SU1056458A1 - Bridge-type delay element - Google Patents

Description

The invention relates to a pulse technique that can be used in pulse devices of telemechanics, automation, measurement technology and is intended to form time-stable, delayed in time rectangular pulses.

Known bridge delay elements containing a bridge circuit, as well as an output transistor. The shoulders of the bridge are made of resistors and capacitors. A comparator is included in one of the bridge diagonals, for example, a diode. one of the shoulders of the bridge is connected in series with the control junction of the output transistor Щ.

These known delay elements have insufficient performance and are directly connected to the previous cascade, which is the trigger, which limits the functionality.

Closest to the proposed is the bridge delay element,. containing resistors in the three shoulders of the bridge, a chain of connected in series time of the driving capacitor and the control junction of the output transistor, in parallel to which a diode and a resistor are connected, in the fourth shoulder of the bridge, a diode in the internal diagonal of the bridge, and a potential bus and a common bus connected to the external diagonal .

The disadvantages of the bridge element are the long duration of the falling edge of the output pulse, which reduces the speed of the element; the dependence of the bridge element mode on the state of the preceding control cascade, which limits the functional capabilities of the bridge element.

i. The purpose of the invention is to increase speed and enhance functionality.

To achieve this goal, there is a bridge delay element containing resistors in the three arms of the bridge, a circuit consisting of a series-connected driver capacitor and a control junction of the output transistor, in parallel with which a diode and a resistor are connected, in the fourth bridge diode in the internal diagonal of the bridge, moreover, potential and common busbars are connected to the external diagonal, an additional transistor and a resistor are introduced,

the base of the additional transistor is connected via an additional resistor to the collector of the output transistor and the output of the element, and the collector-emitter section of the additional transistor is connected to the shoulder of the driving capacitor and the control transition of the output transistor.

The drawing shows a circuit diagram of the device.

The bridge delay element contains a bridge, the shoulders of which form resistors 1–3, the time setting capacitor 4, the control transition of the output transistor 5 to the internal diagonal of the bridge, diode 6 is turned on. Parallel to the control transition of the output transistor, a resistor 7 and diode 8 are connected. 5 is connected to the potential bus through a resistor 9 and to the output 10 of the element. An additional transistor 11 is connected to the bridge shoulder, parallel to the circuit from the time of the driving capacitor and the control junction of the output transistor 5, the base of which is connected to the collector of the output transistor 5 via an additional resistor 12. The time specifying the capacitor f is connected between the base of the output transistor 5

Bridge delay element running

in the following way.

,

In the initial state, the output transistor 5 and the diodes and 8 are closed, the transistor 11 is open until saturation. Therefore, the time setting the capacitor in the initial state is almost completely discharged, and the bridge element is ready for operation. Resistor 7 sets the initial zero potential to the base of the output transistor 5.

A positive voltage jump or a short positive pulse is applied to trigger the delay element to the control input (element input 13). Through the capacitor 1, a positive pulse arrives at the base of the output transistor 5 and opens it.

The resulting base current through the resistor and the base-emitter junction of transistor 5 charges the capacitor k. On the collector of transistor 5, the voltage abruptly decreases to zero, forming the leading edge of the output pulse

The transistor 11 is closed, the voltage on its collector increases, as the charge on capacitor i increases. .

When the voltage on the time of the master capacitor t reaches the reference voltage specified by the divider across resistors 2 and 3, the charging current is stopped and the transistor 5 closes, forming the falling edge of the output pulse. The transistor 11 opens and provides a fast discharge time to the reference capacitor, the resorption of minor base carriers and the reduction of the falling edge of the output pulse.

Compared with the known delay bridge element, an additional transistor is applied, connected in parallel with the time setting the capacitor and controlled from the output transistor, and the additional coupling capacitor of the control input of the element and the base of the output transistor. This provides a reduction in the back front of the output pulse and an increase in speed, as well as the independence of the operating mode of the bridge element from the previous cascade, which expands the functionality of the bridge delay element.

Claims (1)

A BRIDGE DELAY ELEMENT containing resistors in the three arms of the bridge, a circuit of a series-connected time-varying capacitor and a control transition of the output transistor, in parallel with which a diode and a resistor are connected, in the fourth arm of the bridge, the diode in the internal diagonal of the bridge, and the potential and a common bus, I distinguish it by the fact that, in order to improve performance and expand functionality, additional transistor and resistor are introduced into it, while the base is additional th transistor through a further resistor connected to the collector of the output transistor and the output member, and the collector-emitter section of the transistor included in the additional arm of the bridge consisting of the timing capacitor and the control transfer of the output transistor. n »SU _(I1 1056458 wherein the base of the additional transistor is connected via an additional resistor to the collector of the output transistor and the output of the element, and the collector-emitter section of the additional transistor is included in the bridge arm, which consists of a timing capacitor and a control transition of the output transistor. The drawing shows a circuit diagram of the device. The bridge delay element contains a bridge, whose shoulders form! connected to a potential bus through a resistor 9 and to the output 10 of the element. An additional transistor 11 is included in the shoulder of the bridge, parallel to the circuit from the timing capacitor and the control transition of the output transistor 5, the base of which is connected to the collector of the output transistor 5 through an additional resistor 12. A timing capacitor 14 is connected between the base of the output transistor 5 and the input 13 of the element. The bridge delay element operates as follows. In the initial state, the output transistor 5 and the diodes 6 and 8 are closed, the transistor 11 is open until saturated <Therefore, the time-setting capacitor 4 in the initial state is almost completely discharged, and the bridge element is ready for operation. The resistor 7 sets the initial zero potential to the base of the output transistor 5 · ·, To start the delay element, a positive voltage jump or a short positive pulse is applied to the control input (input 13 of the element). Through the capacitor 14, a positive pulse arrives at the base of the output transistor 5 and opens it. 1 1056458