SU1356161A1 - Inverter with pulse/frequency control - Google Patents

Abstract

The invention relates to a pulse technique and can be used in power supply devices, automation, remote control and measurement technology. The aim of the invention is to increase reliability. The device contains two series-connected shunted resistors 3, 4 and thyristors 1, 2 controlled by photodinistors 5, 6 optocouplers connected to a common point of thyristors 1, 2 via a capacitor 11 connected to the common point of the output transformer 12 9, 10, light diodes 7, 8 of optocouplers excited, respectively, when charging and discharging the aforementioned capacitor. 1 il. i (L A 75 G ate O5 O5.

Description

The invention relates to a pulse technique and can be used in power supply and automation devices. Telemechanics and measuring equipment.

The purpose of the invention is to increase reliability.

The drawing shows a diagram of the device.

The inverter contains two series-connected thyristors 1 and 2, shunted by resistors 3 and 4, and the thyristor control circuit is turned on.

K- Nagr P K.J S

photodinistors 5 and 6, optocouplers, light-5 D transformation ratio;

Diodes 7 and 8 of which are connected anti-parallel and are shunted by anti-parallel connected stabilizers 9 and 10, Capacitor 11 is connected in series with output 20 transformer 12, the secondary winding 13 is connected to the secondary winding. Key 15 is connected to power supply 14.

The principle of operation of the device is 25.

Knagr- load resistance; R - resistance at short circuit in the secondary winding.

The duration t of the charge of the capacitor 11 to the voltage U across the primary winding of the output transformer 12, the stabistors 9 and the thyristor is equal to

t (R

,, + P Я “GR + K.

+ R ,,,,) .C-.

It is as follows.

After closing the key 15 from the power source 14 through the primary winding of the output transformer 12,. the resistor 3 and the LED 7 begin charging the capacitor 11, this turns on the photo diode 5 of the optocoupler and the thyristor 1. The charging current of the capacitor 11 increases hundreds of times, however the LED 7 is not disabled, since almost all the current passes through the stabistors 9,

When the capacitor 11 is charged to a voltage almost equal to the voltage of the power source, the thyristor 1 turns OFF. The polarity of voltage on stabors 9 and 10 is reversed. Now it will be detected by the discharge current of the capacitor 11 through the resistor 4. The LED 8 is turned on, which causes the photodiode 6 of the second optocoupler and the second thyristor 2 to turn on.

Capacitor I1 discharge through

primary winding output transformer

Matora 12, through stabilizers 10 and thyristor 2,

After that, a second cycle of oscillations will start in the order described.

The efficiency of the converter can be determined by

 itramsf itrynsf + ithir + istrv

(one)

Tr (.to5 are respectively effective voltage values at the output transformer (primary winding), thyristor, stabistor; 1 trans efficiency of the transformer.

Automatic control of the mode of operation of the scheme is obtained as follows.

The resistance in the depy of the primary winding of the output transformer (if we neglect the losses) can be represented as

K- Nagr P K.J S

(2)

D transformation ratio;

Knagr- load resistance; R - resistance at short circuit in the secondary winding.

The duration t of the charge of the capacitor 11 to the voltage U through the primary winding of the output transformer 12, the stabilizers 9 and the thyristor 1 is equal to

five

t (R

0

 shooting gallery

0

,, + P Я “GR + K.

IR

+ R ,,,,) .C-.,

(3) where and is the voltage of the power source;

C - capacitor capacitance 11; R, K - effective values of thyristor and stabilizer resistances.

When the KNOGR decreases, the load current increases) the output voltage 5 remains almost unchanged, as t decreases and the oscillation period decreases

. T t, + tj, (4)

where tj is the duration of capacitor discharge 11.

A decrease in period T is equivalent to an increase in the frequency of oscillations f.

The power transmitted to the load (if you do not take into account losses) is equal to

si

five

 J, f 2

(five)

The increase in the power transferred to the load leads to the support at a constant level of the output eg.

An inverter with a frequency-pulse 55 control, containing two series-connected thyristors connected to the input terminals with a control unit, as well as a serial number 1313561614 connected to one of the input terminals

a primary circuit from the primary winding by the inserted resistors, and the light transformer and the capacitor, the high voltage diodes of the optocouplers are switched on by the fact that, in parallel between the connection point

In order to increase reliability, the up-thyristor unit and the mentioned sequence are made in the form of a photodinis-tial circuit and the anhars of the optocouplers are switched on, which are included in the control of the included thyristor-terminated circuits.

Claims (1)

Claim An inverter with pulse-frequency regulation, containing two thyristors connected in series to the input terminals with a control unit, as well as a sequential chain connected to one of the input terminals from the primary winding of the output transformer and capacitor, characterized in that, in order to increase reliability, the unit the control is made in the form of photodinistors of 5 optocouplers included in the control circuit of thyristors, shunted by the introduced resistors, and the optical diodes of the optocouplers included allelic between the connection point of the thyristors and said serial chain and similarly shunted included imposed Zener diode.