JPS5829635Y2 - synchronous oscillation circuit - Google Patents

Description

[Detailed Description of the Invention] The present invention provides, for example, as shown in FIG.
The present invention aims to provide a synchronous oscillation circuit which can obtain an output pulse pb after a predetermined period t2 after the pulse Pa is supplied.

Let's explain one example below.

In FIG. 1, the emitters of transistors 1 and 2 are commonly connected, a pulse Pa is supplied to the base of transistor 1 through an input terminal 11, and a reference voltage vr is supplied from a variable resistor 21 to the base of transistor 2.

A charging/discharging capacitor 31 is connected between the collector of the transistor 1 and the ground, and a transistor 3 is connected between the power supply terminal 13 and the hot side of the capacitor 31 as a constant current source. A switching diode 41 and a transistor 4 as a sink type constant current source are connected in series between the hot side of the connected and disconnected capacitor 31 and the ground.

Note that the current of transistor 4 is the same as that of transistor 3.
It is made larger than the current.

Furthermore, the hot side of the capacitor 31 is connected to the base of the transistor 5 for level determination, the transistors 5 and 6 are differentially connected, and the collector of the transistor 22 is connected to the terminal 13 through the resistor 22.

The collector of the disconnected transistor 5 is connected to the base of the transistor 6 through the emitsume follower transistor 8 for changing the threshold level, and the base is connected to the connection point between the diode 41 and the transistor 4 through the emitsume follower transistor 9. be done.

Further, the collector of the transistor 5 is connected to the output terminal 12 through a transistor 10 whose terminal is grounded.

Note that 7 is a transistor for a constant current source.

According to such a configuration, as shown in FIG.
When pulse Pa rises to 1, transistor 1 turns on, and the collector current of transistor 3 becomes
The charge in the capacitor 31 is discharged through the transistor 1 while flowing to the transistor 1 .

In this case, since the base voltage of the transistor 2 is the reference voltage V, the emitter voltage of the transistor 1 is also approximately the reference voltage Vr.

Therefore, the terminal voltage of capacitor 31 is V. The voltage Vr decreases due to discharge, and this voltage ■.

The discharge stops and the voltage becomes V.

becomes the voltage Vr. In the octopus state, transistor 5
is off, transistor 6 is on, and therefore the collector voltage of transistor 5 is at a relatively high voltage, so that the base voltage of transistor 9 through transistor 8 is also at a relatively high voltage vu.

The emitter current of transistor 9 serves as the collector current of transistor 4.

In the past, when an octopus was used, the anode voltage of the diode 41 was a voltage (=Vr) due to the capacitor 31, and the cathode voltage was approximately the voltage vu due to the transistor 9, so the diode 41 was reverse biased and turned off.

Furthermore, since transistor 5 is off, transistor 1
0 is also off, so the output pulse pb is falling.

Then, when the pulse Pa falls during the period t2, the transistor 1 is turned off, and the capacitor 31 is turned off by the transistor! ! The collector current of X3, that is, the capacitor 31 is charged with a constant current, and the voltage Vc of the capacitor 31 increases at a constant rate during period t2.

Also at this time, the base 1i pressure of the transistor 5 (=V
, ) is lower than the base voltage (=Vu) of the transistor 6, the transistor 5 is off and the transistor 6 is on. Therefore, as in the period t1, the diode 41 is off and the pulse pb falls. There is.

Then, in the period t3, the voltage of the capacitor 31 is V.

becomes the voltage vu, so the transistor 5 turns on and the transistor 5 turns off, and the collector voltage of the transistor 5 decreases, so the emitter voltage of the transistor 8, that is, the base voltage of the transistor 9, becomes the voltage V.
d.

Therefore, the anode voltage of diode 41 is
1 becomes the voltage VC (2 VU), and the cathode voltage becomes approximately the voltage Vd due to the transistor 9, so the diode 41 is forward biased and turned on, and the charge in the capacitor 31 is discharged through the diode 41 and the transistor 4, The terminal voltage Vc decreases.

Note that in this case, the transistor 4 operates as a constant current source, so the voltage is ■.

decreases at a certain rate.

The collector current of the transistor 3, which has increased in size, also flows through the diode 41.
The current flows through the transistor 4 through the transistor 4.

Furthermore, at this time, since the transistor 5 is on, the transistor 10 is also on, and therefore the output pulse pb is rising.

Then, in the next period t4, the voltage V of the capacitor 31
.

becomes the voltage Vd, so transistor 5 is turned off and transistor 6 is turned on.

Therefore, the operating state is the same as that of period t2, and the capacitor 31
is charged again by the collector N current of transistor 3,
Voltage VC continues to rise.

Thereafter, such operations are repeated, and further for a period t7.
Then, the pulse Pa causes the operation after the period t1 to be repeated.

Thus, according to the present invention, when input pulse Pa is supplied, output pulse pb can be obtained after a predetermined period t2 from input pulse Pa.

Moreover, in that case, the slope of the voltage increase during period t2 is
Since it is always constant, by adjusting the variable resistor 21 and changing the value of the reference voltage Vr, the period t2 can be changed accordingly.

It is also easy to convert it into an IC.

[Brief explanation of the drawing]

FIG. 1 is a connection diagram of an example of the present invention, and FIG. 2 is a waveform diagram for explaining the same. 11 is an input terminal, and 12 is an output terminal.

Claims (1)

[Scope of utility model registration request] A charging/discharging capacitor, a switching element that discharges this capacitor in synchronization with an input pulse, a charging circuit that charges the capacitor with a constant current, a discrimination circuit that discriminates the voltage of the capacitor, and discrimination of this discrimination circuit. The discrimination level of this discrimination circuit is set to the first discrimination level t according to the output.
he has a discrimination level change circuit that changes to a second discrimination level lower than this, and a discharge circuit that discharges the capacitor with a constant current under the control of the output of this discrimination level change circuit, and Immediately after the supply, the capacitor is charged with a constant current, and when the voltage of the capacitor reaches the first discrimination level, the discrimination level is changed to the second discrimination level, and the discharge circuit is operated. When the capacitor is discharged with a constant current and the voltage of the capacitor reaches the second discrimination level,
While returning the discrimination level to the first discrimination level,
By charging the capacitor again with a constant current and repeating this charging operation until the next input pulse is supplied, an output pulse of a predetermined width is repeatedly generated with a delay of a certain period from the input pulse. Synchronous oscillation circuit.