CS213913B1 - Source of rectangular pulses having constant current amplitude without unidirectional component - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a rectangular pulse source of constant current amplitude without a unidirectional component to a measuring load at a constant voltage of the power supply. It solves the electrical wiring of the output circuit of the pulse source, where the circuit is controlled by pulses of a predetermined sequence and a match.

Hitherto known sources constant pulse current amplitude without the DC component are used at the outlet transoformátor or a condenser to separate the DC component and an increased total voltage of the pulses, because the stabilization of the flow checks to see size ^L while the resistance in series with the load. In this way, large losses are incurred and small dimensions and weights cannot be achieved with higher demands on the shape of the rectangular pulses and on the stability of the current under load.

These drawbacks are eliminated by the rectangular pulse source of constant current amplitude without the unidirectional component according to the invention, which is characterized in that the first pause velocity input terminal is connected through the pause capacitor, pause resistance and pause transistor emitter-base transition to ground. An opposite oriented pulse diode is connected in parallel to the pause transistor. The grounding pole is connected through the base of the pulse transistor base, through the pulse resistance and the pulse capacitor to the other pulse velocity input terminal. An opposite oriented pause diode is connected in parallel to the pulse transistor. The collector of the pause transistor is connected both to the load and to the collector of the switching pulse transistor. The collector of the pulse transistor is connected both to the load and to the collector of the pause switching transistor. The third input terminal is

213913 2 coupled via the base-emitter of the pulse switching transistor to a source that is coupled through the emitter-base transition of the pause switching transistor to the fourth input terminal.

By connecting the output circuit of the pulse source, a better mutual ratio between the current stability and the shape of the rectangular pulses on the one hand and the energy consumption, dimensions and weight on the other hand is achieved.

The attached drawing shows the connection of a constant current amplitude rectangular current source without DC component using two NPN-type transistors in the branches and two switching transistors of the PNP type. In the diagram of FIG. 1, the first pause branch input terminal 16 is coupled via a pause capacitor 14, a pause resistor 13, and a pause emitter-base transistor 11 to ground terminal 2. A parallel opposite oriented pulse diode 12 is coupled to the pause transistor 11. The ground pole 2 is connected via the base-emitter transition of the pulse transistor 2, the pulse resistance J and the pulse capacitor 2 at the second input terminal 6.

An opposite oriented pause diode 2 is connected in parallel to the pulse transistor 2. The collector of the pause transistor 12 is connected both to the load 20 and to the collector of the switching pulse transistor 5. The collector of the pulse transistor 2 is also connected to the load 20 and also to the collector of the pause switching transistor 15. The third input terminal 8 is connected via the base-emitter transition of the pulse switching transistor to the source 10. This source 10 is still connected via the emitter-base transition of the switching transistor 15 to the fourth input terminal 2. ·

The function of the pulse source of the invention is as follows. The pulses of the supply voltage magnitude and the predetermined sequence and width are simultaneously processed in two branches - the pulse branch and the pause branch. If the unidirectional component of the pulse current flowing through the load is to be removed, the capacitors / capacitances and resistances in both branches must be the same. The capacitors separate the unidirectional component from the pulse voltage and the resistors serve to adjust the required current magnitude by the load. In the pulse branch, only the resulting current of one polarity is stabilized during the pulse duration and the opposite polarity of the voltage is shortened by a 2-pause diode at the pause time. To stabilize the current, a high output resistance of the transistor in common base connection is used. Similarly, in the pause branch, the polarity voltage pulse diode 12 is shorted for the duration of the pulse and the reverse polarity current is stabilized by the pause transistor 11 in common base engagement, for the duration of the pause. Both stabilized components of the pulse current of opposite polarities are added together by the use of two switching transistors operating alternately, one in pulse and the other in pause,

The rectangular pulse source of the invention can be used to electrically stimulate living tissues, namely, nerve structures through stimulation electrodes, where it is unacceptable for the electrode polarization to have a mean load current different from zero. Because of the varying load resistance, it is also necessary that the total current be stabilized.

Claims (1)

A source of rectangular, constant current amplitude pulses without DC component for non-constant load, characterized in that the first pause branch input terminal (16) is coupled through the pause resistor (14) pause resistor (13) and the pause emitter-base transistor (11). parallel to the opposite poled diode (12) of the pulse to the ground pole (7), which is connected via a base-emitter transistor (1) pulse coupled parallel to the opposite oriented diode (2) of the pause, through a resistor (3) pulse and capacitor (4) the pulse transistor collector (11) is connected to the load (20) and the collector of the pulse switching transistor (5) and the collector of the pulse transistor (1) is connected to the load (1) 2) and on the one hand with the collector of the pause switching transistor (15) and another third input terminal (8) is connected via the base-emitter switch of the pulse switching transistor (5) to the source (10) which it is connected via the emitter-base transition of the switching transistor (15) to the fourth input terminal (9).