SU1517117A1 - Amplification device - Google Patents

Abstract

The invention relates to amplifier technology. The purpose of the invention is to expand the dynamic range by reducing the deadband and reducing power loss. The amplifying device comprises a power amplifier 1 consisting of a preliminary stage 5 amplification, a push-pull amplification output stage 6 and resistors 10 and 11, a pulse amplifier 2, comparators 3 and 4, low-pass filters 7 and 8, load 12, resistors 13 and 14, a two-pole comparator 15 and adjustable resistors 16 and 17. The input signal is amplified by a cascade 5, the load of which is a resistor 10/11 /, a base-emitter junction in the forward bias of transistor 18/19 / and a load resistance 12. Feedback signal, middle divider, s the rest of the transistor 18/19 / and the load 12 decreases by a predetermined number of times. This is equivalent to an increase in coefficient. amplification of the cascade 5 in the same time compared with the coefficient. amplification of the amplifier 1. But the signal supplied to the load remains the same as when the amplifier 1 is operating with the power of the transistors 18/19 /, since the signal of the cascade 5 is divided by the same number of times. The same zone decreases insensitivity. 2 Il.

Description

20

cl

g

SP

Power 1, consisting of pre-amplification stage 5, push-pull amplification output stage 6 and resistors 10 and 11, pulse ih ;; i amplifier 2, comparators 3 and 4, low-pass filters 7 and 8, load 12, resistors 13 and 14, a two-pole p-iiMi i comparator 15 and adjustable resistors 16 and 17o. The input signal is amplified by a cascade 5, the load of which is resistor 10 (11), the base-emitter junction in the forward bias of transistor 18 (19) and load resistance 12 Feedback signal.

the mid-point splitter consisting of the transistor 18 (19) and the load 12 decreases by a predetermined number of times. This is equivalent to increasing the gain of the cascade 5 at the same time as the gain of amplifier 1. But the signal supplied to the load remains the same as when amplifier 1 is powered by transistors 18 (19), as the signal cascade 5 for the same number of times. The same zone decreases insensitivity. 2 or about

The invention relates to elements of an automatic control system; i can be used when creating automatic devices for automatic systems 1: - control with a wide range of combustion-esti on the basis of contactless motors.

The purpose of the invention is to expand the diagnostic range by reducing 1:; in dead zones and reducing losses.

The figo presents the principles of the aptics circuit of the amplifying device; FIG. 2 shows the time diagram of the operation of the amplifying device.

Amplifier contains power amplifier 1, pulse amplifier 2, first 3 and second 4 comparators, preliminary stage 5 amplifiers, push-pull amplification output stage 6, first 7 and second 8 AI filters, frequency feedback circuit 9 , first 10 and second 11 resistors, load 12, first 13 and second 14 additional resistors, dual comparator 15, first 16 and second 17 adjustable resistors, n1 and ETH dyukhtaktny output tspskad amplification performed on trans.T.ipax 18 and 19 , power supply 20 with ciiejiHeH point, resistor 21

The device works as follows.

When there is no input signal

a two-pole comparator 15 generates a signal C of FIG. 2, b of negative polarity, equal to -U, and U. b,. „, Lg. 1-0.5 V, where UK.5. „As

35

25

- Q s d

50

55

the minimum value of the transistors 18 and 19 of the push-pull output stage 6 of the amplifier. The signal -U is fed through the appropriate resistor to the non-inverting (inverting) input of the comparator 3 (4), the output of which is set to a negative potential, which will cover the transistors of the corresponding pulse of the pulse amplifier 2 and the collector voltage of transistor 18 (19) will be zero until the two-pole comparator 15 changes the polarity of the output signal. Figure 2, and shows the input signal of the device, where and, is the level of the two-polar comparator 15.

When the input signal is greater than U, where and, is the response threshold of the two-pole comparator 15, with U n and U; - the magnitude of the dead zone of the push-pull output amplification stage 6, reduced to the input signal, at the output of the two-pole KONT-parator 15, a positive potential U is set, which sets the positive (negative) potential at the output of comparator 3 (FIG. 2, g), which opens the transistors of the other side of the pulse amplifier 2. The voltage of the positive (negative) power supply 20 + E (-E) through the open transistor of the pulse amplifier 2, filter 7 (8) goes to the collector of transistor 18 (19) and to the inverter yuschy comparator input 3 (4). If this signal is larger than the resulting signal coming to

515

non-inverting input of comparator 3 (4) (Fig. 2, e), consisting of a signal (Fig. 2, d) from the emitter of transistor 18 (19), coming through resistor 13 (1A), signal from the output of the amplifying device (from the emitter transistor 18 (19) entering through the adjustable resistor 16 (17) and the signal Ug coming from the output of the two-polar comparator 15, the comparator will change the polarity of the output signal (figure 2, g) to negative and close the transistors the corresponding shoulder of the pulse amplifier 2. With increasing the above resulting signal comparator 3 (4) again changes the field polarity of the output signal and opens his shoulder transistors sootvetstvuyup pulse amplifier 2

Thus, the pulse amplifier 2 generates a signal (FIG. 2, c), exceeding the emitter signal of transistor 18 (19), by the sum of the signal U ;, and the signal coming from the output of power amplifier 1, through an adjustable resistor 16 (17), thus performing the following power supply for transistor 18 (19).

In this case, the signal UQ serves either to turn off the pulse amplifier 2 or to create a reference voltage that determines the switching threshold of the pulse amplifier.

The signal from the output of power amplifier 1 through adjustable resistor 16 (17) serves to proportionally increase the collector-emitter voltage of transistor 18 (Fig. 2, e), with an increase in output voltage (current) of power amplifier 1, which allows consider the dependence of the saturation voltage on the load current. The adjustable resistors 16 (17) are adjusted so that at maximum output voltage (current of power amplifier 1, the collector-emitter voltage of transistor 18 (1 9) is slightly higher than the collector-emitter voltage of transistor 18 (19).

In this case, the collector-emitter voltage of transistor 18 (19) will be slightly more than the collector-emitter saturation voltage and will vary with the output voltage of the amplifying device. In figure 2, d the dotted line shows the tension 176

a collector - emitter of a known transistor. A change in the collector-emitter voltage of the transistors with a change in the output voltage of the amplifying device makes it possible to reduce the thermal power emitted by the transistors, as compared with the known one, by a factor of 1.5–2.

device output.

The power supply of the preliminary cascade 5 amplification is carried out from the power source 20.

Power amplifier 1 works with.

the gain K / j determined by the resistor 21.

When the input signal of the amplifying device is O 1 and 1 Ü lU, (the voltage on the collector of transistor 18 (19) is zero (FIG. 2, c)) In this case, the input signal Ugj is amplified by the preliminary cascade 5 gains The preamplifier load in this case is resistor 10 ( 11), the base-emitter junction in the forward bias of the transistor 18 (19) and the load resistance 12. The feedback signal taken from the midpoint of the divider from the transistor 18 (19) and the load 12

(the base-emitter resistance of the transistor 18 in the open state can be neglected by comparison with the resistor 10 (II) and the load 12),

R o / R 1 decreases in p-TTJ- (R-TT ;-) rae,

. 10 u К „+ К.2.

which is equivalent to an increase in the gain of the preliminary amplification cascade by the same factor as in Kue. But the signal supplied to the load remains the same as when the amplifier 1 is powered with transistors 18 (19), as the signal of the preliminary stage of the amplification in

R / R 1 T1

-1B B. In the same

 10 1 N2.

the dead zone is reduced as well.

formula of invention

The amplifying device, containing the power amplifier, is made in the preliminary and two-stroke amplification stages, while the power outputs of the preliminary amplification stage are connected directly to the corresponding mid-point power supply buses, the two-stroke amplification output stage is made on transistors, the emitters of which are combined and connected to the load and to the input of the feedback circuit for voltage, the output of which is connected to one of the inputs of the preliminary cascade of amplification, the other input of which is The device input, the collectors of the transistors of each arm of the push-pull amplification output stage are connected via the first and second comparators to the inputs of the pulse amplifier, respectively, and through the first and second low-pass filters to the outputs of the pulse amplifier, respectively, the power terminals of which are connected to the corresponding power supply buses. with a midpoint, with the reference inputs of the first and second comparators

The first and second resistors are respectively connected to the load, characterized in that, in order to expand the dynamic range by reducing the deadband and reducing the power loss, the first and second additional amplifiers are connected between the output of each arm of the preliminary amplification stage and the input of each arm of the two-stroke output amplification stage. resistors, respectively, and between the input of the preliminary cascade of amplification and the corresponding reference inputs of the first and second comparators introduced two-pole The first comparator, while between the reference inputs of the first and second comparators and the load included the first and second adjustable resistors, respectively.

Fie.2

Claims (1)

Claim An amplifier device containing a power amplifier made on a preliminary and push-pull output amplification cascades, while the power output terminals of the preliminary amplification cascade are connected directly to the corresponding busbars of the power supply with a midpoint, the two -7-output amplification cascade is made on transistors, the emitters of which are combined and connected to the load and to the input of the voltage feedback circuit, the output of which is connected to one of the inputs of the preliminary amplification stage, the other input of which is is the input of the device, the transistor collectors of each arm of the push-pull output amplifier stage are connected through the first and second comparators to the inputs of the pulse amplifier, respectively, and through the first and second lower filters through the first and second resistors, respectively, connected to the load, characterized in that, in order to expand the dynamic range by reducing the deadband and reducing power loss, between the output of each arm of the preliminary 1Q amplification stage and the input of each arm is push-pull of the output amplification stage, the first and second additional resistors are included, respectively, and between the input of the preliminary amplification stage and the corresponding reference frequencies, with the outputs of the pulse amplifier, respectively, the power leads of which are connected to the corresponding power source buses with a midpoint, and the reference inputs of the first and second comparators the inputs of the first and second comparators introduced a bipolar comparator, while between the reference inputs of the first and second comparators and the load s first and second adjustable resistors respectively.