JPS6198014A - Noise pulse eliminating device - Google Patents

Abstract

PURPOSE:To eliminate a noise pulse by connecting a delay time which has a delay time a little bit longer than the pulse width of the noise pulse to the clock terminal of a D flip-flop. CONSTITUTION:A pulse signal inputted to a terminal C is delayed by the delay circuit 2 and inputted to the clock terminal CK of the D flip-flop 3, and the other pulse signal is inputted to the terminal D of the D flip-flop 3. The delay time of the delay circuit 2 is set a little bit longer than the pulse width of the noise pulse and the D flip-flop 3 is clocked with input pulses which are delayed by a time a little bit longer than the pulse width of noise pulses, so only pulses having pulse width longer than the delay time appear at the terminal Q of the D flip-flop 3, so that noise pulses having pulse width longer than said time are all removed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a device for removing noise pulses contained in pulses used in electronic circuits such as television receivers and telephones.Prior art Fig. 3 4(a) is a block diagram of a conventional noise pulse removal device, FIG. 4(a) is a waveform diagram of an input pulse in the device, and FIG.
Figure (b) is also a waveform diagram of the output pulse, and 1 is an integrating circuit in which a resistor and a capacitor are connected in series and both ends of the capacitor are used as output terminals. When there is a noise pulse before and after the input pulse as shown in Fig. 4 (2L), conventionally, the pulse is inputted from the input terminal of the integrating circuit 10 shown in Fig. 3, and as shown in Fig. 4 (b). A pulse with no noise pulses was taken out from the output terminal B of the integrating circuit 1.

Problems to be Solved by the Invention However, when noise pulses are removed from the input pulse using the integrating circuit 1, the output pulse starts at the time when the input voltage of the input pulse rises, as shown in FIG. 4(b). and then
A waveform is drawn that gradually increases as time passes, and when the amplitude of the input pulse reaches 0, the amplitude peaks at that point and gradually decreases. In other words, in conventional noise pulse removal devices, the waveforms of the input and output pulses change, and the falling part of the output pulse is out of phase with the falling part of the input pulse. This creates an inconvenience in that the output pulse needs to be shaped once again.

The present invention has been made in view of the above drawbacks, and provides a noise pulse removal device that removes noise pulses without changing the waveforms of input and output pulses and without causing a phase shift in the falling portion. The purpose is to provide.

Means to Solve the Problem The present invention provides a pulse delay circuit whose delay time is set slightly longer than the amplitude time of the noise pulse included in the input pulse, and a pulse delay circuit that inputs the input pulse to the pulse delay circuit and outputs the pulse. The above object is achieved by using a D-type clip flop using the delayed pulses as a clock for noise pulse removal.

action The effects of this technical means are as follows.

When the input pulse is input to a D-type flip-flop, a pulse with noise pulses removed is output. Further, the pulse is a pulse obtained by removing the portion delayed by the delay circuit from the input pulse, and the phase of the falling portion of the pulse does not shift.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of the noise pulse removal device in this embodiment, FIG. 2 (&) is a waveform diagram of the input pulse in the same device, FIG.
C) is a waveform diagram of the output pulse, and 2 is a delay circuit that delays the input pulse by a certain set time and outputs it, and 3 is a D-type flip-flop that processes the input pulse based on the clock.

Next, the operation will be explained. Figure 2 from terminal C (8L)
When an input pulse with noise pulses before and after a pulse like this is input, the input pulse shown in FIG. 2(b) becomes a delayed pulse delayed by a time T and is outputted to its output side by the delay circuit 2. It is input to the clock input of D type-7 lip-flop 3. Note that the delay time T is set to a time that slightly exceeds the amplitude time of the noise pulse included in the input pulse. On the one hand, the above input pulse is input to the D input of the D type flip-flop 3, and is delayed from the input pulse as shown in FIG. A pulse with no noise pulse is output, except for the amplitude at time T, which is the part where the pulse is generated.

Effects of the Invention The present invention uses a D-type flip-flop whose clock is a delayed pulse obtained by delaying an input pulse by a certain time, thereby eliminating noise pulses having a shorter time than the time delayed by the delay circuit. Therefore, there is an advantage that there is no need to shape the pulse again in the next stage circuit. Further, there is an effect that the waveforms of the input pulse and the output pulse do not change, and furthermore, the phase of the falling edge of the output pulse with respect to the falling edge of the input pulse does not change.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a noise pulse 7-pulse rice removal device according to an embodiment of the present invention, and Fig. 2 (&), (1))
, (C) is the same pulse waveform diagram, Figure 3 is a block diagram of a conventional noise pulp system, Figure 4 e), (b)
is also a pulse waveform diagram. 1...Integrator circuit, 2...Delay/delay circuit,
3...D type-flip flop.

Claims (1)

[Claims] a delay circuit that delays the input pulse by a time slightly longer than the amplitude time of the noise pulse included in the input pulse;
It is characterized by comprising a D-type flip-flop into which the delayed pulse outputted from the delay circuit is input as a clock, and noise pulses are removed by inputting the input pulse to the D-type flip-flop. Noise pulse removal device.