KR960005186Y1 - Common use circuit for pal b/g and pal i audio terminal - Google Patents

Abstract

None.

Description

ARM B / G and ARM I audio stage common circuit

1 is a circuit diagram of the present invention.

* Explanation of symbols for main parts of the drawings

10: IC for FM audio detection F1: 5.5MHz filter

F2: 6 MHz filter T1: 5.5 MHz tank circuit

T2: 6MHz tank circuit

The present invention relates to a common circuit of the arm B / G and arm I audio that can receive the radio B / G and arm I broadcasting in Europe.

In Europe, ARM B / G broadcasting system and ARM I broadcasting system have a difference of 5.5MHz and 6MHz, respectively.

Therefore, a single tuner cannot share the B / G and Arm I broadcasts in common, and until now, it has been using a 0.5MHz oscillator to cover the quantum 0.5MHz difference for public reception.

In this case, however, a mixer stage and a filter stage are required in addition to the oscillation stage, which entails a complicated circuit configuration and a cost increase.

The present invention proposes an audio-stage common circuit that enables arm B / G and arm I broadcast reception through a simple circuit configuration.

The present invention allows the sif input signal to be input to the FM detection IC via the arm B / G filter and the arm I filter, and the two FM detection ICs are provided with an arm B / G tank circuit and an arm I tank circuit. It is implemented by creating a resonance point of.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the sif signal is input to the FM audio detection IC 10 through a parallel circuit of an arm B / G 5.5 MHz filter F ₁ and an arm I DYD 6 MHz filter. In the FM audio detection IC 10, a 5.5 MHz tank circuit for arms B / G and 6 MHz tank circuits for arms I composed of L and C are provided.

Referring to the operation and effects of the present invention configured as described above are as follows.

In FIG. 1, the input sif signal passes through a 5.5 MHz sif band filter (F ₁ ) and a 6 MHz sif band filter (F ₂ ) to selectively pass the sif band of arm B / G and the sif band of arm I and then detect FM audio. It is input to the IC 10 for use. These sif signals are formed by respective 5.5 MHz L. C IF tank circuits (T ₁ ) and 6 MHz L, C, IF tank circuits (T ₂ ), each having a relatively high Q value, to form an FM audio detection IC. It is detected by (10) and output as an audio signal.

Accordingly, the arm B / G and arm I audio stages can be shared.

As described above, the present invention has an arm B / G band pass sif filter and an arm I band pass sif filter, and an arm B / G sif I resonant tank circuit and arm I sif resonator provided in the FM detection IC. Since two resonance points are formed through the tank circuit, arm B / G and arm I broadcasts, which are broadcast in Europe, can be received in common, and the 0.5 MHz oscillator mixer stage required in the common circuit of the standard is required. And a unique effect that can solve the problem of product cost rise due to the filter stage required.

Claims (1)

In the arm broadcast method common reception circuit, the sif input signal is input to the FM audio detection IC 10 through the 5.5 MHz band filter F ₁ for the arm B / G and the 6 MHz band filter F ₂ for the arm I. And arm B / G and I 2 point resonance 5.5 MHz tank circuit T ₁ and 6 MHz tank circuit T _{2 in} the FM audio detection IC 10. And ARM I audio stage common circuit.