SU653733A1 - Pulse generator - Google Patents

Description

CONTROL CHAIN - providing independent control of duty ratio.

To do this, a pulse generator containing an operational amplifier whose direct output is connected to the output of the master circuit, an inverting input is connected to the output of a resistive divider, whose inputs are connected between the power source and the common bus, the first switch whose output is connected to the output of the drive circuit and the control input is connected to the output of the operational amplifier and to the counting input of the trigger, the outputs of which are connected to the inputs of two OR elements, and the second key, one of which is connected to the output of the resistive The solver, and the control one, is connected to the output of the first element OR, a third key is added, one pin of which is connected to the second end of the second key and an additional controlled output of the resistive depiteld, the second pin is connected to the common bus, and the control input is connected to the output of the second element OR, the second input of which is connected to the second input of the first alemvite OR and to the output of the operational amplifier.

The drawing shows the principal electrical scheme of the proposed pulse generator.

The pulse generator contains an operational amplifier 1, a straight line, whose input is connected to the output of the time of the driving circuit 2 from resistor 3 and capacitor 4, and the inverting input to the output of a resistive voltage divider 5 from a fixed resistor b and a controlled resistive divider 7, inputs which are connected between the power supply and the common bus. The output time of the driver circuit 2 is connected to the first key 8, the control input of which is connected to the output of the operational amplifier 1. Between the outputs of the resistive divider 5, the second key 9, and between the controlled output and the busbar - the third key 10, the control inputs of which connected to the outputs of the elements OR 11 and 12, the first inputs connected to the outputs of the trigger 13, and the second 1 and the inputs to the output of the operational amplifier 1 and to the counting input of the trigger 13

The generator works in a special way.

When connecting p tayushvk sources on the inverted input of the operating

the amplifier 1 is set to a positive potential higher than at the direct input, as a voltage can be applied to this input, the minimum value of which is equal to the sum of the two residuals on the keys 9 and 1O connected in series. At the output of the operational amplifier, the voltage is set to turn off the switches 8 and 9 or 10, depending on the state of the trigger 13.

Suppose that at the unit output of the flip-flop 13, at the moment of switching on the power supply sources, a level is set corresponding to zero. Then, at the output of the OR 11 signal, a signal appears, including the key 9. And at the output of the OR 12 element, a signal appears that turns off the key 1O. Then, at the output of the divider 5, a voltage is set corresponding to the division factor of the divider from resistor 6 and part of resistive divider 7, equal to

2 and „„ Е

op

R.Kj

where I / is the resistance of the resistor 6; T 2 is the resistance of a part of the resistive divider between the controlled output and the common bus.

Due to the fact that the switch shunt capacitor 4 is turned off, the capacitor starts to charge. When the voltage on the capacitor reaches the reference level, the voltage at the output of the operational amplifier 1 reverses sign. This leads to switching on the key 8 and the appearance at the output of the elements OR signals, including the keys 9 and 1 O, as a result of which the reference voltage on the inverting input of the operational amplifier 1 abruptly decreases to the sum of two residual voltages of the public keys, and the capacitor 4 begins to burst to this level The discharge time is longer than the transient when turning on keys 9 and 10. Therefore, between inputs; an operational amplifier creates a potential difference that facilitates faster device switching.

Claims (2)

When the voltage on the encoder reaches a low level of the reference voltage that is generated on the open keys 9 and 10 by the current flowing through the resistor 6, the voltage on the output of the operational amplifier changes sign, and the keys 8 and 9 turn off, and the key 10 remains on, since the previous switching of the signal at the output of the operational amplifier changed the state of the trigger 13, setting the output element OR 12 signal unit. This switching process is accompanied by a positive feedback due to the lag of the rising voltage on the capacitor from the rising reference voltage at the moment of switching. At the output of divider 5, it sets the voltage Uon; I, where Kg is the resistance of a part of resistive divider 7 between the controlled output of divider 5. Now capacitor 4 will charge to the second reference level, and when the voltage reaches this level on the capacitor at the output of the operational amplifier, it changes sign by opening the keys 8, 9 and 1О and tilting the trigger 13, and the unit signal from its output goes to the element OR 1 The capacitor starts discharging through the key 8 to a low reference level & n, and after switching the operational amplifier to another state, it is charged to the first reference level, ..., etc. A change in the reference voltages of a controlled resistive divider 7 leads to a change in the duty cycle over a wide range. The period of the generated pulses is equal to Ri (Ti. Assuming that R, 4j is -Rj-con9t), it can be concluded that changing the duty ratio has a slight effect on the value T. Invention The pulse generator containing an operational amplifier whose direct input connected to the vampaduct output of the circuit, the inverting input is connected to the output of the resistive divider, whose inputs are connected between the power source and the common bus, the first key, the output of which is connected to the output of the master circuit, and the control input is connected to the output of the operation Ion amplifier and with a counting trigger input, which is connected to the inputs of two OR elements, the second key, one output of which is connected to the output of the resistive divider, and the control input is connected to the output of the first OR element, characterized in that the third key, one output of which is connected to the second output of the second key and an additional controlled output of the cutting divider, the second output is connected to the common bus, and the control input is connected to (key to output the second element OR, the second input of which is connected to the second input of the first element OR and to the output of the operational amplifier. Sources of information taken into account in the examination 1. USSR author's certificate number 49484O, cl. N OZ 3 1 / O2, 1974. 2. USSR author's certificate number 413606, cl. H 03 K 3/335, 1972. .0y / lg J 653733  "Ml