SU1413730A1 - Sawtooth current generator - Google Patents

Abstract

The invention relates to a pulse technique and can be used in the construction of sweepers in television measuring and radar equipment. The aim of the invention is to reduce the magnitude of the supply voltage. The generator contains a key element I double-sided conductivity, clock signal 2, current source 3, capacitor 4, power supply bus 5, inductive load 6, bipolar circuit 7. Key element 1 is executed on transistors 8 and 9, register 10, diode I-I. A bipolar circuit consists of transistors I2 and 13, a capacitor 14, a potentiometer 15, a resistor 16. Source 3 is made up of a transistor 17, a diode I8, resistors 19 and 20, and a source 2 voltage. The use of this generator in small-sized cameras of television devices will simplify the design of cameras and improve their weight and size characteristics, 2 Il. with S (L

Description

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The invention relates to a pulse technique and can be used in the construction of sweepers.

The aim of the invention is to reduce the supply voltage.

Figure 1 shows the circuit diagram of the device; 2 shows diagrams for his work.

The piped current generator contains a key element 1 of double-sided conductivity, the control terminal is connected to the sync signal bus 2, the current source 3, the first output of which is connected to the common bus of the device, the second output from the first condenser 4, the bus 5 power supply, inductive load 6, bipolar circuit 7, the first terminal of which is connected to the output of key Mementa 1 bilateral conductivity, whose cable is connected to bus 5 of the power supply, the second terminal of the double-sided circuit 7 tive load 6 and the first plate of the capacitor A, the second lining of which and the second output of the inductive load b are connected to the common bus of the device.

The key element 1 is made on transistors 8 and 9, a resistor 10, a diode 11, a bipolar circuit on transistors 12 and 13, a capacitor 1A, a potentiometer 15, a resistor 16.

The current source 3 is made on a transistor 17, a diode 18, resistors 19 and 20, and a voltage source 21.

The device works as follows.

The clock signals supplied to the control input of the key Element 1 of double-sided conductivity (Fig. 2a) put the element 1 into the conducting state during the forward sweep stroke, and a source of power is applied to the inductive load 6 via a two-pole circuit 7

 (shsh 5). Since a slightly pulsating voltage (r.2, b) forms on the capacitor 14 entering the circuit 7 during the first few sweep periods after switching on the device, the source voltage does not apply directly to the inductive load 6, and the difference between the voltage of the power source and the voltage formed on the capacitor 14 (Fig. 2c). Under

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by the difference of these voltages, the current in the inductive load 6 changes according to a law close to linear (Fig. 2d): first decreases to zero and then, changing the direction to the opposite, begins to increase. During the forward stroke of the sweep in an inductive load, a current flows (Fig. 2, e), the Pasteur # 1 is a current source 3 (the short-circuit of the current to the power source is prevented by the bipolar circuit 7) in the direction opposite to the constant component of the sawtooth current, and thus compensates for the effect of the latter; for this reason, the current in the inductive load does not contain a constant component (Fig. 2, d).

During the reverse sweep, the sync pulses translate the key element of the two-sided conduction 1 into a non-conducting state, as a result of which the power supply (bus 5) is disconnected from the inductive load 6. The resulting oscillating circuit composed of inductive load b and capacitor 4 is provided with an oscillatory a process lasting slightly more than half the period of free oscillations. The current in the inductive load b changes according to the cosine law: first it decreases to zero, and then, changing the direction to the opposite, increases (Fig. 2, d). The voltage on the inductive element b varies according to a sinusoidal law: it reaches its maximum value (in absolute value) in the middle of the reverse sweep stroke (Fig. 2c). I

In the case of a key element of bilateral conduction 1 in the form of a transistor 9, a diode 11 and a key transistor 8, it works in the following way.

If there is no unlocking voltage at the junction of the base-emitter of the key transistor 8, this transistor is locked. Locked and transistor 9, since there is no current in the circuit of its base. When unlocked at the input of the key transistor 8, the upper (according to the circuit of Fig. 1) output of the resistor 10 will be connected to the housing and in the emitter series circuit. - the collector of the key transistor 8 resistor 10, the base - emitter of transistor 9 and the power supply (bus 5) flow current, tran3,

the resistor 9 is unlocked and allows current to flow in its output circuit. Due to diode 11, the current in this circuit will flow in both directions.

When performing a bipolar circuit 7 on the regulating 13 and adjustable 12 transistors, it works as follows.

The control transistor 13 is unlocked at the input by the voltage supplied to its base from the potentiometer 15, therefore, after transferring to the conductive state of the key element 1, two-sided conduction and supplying the voltage of the power source to the emitter, the adjustable transistor 12 also passes in unlocked state. As a result, such a circuit is created for the flow of a constant component of an inductive load current 6: a power source that is in a conducting state is a key element of two-sided conduction, an emitter-collector gap of the adjustable transistor 12, an inductive load of load 6, closes to the capacitor 14. When the voltage at the input of the regulating transistor 13 is changed by means of potentiometer 15, the collector current of this transistor is changed, equal to the base current of the adjustable transistor 12, consequently, the voltage drop across the emitter-collector gap of the latter and the capacitor 14. Since this changes the voltage directly applied to the inductive load 6 (Fig. 2b), the span of the sawtooth current also changes, since the latter is directly proportional to the voltage applied to the inductive load 6 during the forward sweep stroke. Thus, using the potentiometer 15, the sweep of the sawtooth current can be adjusted.

In the case of the implementation of the source 3 current transistor 17 and the diode I8, it works as follows.

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The collector current of the transistor 17, and hence the current of source 3 (fig. 2e) is set by the base current of this transistor using an alternating resistor 19. The diode 18 included in the collector circuit of transistor 17 is locked during the reverse of the voltage sweep on the inductive

load 6 and interrupts the flow of the collector current of the transistor 17 in this sweep period. As a result, the latch of the diode 18 is prevented from moving forward in the forward direction.

stroke collector - the base of the transistor 17 with the specified voltage and the output of this transistor is out of order.

The use of a sawtooth generator in building a sweep of devices on a row for small transmitting television cameras and small television water detectors will prevent the use of a separate high-voltage power source in the power supply circuit that complicates the camera and worsens its weight and size characteristics.

Claims (1)

Invention Formula A sawtooth current generator containing a key element of bilateral conduction, the control input of which is connected to the clock signal bus, the current source whose first terminal is connected to the common bus, the generator, the second terminal to the first capacitor plate, power supply bus, inductive load, different that, in order to reduce the magnitude of the supply voltage, a bipolar circuit was introduced into it, the first terminal of which is connected to the output of a key double-sided conductivity element whose input is connected to the source bus ika supply, a second terminal dvuhpo: Tosna circuit connected to the first terminal of the inductive load and obkleyte adkoy first capacitor, the second liner and which vtoroy.vuvod inductive loads are connected to a common: generator bus. I I I ia s ( , v phases. 2