to the above, and the fluctuation of the pulse power supply voltage 7 will cause the remote control free-running The disadvantage was that the period of oscillation fluctuated.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks, and aims to provide a remote control oscillator with a constant free-running oscillation period.

Structure of the Invention The present invention includes a charging/discharging circuit connected to the anode of an n-gate SCR, a controlled system and a rectifier circuit connected to the gate of the n-gate SCR, and an impedance conversion that changes the output voltage from the rectifier circuit. a remote control free-running oscillator comprising: a pulse power source that is a power source for the impedance converter; a constant voltage source that charges the charge/discharge circuit; and a bias circuit at a connection point between the rectifier circuit and the n-gate SCR. By biasing the gate voltage of the n-gate SCR to a constant voltage using the aforementioned bias circuit, it is possible to make constant the fluctuation in the oscillation period for remote control due to the fluctuation in the pulse power supply voltage.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the remote control oscillator of the present invention will be described. FIG. 4 is a block diagram of a remote control self-running oscillator according to an embodiment of the present invention, FIG. 5 is a circuit diagram showing a specific configuration of the main part of FIG. 4, and FIGS.
5 shows the free-running oscillation waveforms of the main parts of FIG. 5, respectively. Components in the figure that have the same functions as those in FIGS. 1 and 2 are given the same numbers.

In FIG. 4, 9 is a bias circuit; in FIG. 5, 17 and 18 are bias voltage dividing resistors;
A diode 19 biases the voltage at the intersection of the dividing resistors 17 and 18 to the gate of the n-gate SCR8.

The operation of the remote control self-running oscillator of this embodiment configured as described above will be explained below. When the remote control switch 20 is closed, the secondary impedance of the impedance conversion transformer 10 becomes smaller, the pulse power supply voltage at point C decreases, and the voltage B rectified by the rectifier diode 11 decreases.
The voltage at the point also decreases, but this time division resistor 17,1
When the voltage at point B is lower than the voltage D at the intersection of 8 and 8, the diode 19 is turned on, and the bias voltage at point D is applied to the gate of the n-gate SCR8, making this gate voltage lower than the anode voltage and as shown in FIG. 6C. If the voltage at point D is set higher than the fluctuating voltage of the pulsed power supply, the n-gate SCR8 is turned on.

Furthermore, when the remote control switch 20 is closed, the charge in the capacitor 16 is gradually discharged to the anode of the n-gate SCR 8 through the resistor 15, and when the anode voltage drops below the turn-off voltage, the n-gate SCR 8 is off,
At this time, the voltage at point B becomes a high voltage, as shown between times _t1 and _t2 in FIG. 6B. Next, the resistor 14 connected to the constant voltage power supply 1 starts charging the capacitor 16, and when the voltage at point A becomes higher than the voltage at point B biased by the dividing resistors 17 and 18 and the diode 19, n Gate SCR8 is turned on. The voltage waveform at point B at this time is at time t ₂ in Figure 6B.
It will be like between ~ _t3 . In this way, n gate
SCR8 repeats on and off, but even if the pulse power fluctuates, the bias circuit keeps it at point B.
As shown in FIG. 6, a voltage waveform with a constant period of free-running oscillation is generated.

As described above, according to this embodiment, even if the pulse power supply voltage fluctuates, the dividing resistors 17 and 18
Since the n-gate voltage is biased at a constant level by the diode 19, the time between t ₂ and _{t 3} from when the voltage at point A becomes higher than the voltage at point B from the turn-off voltage, and from the voltage at point B to turn-off. Since the time from t ₃ to _{t 4} until the voltage becomes lower than the voltage is constant, the period of oscillation for remote control self-running can be kept constant even if the pulse power supply voltage fluctuates.

Although this embodiment has been described using a flyback pulse as a pulse power source, the present invention is effective not only when using a flyback pulse but also when using a pulse power source whose voltage value fluctuates. .

Effects of the Invention By providing a bias circuit that maintains the gate voltage of the n-gate SCR constant, the present invention can make the period of oscillation for remote control free-running due to fluctuations in the pulse power source constant, and when the pulse power source is used, e.g. Stable remote control operation is possible even when using flyback pulses.

[Brief explanation of the drawing]

Figure 1 is a block diagram of a conventional remote control self-running oscillator, Figure 2 is a circuit diagram showing the specific configuration of the main parts in Figure 1, and Figure 3 is a free-running main part of the circuit in Figure 2. 4 is a block diagram of a remote control oscillator according to an embodiment of the present invention, FIG. 5 is a circuit diagram of a main part of the same embodiment, and FIG. 6 is a main part of the circuit of FIG. FIG. 2 is a self-running oscillation waveform diagram. 1... Constant voltage power supply, 2... Charge/discharge circuit, 3...
Controlled system, 4... Rectifier circuit, 5... Impedance converter, 6... Remote control switch circuit, 7...
Pulse power supply, 8...n gate SCR, 9...bias circuit.

Claims (1)

[Claims] 1. A charging/discharging circuit connected to the anode of the three-terminal rectifier, a controlled system and rectifier circuit connected to the gate of the three-terminal rectifier, and an impedance converter that changes the output voltage from the rectifier. An oscillator for remote control comprising a pulse power source that is a power source for the impedance converter, a constant voltage power source that charges the charge/discharge circuit, and a bias circuit that biases a connection point between the rectifier circuit and the three-terminal rectifier.