close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPS5377447

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPS5377447
Description t name of the invention
Protection circuit
3. Detailed Description of the Invention The present invention relates to a protection circuit for
protecting a pickup source such as a signal source such as an audio device, that is, an MO type
car) ridge, etc., and a microphone. In general, in an amplifier for amplifying a signal from a signal
source such as an MOi cartridge, the power is supplied until the steady state is reached and the
power is turned off until the non-operating state is reached. An unstable transient state exists,
and in this transient state, a large AC-like transient current may occur in the input stage of the
amplifier. Among the amplifiers, an amplifier for electromagnetic signal sources such as an MO
type cartridge, for example, In the MO blade cartridge head amplifier, there are many turtles
having a circuit configuration in which the above-mentioned transient current flows directly to
the in- one bead of the power generation coil of the signal source to be discharged. However, in
the MO type cartridge, since the generating coil is vibrated as is well known, it is necessary to
lighten the coil in a lightweight manner and to be tightly wound to be able to detect minute
vibration, so this is why A very fine zll diameter wire is used as the wire, so the coil current
resistance is very small. The inventor of the present invention has made it possible to repeat the
island closing of the current of the amplifier as described above and repeat that EndPage: 1 L
transient current flows in the impedance of the coil of the MO type cartridge etc. It is necessary
to protect the MO blade cartridge film from the above-mentioned transient current in the input
stage of the amplifier, especially in the case of the HE-Rad amplifier for the MO type cartridge.
Recognized that there is. Heretofore, the effects of such transient currents have not been taken
into consideration in particular, so it has been the case that no measures have been taken for
protection against transient currents. The present invention has been made in view of the above
10-04-2019
1
circumstances, and a switch element is connected between the input end of the amplifier of the
head amplifier for MO type blade cartridge and the ground, and the switch element is switched in
the transient state immediately after the power supply is switched. To discharge the current
generated in the transient state to the input stage of the amplifier through the switch element,
whereby the transient current does not flow to the impedance of the signal source such as the
MO type blade cartridge. To preserve the signal source. DETAILED DESCRIPTION OF THE
PREFERRED EMBODIMENTS Referring now to the drawings, an embodiment of the present
invention will be described. FIG. 1 is a view showing an embodiment for protecting an
impedance, that is, a coil using an MO type blade cartridge as a signal source. One end of 2Fi is
connected to the input terminal 4 of the amplifier 80 and the other end is grounded.
A DC current is supplied from the AC power supply input terminal 6 to the power supply
terminal 5 of the amplifier 8 through the power supply switch 7 and the power supply circuit 8.
The output terminal 9 of the amplifier 8 is connected to a not shown amplifier-a subsequent
amplifier such as an equalizer amplifier. Further, the input terminal 4 of the amplifier 8 is
grounded via a switch element, for example, a normally closed contact type M, a normally closed
contact 10a of the magnetic relay 10 and a capacitor 11 in series. The solenoid 10'bII'i of the
electromagnetic relay 1 'is connected to a relay drive circuit 12 for conducting current to the
solenoid to open the contact 10b. The relay driving circuit 12 drives the relay IO with a
predetermined time after the power switch 7 is closed, and releases the relay 10 by a
predetermined time Tb after the power switch 7 is opened. It is configured to Here, the delay
time T &, 'Ilb will be described with reference to FIG. If the power supply switch 7 is closed at
time 1o and opened at time tl, the power supply voltage V applied to the primary side of the
power supply circuit 8 rises at time t6 and falls at time t6. The voltage transformed and rectified
by the power supply circuit 8, that is, the amplifier drive voltage applied to the amplifier 8, rises
for a predetermined time T from time t0 based on the characteristics of one transformer,
capacitor, etc. , And after a lapse of time T, it becomes stable. The amplifier drive voltage v2 is a
predetermined time T! From time t4. The fall is started with a delay of one, and after a lapse of
time T, it becomes zero after a lapse of time, and the operation of the amplifier 8 is stopped.
Under such conditions, the relay drive [78 rise delay time T & supplied by the relay drive circuit
12 is the amplifier drive voltage V! The time to reach stability (T, set to a time longer than + T,
and also relay drive voltage V. The fall delay time Ttl is set to a time shorter than the time until
the start of the fall of the amplifier drive voltage. That is, as shown in the figure, the relay drive
voltage V rises after the power supply switch is closed and the amplifier drive voltage has
become stable, and the power supply switch 7 is closed and then the amplifier drive voltage V
starts falling. Set so that the relay drive voltage V falls. In the above embodiment, after the power
supply switch 7 is closed, until the time Ta (> 't'1 + lj- elapses, the solenoid l (the drive voltage is
applied to l and there is no EndPage: 2, the contact 10 & is closed Maintaining the state, the
amplifier 80 input terminal 4 is grounded via the capacitor 11.
10-04-2019
2
Therefore, the transient current generated in the input stage of the amplifier 80 is discharged
through the capacitor 11 until the time (TI + T elapses) after the power supply switch 7 is closed,
and the MO type blade cartridge 1 coil 2 hardly flows. When time Ta elapses after closing switch
7, drive voltage is applied to solenoid 10b to open contact 10 &, thereby opening power switch
7, and time rb (<T,) has elapsed from this opening time. When this occurs, the drive voltage of
the thread monoid 10'b is cut off and the contact 10 & is closed again, whereby the amplifier 80
input terminal 4 is grounded via the capacitor 11. Therefore, the transient current generated in
the input stage of the amplifier 80 is discharged through the capacitor 11 after time (7) 1 has
elapsed since the power supply switch 7 was completely opened. As apparent from the above
description, after the power supply switch 7 is closed and then stabilized, and after the power
supply switch 7 is opened and stabilized, the amplifier 80 input terminal 4 is completed. Is
grounded through the capacitor 11, the fault current generated in these states is discharged
through the capacitor 11, and in the steady state, the signal from the fill 2 of the cartridge 1 is
not discharged and is input to the amplifier 8 Be done. Of course, the switch element is not
limited to the electromagnetic relay, and a contactless switch element such as a transistor may be
used. The delay time T'b after closing the power supply switch 7 does not necessarily have to be
present, and may be zero. That is, the contact 10 & of the embodiment may be closed at the same
time as the power switch 7 is opened. As described above, according to the present invention,
since the transient current generated in the (8) FIG. 1 input stage of the amplifier is discharged
through the switch element, the transient current is a signal source such as an MO type blade
cartridge coil. It is possible to effectively prevent deterioration or damage of the impedance of
the coil of the signal source without being discharged by the impedance alone.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a connection diagram showing an embodiment
of the present invention, and FIG. 2 is a diagram showing voltage waveforms of respective parts
in the embodiment of FIG. 1 · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · · · · · · · 10 · · · · · · · · · · · · · · · · 10 · · · · · · · as an electromagnetic relay as a switch element.
Attorney patent attorney *, E * (). No (9) Voltage EndPage: 3
10-04-2019
3
Документ
Категория
Без категории
Просмотров
0
Размер файла
11 Кб
Теги
description, jps5377447
1/--страниц
Пожаловаться на содержимое документа