Linear transformer TVS. Thermal parameters of the reactor, fuel assemblies and fuel rods. V. silchenko, s. Vikulovo, Tyumen region

The device in question generates electrical discharges with a voltage of about 30 kV, so please exercise extreme caution during assembly, installation and further use. Even after turning off the circuit, some voltage remains in the voltage multiplier.

Of course, this voltage is not fatal, but the switched on multiplier can pose a danger to your life. Follow all safety precautions.

Now let's get down to business. To obtain high-potential discharges, components from the line scan of a Soviet television were used. I wanted to create a simple and powerful high-voltage generator powered by a 220-volt network. Such a generator was needed for experiments that I carry out regularly. The generator power is quite high, at the output of the multiplier the discharges reach up to 5-7 cm,

To power the line transformer, LDS ballast was used, which was sold separately and cost $2.

This ballast is designed to power two fluorescent lamps, each 40 watts. For each channel, 4 wires come out of the board, two of which we will call “hot”, since it is through them that the high voltage flows to power the lamp. The remaining two wires are connected to each other by a capacitor, this is necessary to start the lamp. At the output of the ballast, a high voltage with a high frequency is generated, which must be applied to a line transformer. The voltage is supplied in series through a capacitor, otherwise the ballast will burn out in a few seconds.

We select a capacitor with a voltage of 100-1500 volts, a capacity from 1000 to 6800pF.
It is not recommended to turn on the generator for a long time, or you should install transistors on the heat sinks, since after 5 seconds of operation there is already an increase in temperature.

The line transformer was used type TVS-110PTs15, voltage multiplier UN9/27-1 3.

List of radioelements

Designation	Type	Denomination	Quantity	Note	Shop	My notepad
	Scheme of prepared ballast.
VT1, VT2	Bipolar transistor	FJP13007	2			To notepad
VDS1, VD1, VD2	Rectifier diode	1N4007	6			To notepad
C1, C2		10 µF 400 V	2			To notepad
C3, C4	Electrolytic capacitor	2.2 µF 50 V	2			To notepad
C5, C6	Capacitor	3300 pF 1000 V	2			To notepad
R1, R6	Resistor	10 ohm	2			To notepad
R2, R4	Resistor	510 kOhm	2			To notepad
R3, R5	Resistor	18 ohm	2			To notepad
	Inductor		4			To notepad
F1	Fuse	1 A	1			To notepad
	Additional elements.
C1	Capacitor	1000-6800 pF	1			To notepad
	Linear scan transformer	TVS-110PTs15	1			To notepad
	Voltage multiplier	UN 9/27-13	1

30 2 10 9 28 29 S 6 GTGTTTTT pttgt 15 U 18 16 22 20 23 21 19 13 12 26 27 7 8 Fig. &2S. Principal electrical diagram of line scan transformers type TVS-90PTs12 Transformers withstand the effects of: Vibration loads with acceleration, no more than 5g (49.1 m/s2) in the frequency range 1...80 Hz Repeated shock loads with acceleration, no more than 15 g ( 147.1 m/s2) impact duration, no more. . . 2...5 ms Increased temperature: for version UHL, no more... 55 ° C for version B and T, no more. . 70 ° C Overheating temperature of TVS-90PTs12 windings, no more than 45 ° C Low temperature: for group II application -25 ° C for group 1P application -10 ° C during transportation: for climatic version UHL -50 ° C for climatic version B or T -60 ° C Operating time of transformers in the modes and conditions specified above is ensured for 15,000 hours.

The failure rate during 15,000 hours of operation is 1.2* 10“® 1/h with a confidence level of 0.6.

Additional electrical parameters TVS-90PTs12 TVS supply voltage 285 V Pulse repetition frequency (15.6±2) kHz Beam return duration, with maximum deviations (12±1.5) μs Voltage at the output of the high-voltage rectifier, no more than 27.5 kV Load current of the high-voltage rectifier, no more than 1200 μA Rated voltage at the output of the high-voltage winding of the fuel assembly 128.5 kV Insulation resistance between the transformer windings, as well as between each winding and the magnetic circuit, no less than 10 MΩ Minimum value of the limiting voltage of alternating current with a frequency of 50 Hz 100 V, rms Winding insulation resistance at a relative humidity of 85% at a temperature of 35 °C, not less than 2 MOhm TVS signal output transformers for color TVs with picture tubes having a beam deflection angle of 110°. 10* 15 chickens Fig. &26. General view of advantageous line scan transformers such as TVS-110PTs15, TVS-110PTs16 PGPR pgtp 15 1^ 12 11 9 10 8 7 6 5 3 2 Fig. &27. Principal electrical data of horizontal scanning transformers of types TVS-110PTs15, TVS110PTs16 Signal output transformers of types TVS110PTs15 and TVS-110PTs16 are used in semiconductor output stages of horizontal scanning of color images with picture tubes of type 61LKZTs, having a beam deflection angle of 110°, and picture tubes with self-converging beams type 51LK2Ts. TVS-1YuPTs15 transformers operate in a set with a deflection system of type OS90.29PTs17, an output transistor of type KT838A, a damper diode of type B83G and a high-voltage rectifier-multiplier of type UN9/27-1.3. TVS110PTs16 transformers are used in conjunction with OS-90.38PTs12 and the same ERE components as TVS-110PTs15.

The general view and overall dimensions of the transformers are shown in Fig. 8.26. The electrical circuit diagram of the TVS-110PTs15 and TVS-110PTs16 transformers is shown in Fig. 8.27. Winding data of transformers are given in table. 8.8.

Output transformers are manufactured on rod-shaped U-shaped magnetic cores from a ferromagnetic alloy, the design and electromagnetic parameters of which are discussed in the second chapter of the reference book. Stable operation of transformers is ensured by climatic versions: UHL, V or T; categories 4.2; 3 or 1.1 according to GOST 15150-69 and application groups. Transformers of application group I in the UHL climatic version are manufactured in two types: with normal and increased moisture resistance. 291

High-voltage, low-power generators are widely used in flaw detection, to power portable charged particle accelerators, X-ray and cathode ray tubes, photomultiplier tubes, and ionizing radiation detectors. In addition, they are also used for electric pulse destruction of solids, production of ultrafine powders, synthesis of new materials, as spark leak detectors, for launching gas-discharge light sources, in electric-discharge diagnostics of materials and products, obtaining gas-discharge photographs using the S. D. Kirlian method , testing the quality of high-voltage insulation. In everyday life, such devices are used as power sources for electronic traps of ultrafine and radioactive dust, electronic ignition systems, for electroeffluvial chandeliers (chandeliers by A. L. Chizhevsky), aeroionizers, medical devices (D'Arsonval, franklization, ultratonotherapy devices ), gas lighters, electric fences, electric stun guns, etc.

Conventionally, we classify as high-voltage generators devices that generate voltages above 1 kV.

The high-voltage pulse generator using a resonant transformer (Fig. 11.1) is made according to the classical scheme using a gas spark gap RB-3.

Capacitor C2 is charged with a pulsating voltage through diode VD1 and resistor R1 to the breakdown voltage of the gas spark gap. As a result of breakdown of the gas gap of the spark gap, the capacitor is discharged onto the primary winding of the transformer, after which the process is repeated. As a result, damped high-voltage pulses with an amplitude of up to 3...20 kV are formed at the output of transformer T1.

To protect the output winding of the transformer from overvoltage, a spark gap made in the form of electrodes with an adjustable air gap is connected in parallel to it.

Rice. 11.1. Circuit of a high-voltage pulse generator using a gas spark gap.

Rice. 11.2. Circuit of a high-voltage pulse generator with voltage doubling.

Transformer T1 of the pulse generator (Fig. 11.1) is made on an open ferrite core M400NN-3 with a diameter of 8 and a length of 100 mm. The primary (low-voltage) winding of the transformer contains 20 turns of MGShV wire 0.75 mm with a winding pitch of 5...6 mm. The secondary winding contains 2400 turns of ordinary winding of PEV-2 wire 0.04 mm. The primary winding is wound over the secondary winding through a 2x0.05 mm polytetrafluoroethylene (fluoroplastic) gasket. The secondary winding of the transformer must be reliably isolated from the primary.

An embodiment of a high-voltage pulse generator using a resonant transformer is shown in Fig. 11.2. In this generator circuit there is galvanic isolation from the supply network. The mains voltage is supplied to the intermediate (step-up) transformer T1. The voltage removed from the secondary winding of the network transformer is supplied to a rectifier operating according to a voltage doubling circuit.

As a result of the operation of such a rectifier, a positive voltage appears on the upper plate of capacitor C2 relative to the neutral wire, equal to the square root of 2Uii, where Uii is the voltage on the secondary winding of the power transformer.

A corresponding voltage of the opposite sign is formed at capacitor C1. As a result, the voltage on the plates of the capacitor SZ will be equal to 2 square roots of 2Uii.

The charging rate of capacitors C1 and C2 (C1=C2) is determined by the value of resistance R1.

When the voltage on the plates of capacitor SZ is equal to the breakdown voltage of the gas gap FV1, a breakdown of its gas gap will occur, capacitor SZ and, accordingly, capacitors C1 and C2 will be discharged, and periodic damped oscillations will occur in the secondary winding of transformer T2. After discharging the capacitors and turning off the spark gap, the process of charging and subsequent discharging the capacitors to the primary winding of transformer 12 will be repeated again.

A high-voltage generator used to obtain photographs in a gas discharge, as well as to collect ultrafine and radioactive dust (Fig. 11.3) consists of a voltage doubler, a relaxation pulse generator and a step-up resonant transformer.

The voltage doubler is made using diodes VD1, VD2 and capacitors C1, C2. The charging chain is formed by capacitors C1 SZ and resistor R1. A 350 V gas spark gap is connected in parallel to capacitors C1 SZ with the primary winding of step-up transformer T1 connected in series.

As soon as the DC voltage level on capacitors C1 SZ exceeds the breakdown voltage of the spark gap, the capacitors are discharged through the winding of the step-up transformer and as a result a high-voltage pulse is formed. The circuit elements are selected so that the pulse formation frequency is about 1 Hz. Capacitor C4 is designed to protect the output terminal of the device from mains voltage.

Rice. 11.3. Circuit of a high voltage pulse generator using a gas spark gap or dinistors.

The output voltage of the device is entirely determined by the properties of the transformer used and can reach 15 kV. A high-voltage transformer with an output voltage of about 10 kV is made on a dielectric tube with an outer diameter of 8 and a length of 150 mm; a copper electrode with a diameter of 1.5 mm is located inside. The secondary winding contains 3...4 thousand turns of PELSHO 0.12 wire, wound turn to turn in 10...13 layers (winding width 70 mm) and impregnated with BF-2 glue with interlayer insulation made of polytetrafluoroethylene. The primary winding contains 20 turns of PEV 0.75 wire passed through a polyvinyl chloride cambric.

As such a transformer, you can also use a modified horizontal scan output transformer of a TV; transformers for electronic lighters, flash lamps, ignition coils, etc.

The R-350 gas discharger can be replaced by a switchable chain of dinistors of the KN102 type (Fig. 11.3, right), which will allow the output voltage to be changed stepwise. To evenly distribute the voltage across the dinistors, resistors of the same value with a resistance of 300...510 kOhm are connected in parallel to each of them.

A variant of the high-voltage generator circuit using a gas-filled device, a thyratron, as a threshold-switching element is shown in Fig. 11.4.

Rice. 11.4. Circuit of a high voltage pulse generator using a thyratron.

The mains voltage is rectified by diode VD1. The rectified voltage is smoothed by capacitor C1 and supplied to the charging circuit R1, C2. As soon as the voltage on capacitor C2 reaches the ignition voltage of thyratron VL1, it flashes. Capacitor C2 is discharged through the primary winding of transformer T1, the thyratron goes out, the capacitor begins to charge again, etc.

An automobile ignition coil is used as transformer T1.

Instead of the VL1 MTX-90 thyratron, you can turn on one or more KN102 type dinistors. The amplitude of the high voltage can be adjusted by the number of included dinistors.

The design of a high-voltage converter using a thyratron switch is described in the work. Note that other types of gas-filled devices can be used to discharge a capacitor.

More promising is the use of semiconductor switching devices in modern high-voltage generators. Their advantages are clearly expressed: high repeatability of parameters, lower cost and dimensions, high reliability.

Below we will consider high-voltage pulse generators using semiconductor switching devices (dinistors, thyristors, bipolar and field-effect transistors).

A completely equivalent, but low-current analogue of gas dischargers are dinistors.

In Fig. Figure 11.5 shows the electrical circuit of a generator made on dinistors. The structure of the generator is completely similar to those described earlier (Fig. 11.1, 11.4). The main difference is the replacement of the gas discharger with a chain of dinistors connected in series.

Rice. 11.5. Circuit of a high-voltage pulse generator using dinistors.

Rice. 11.6. Circuit of a high-voltage pulse generator with a bridge rectifier.

It should be noted that the efficiency of such an analogue and switched currents are noticeably lower than that of the prototype, however, dinistors are more affordable and more durable.

A somewhat complicated version of the high-voltage pulse generator is shown in Fig. 11.6. The mains voltage is supplied to a bridge rectifier using diodes VD1 VD4. The rectified voltage is smoothed out by capacitor C1. This capacitor generates a constant voltage of about 300 V, which is used to power a relaxation generator composed of elements R3, C2, VD5 and VD6. Its load is the primary winding of transformer T1. Pulses with an amplitude of approximately 5 kV and a repetition frequency of up to 800 Hz are removed from the secondary winding.

The chain of dinistors must be designed for a switching voltage of about 200 V. Here you can use dinistors of the KN102 or D228 type. It should be taken into account that the switching voltage of dinistors of type KN102A, D228A is 20 V; KN102B, D228B 28 V; KN102V, D228V 40 V; KN102G, D228G 56 V; KN102D, D228D 80 V; KN102E 75 V; KN102Zh, D228Zh 120 V; KN102I, D228I 150 V.

A modified line transformer from a black-and-white TV can be used as a T1 transformer in the above devices. Its high-voltage winding is left, the rest are removed and instead a low-voltage (primary) winding is wound 15...30 turns of PEV wire with a diameter of 0.5...0.8 mm.

When choosing the number of turns of the primary winding, the number of turns of the secondary winding should be taken into account. It is also necessary to keep in mind that the value of the output voltage of the high-voltage pulse generator depends to a greater extent on the adjustment of the transformer circuits to resonance rather than on the ratio of the number of turns of the windings.

The characteristics of some types of horizontal scanning television transformers are given in Table 11.1.

Table 11.1. Parameters of high-voltage windings of unified horizontal television transformers.

Transformer type	Number of turns		R windings, Ohm
TVS-A, TVS-B
TVS-110, TVS-110M

Transformer type	Number of turns		R windings, Ohm
TVS-90LTs2, TVS-90LTs2-1
TVS-110PTs15
TVS-110PTs16, TVS-110PTs18

Rice. 11.7. Electrical circuit of a high-voltage pulse generator.

In Fig. Figure 11.7 shows a diagram of a two-stage high-voltage pulse generator published on one of the sites, in which a thyristor is used as a switching element. In turn, a gas-discharge device neon lamp (chain HL1, HL2) was chosen as a threshold element that determines the repetition rate of high-voltage pulses and triggers the thyristor.

When supply voltage is applied, the pulse generator, made on the basis of transistor VT1 (2N2219A KT630G), produces a voltage of about 150 V. This voltage is rectified by diode VD1 and charges capacitor C2.

After the voltage on capacitor C2 exceeds the ignition voltage of neon lamps HL1, HL2, the capacitor will be discharged through the current-limiting resistor R2 to the control electrode of thyristor VS1, and the thyristor will be unlocked. The discharge current of capacitor C2 will create electrical oscillations in the primary winding of transformer T2.

The thyristor switching voltage can be adjusted by selecting neon lamps with different ignition voltages. You can change the thyristor turn-on voltage stepwise by switching the number of neon lamps connected in series (or dinistors replacing them).

Rice. 11.8. Diagram of electrical processes on the electrodes of semiconductor devices (to Fig. 11.7).

The voltage diagram at the base of transistor VT1 and at the anode of the thyristor is shown in Fig. 11.8. As follows from the presented diagrams, the blocking generator pulses have a duration of approximately 8 ms. Capacitor C2 is charged exponentially in accordance with the action of pulses taken from the secondary winding of transformer T1.

Pulses with a voltage of approximately 4.5 kV are formed at the output of the generator. The output transformer for low-frequency amplifiers is used as transformer T1. As

High-voltage transformer T2 uses a transformer from a photo flash or a recycled (see above) horizontal scanning television transformer.

The diagram of another version of the generator using a neon lamp as a threshold element is shown in Fig. 11.9.

Rice. 11.9. Electrical circuit of a generator with a threshold element on a neon lamp.

The relaxation generator in it is made on elements R1, VD1, C1, HL1, VS1. It operates at positive line voltage cycles, when capacitor C1 is charged to the switching voltage of the threshold element on the neon lamp HL1 and thyristor VS1. Diode VD2 dampens self-induction pulses of the primary winding of step-up transformer T1 and allows you to increase the output voltage of the generator. The output voltage reaches 9 kV. The neon lamp also serves as an indicator that the device is connected to the network.

The high-voltage transformer is wound on a piece of rod with a diameter of 8 and a length of 60 mm made of M400NN ferrite. First, a primary winding of 30 turns of PELSHO 0.38 wire is placed, and then a secondary winding of 5500 turns of PELSHO 0.05 or larger diameter is placed. Between the windings and every 800... 1000 turns of the secondary winding, an insulation layer of polyvinyl chloride insulating tape is laid.

In the generator, it is possible to introduce discrete multi-stage adjustment of the output voltage by switching neon lamps or dinistors in a series circuit (Fig. 11.10). In the first version, two stages of regulation are provided, in the second - up to ten or more (when using KN102A dinistors with a switching voltage of 20 V).

Rice. 11.10. Electrical circuit of the threshold element.

Rice. 11.11. Electrical circuit of a high voltage generator with a diode threshold element.

A simple high-voltage generator (Fig. 11.11) allows you to obtain output pulses with an amplitude of up to 10 kV.

The control element of the device switches with a frequency of 50 Hz (at one half-wave of the mains voltage). The diode VD1 D219A (D220, D223) operating under reverse bias in avalanche breakdown mode was used as a threshold element.

When the avalanche breakdown voltage at the semiconductor junction of the diode exceeds the avalanche breakdown voltage, the diode transitions to a conducting state. The voltage from the charged capacitor C2 is supplied to the control electrode of the thyristor VS1. After turning on the thyristor, capacitor C2 is discharged into the winding of transformer T1.

Transformer T1 does not have a core. It is made on a reel with a diameter of 8 mm from polymethyl methacrylate or polytetrachlorethylene and contains three spaced sections with a width of

9 mm. The step-up winding contains 3x1000 turns, wound with PET, PEV-2 0.12 mm wire. After winding, the winding must be soaked in paraffin. 2 x 3 layers of insulation are applied on top of the paraffin, after which the primary winding is wound with 3 x 10 turns of PEV-2 0.45 mm wire.

Thyristor VS1 can be replaced with another one for a voltage higher than 150 V. The avalanche diode can be replaced with a chain of dinistors (Fig. 11.10, 11.11 below).

The circuit of a low-power portable high-voltage pulse source with autonomous power supply from one galvanic element (Fig. 11.12) consists of two generators. The first is built on two low-power transistors, the second on a thyristor and a dinistor.

Rice. 11.12. Voltage generator circuit with low-voltage power supply and thyristor-dinistor key element.

A cascade of transistors of different conductivities converts low-voltage direct voltage into high-voltage pulsed voltage. The timing chain in this generator is the elements C1 and R1. When the power is turned on, transistor VT1 opens, and the voltage drop across its collector opens transistor VT2. Capacitor C1, charging through resistor R1, reduces the base current of transistor VT2 so much that transistor VT1 comes out of saturation, and this leads to the closing of VT2. The transistors will be closed until capacitor C1 is discharged through the primary winding of transformer T1.

The increased pulse voltage removed from the secondary winding of transformer T1 is rectified by diode VD1 and supplied to capacitor C2 of the second generator with thyristor VS1 and dinistor VD2. In every positive half-cycle

The storage capacitor C2 is charged to an amplitude voltage value equal to the switching voltage of the dinistor VD2, i.e. up to 56 V (nominal pulse unlocking voltage for dinistor type KN102G).

The transition of the dinistor to the open state affects the control circuit of the thyristor VS1, which in turn also opens. Capacitor C2 is discharged through the thyristor and the primary winding of transformer T2, after which the dinistor and thyristor close again and the next capacitor charge begins; the switching cycle is repeated.

Pulses with an amplitude of several kilovolts are removed from the secondary winding of transformer T2. The frequency of spark discharges is approximately 20 Hz, but it is much less than the frequency of the pulses taken from the secondary winding of transformer T1. This happens because capacitor C2 is charged to the dinistor switching voltage not in one, but in several positive half-cycles. The capacitance value of this capacitor determines the power and duration of the output discharge pulses. The average value of the discharge current that is safe for the dinistor and the control electrode of the thyristor is selected based on the capacitance of this capacitor and the magnitude of the pulse voltage supplying the cascade. To do this, the capacitance of capacitor C2 should be approximately 1 µF.

Transformer T1 is made on a ring ferrite magnetic core of type K10x6x5. It has 540 turns of PEV-2 0.1 wire with a grounded tap after the 20th turn. The beginning of its winding is connected to the transistor VT2, the end to the diode VD1. Transformer T2 is wound on a coil with a ferrite or permalloy core with a diameter of 10 mm and a length of 30 mm. A coil with an outer diameter of 30 mm and a width of 10 mm is wound with PEV-2 0.1 mm wire until the frame is completely filled. Before winding is completed, a grounded tap is made, and the last row of wire of 30...40 turns is wound turn to turn over an insulating layer of varnished cloth.

The T2 transformer must be impregnated with insulating varnish or BF-2 glue during winding, then thoroughly dried.

Instead of VT1 and VT2, you can use any low-power transistors capable of operating in pulse mode. Thyristor KU101E can be replaced with KU101G. Power source galvanic cells with a voltage of no more than 1.5 V, for example, 312, 314, 316, 326, 336, 343, 373, or nickel-cadmium disk batteries type D-0.26D, D-0.55S and so on.

A thyristor generator of high-voltage pulses with mains power is shown in Fig. 11.13.

Rice. 11.13. Electrical circuit of a high-voltage pulse generator with a capacitive energy storage device and a thyristor switch.

During the positive half-cycle of the mains voltage, capacitor C1 is charged through resistor R1, diode VD1 and the primary winding of transformer T1. Thyristor VS1 is closed in this case, since there is no current through its control electrode (the voltage drop across diode VD2 in the forward direction is small compared to the voltage required to open the thyristor).

During a negative half-cycle, diodes VD1 and VD2 close. A voltage drop is formed at the cathode of the thyristor relative to the control electrode (minus at the cathode, plus at the control electrode), a current appears in the control electrode circuit, and the thyristor opens. At this moment, capacitor C1 is discharged through the primary winding of the transformer. A high voltage pulse appears in the secondary winding. And so on every period of mains voltage.

At the output of the device, bipolar high-voltage pulses are formed (since damped oscillations occur when the capacitor is discharged in the primary winding circuit).

Resistor R1 can be composed of three parallel-connected MLT-2 resistors with a resistance of 3 kOhm.

Diodes VD1 and VD2 must be designed for a current of at least 300 mA and a reverse voltage of at least 400 V (VD1) and 100 B (VD2). Capacitor C1 of the MBM type for a voltage of at least 400 V. Its capacitance (a fraction of a unit of microfarad) is selected experimentally. Thyristor VS1 type KU201K, KU201L, KU202K KU202N. Transformators B2B ignition coil (6 V) from a motorcycle or car.

The device can use a horizontal scanning television transformer TVS-110L6, TVS-1 YULA, TVS-110AM.

A fairly typical circuit of a high-voltage pulse generator with a capacitive energy storage device is shown in Fig. 11.14.

Rice. 11.14. Scheme of a thyristor generator of high-voltage pulses with a capacitive energy storage device.

The generator contains a quenching capacitor C1, a diode rectifier bridge VD1 VD4, a thyristor switch VS1 and a control circuit. When the device is turned on, capacitors C2 and S3 are charged, thyristor VS1 is still closed and does not conduct current. The maximum voltage on capacitor C2 is limited by a zener diode VD5 of 9V. In the process of charging capacitor C2 through resistor R2, the voltage at potentiometer R3 and, accordingly, at the control transition of thyristor VS1 increases to a certain value, after which the thyristor switches to a conducting state, and capacitor SZ through thyristor VS1 is discharged through the primary (low-voltage) winding of transformer T1, generating a high voltage pulse. After this, the thyristor closes and the process begins again. Potentiometer R3 sets the response threshold of thyristor VS1.

The pulse repetition rate is 100 Hz. An automobile ignition coil can be used as a high-voltage transformer. In this case, the output voltage of the device will reach 30...35 kV. The thyristor generator of high-voltage pulses (Fig. 11.15) is controlled by voltage pulses taken from a relaxation generator made on dinistor VD1. The operating frequency of the control pulse generator (15...25 Hz) is determined by the value of resistance R2 and the capacitance of capacitor C1.

Rice. 11.15. Electrical circuit of a thyristor high-voltage pulse generator with pulse control.

The relaxation generator is connected to the thyristor switch through a pulse transformer T1 type MIT-4. A high-frequency transformer from the Iskra-2 darsonvalization apparatus is used as the output transformer T2. The voltage at the device output can reach 20...25 kV.

In Fig. Figure 11.16 shows an option for supplying control pulses to thyristor VS1.

The voltage converter (Fig. 11.17), developed in Bulgaria, contains two stages. In the first of them, the load of the key element, made on the transistor VT1, is the winding of the transformer T1. Rectangular control pulses periodically turn on/off the switch on transistor VT1, thereby connecting/disconnecting the primary winding of the transformer.

Rice. 11.16. Option for controlling a thyristor switch.

Rice. 11.17. Electrical circuit of a two-stage high-voltage pulse generator.

An increased voltage is induced in the secondary winding, proportional to the transformation ratio. This voltage is rectified by diode VD1 and charges capacitor C2, which is connected to the primary (low-voltage) winding of high-voltage transformer T2 and thyristor VS1. The operation of the thyristor is controlled by voltage pulses taken from the additional winding of transformer T1 through a chain of elements that correct the shape of the pulse.

As a result, the thyristor periodically turns on/off. Capacitor C2 is discharged onto the primary winding of the high-voltage transformer.

High-voltage pulse generator, fig. 11.18, contains a generator based on a unijunction transistor as a control element.

Rice. 11.18. Circuit of a high-voltage pulse generator with a control element based on a unijunction transistor.

The mains voltage is rectified by the diode bridge VD1 VD4. The ripples of the rectified voltage are smoothed out by capacitor C1; the charging current of the capacitor at the moment the device is connected to the network is limited by resistor R1. Through resistor R4, capacitor S3 is charged. At the same time, a pulse generator based on a unijunction transistor VT1 comes into operation. Its “trigger” capacitor C2 is charged through resistors R3 and R6 from a parametric stabilizer (ballast resistor R2 and zener diodes VD5, VD6). As soon as the voltage on capacitor C2 reaches a certain value, transistor VT1 switches, and an opening pulse is sent to the control transition of thyristor VS1.

Capacitor SZ is discharged through thyristor VS1 to the primary winding of transformer T1. A high voltage pulse is formed on its secondary winding. The repetition rate of these pulses is determined by the frequency of the generator, which, in turn, depends on the parameters of the chain R3, R6 and C2. Using the tuning resistor R6, you can change the output voltage of the generator by about 1.5 times. In this case, the pulse frequency is regulated within the range of 250... 1000 Hz. In addition, the output voltage changes when selecting resistor R4 (ranging from 5 to 30 kOhm).

It is advisable to use paper capacitors (C1 and SZ for a rated voltage of at least 400 V); The diode bridge must be designed for the same voltage. Instead of what is indicated in the diagram, you can use the T10-50 thyristor or, in extreme cases, KU202N. Zener diodes VD5, VD6 should provide a total stabilization voltage of about 18 V.

The transformer is made on the basis of TVS-110P2 from black and white televisions. All primary windings are removed and 70 turns of PEL or PEV wire with a diameter of 0.5...0.8 mm are wound onto the vacant space.

Electrical circuit of a high voltage pulse generator, Fig. 11.19, consists of a diode-capacitor voltage multiplier (diodes VD1, VD2, capacitors C1 C4). Its output produces a constant voltage of approximately 600 V.

Rice. 11.19. Circuit of a high-voltage pulse generator with a mains voltage doubler and a trigger pulse generator based on a unijunction transistor.

A unijunction transistor VT1 type KT117A is used as a threshold element of the device. The voltage at one of its bases is stabilized by a parametric stabilizer based on a VD3 zener diode of type KS515A (stabilization voltage 15 B). Through resistor R4, capacitor C5 is charged, and when the voltage at the control electrode of transistor VT1 exceeds the voltage at its base, VT1 switches to a conducting state, and capacitor C5 is discharged to the control electrode of thyristor VS1.

When the thyristor is turned on, the chain of capacitors C1 C4, charged to a voltage of about 600...620 V, is discharged into the low-voltage winding of the step-up transformer T1. After this, the thyristor turns off, the charge-discharge processes are repeated with a frequency determined by the constant R4C5. Resistor R2 limits the short circuit current when the thyristor is turned on and at the same time is an element of the charging circuit of capacitors C1 C4.

The converter circuit (Fig. 11.20) and its simplified version (Fig. 11.21) is divided into the following components: network suppression filter (interference filter); electronic regulator; high voltage transformer.

Rice. 11.20. Electrical circuit of a high voltage generator with a surge protector.

Rice. 11.21. Electrical circuit of a high voltage generator with a surge protector.

Scheme in Fig. 11.20 works as follows. The capacitor SZ is charged through the diode rectifier VD1 and resistor R2 to the amplitude value of the network voltage (310 V). This voltage passes through the primary winding of transformer T1 to the anode of thyristor VS1. Along the other branch (R1, VD2 and C2), capacitor C2 is slowly charged. When, during its charging, the breakdown voltage of dinistor VD4 is reached (within 25...35 V), capacitor C2 is discharged through the control electrode of thyristor VS1 and opens it.

Capacitor SZ is almost instantly discharged through the open thyristor VS1 and the primary winding of transformer T1. The pulsed changing current induces a high voltage in the secondary winding T1, the value of which can exceed 10 kV. After the discharge of the capacitor SZ, the thyristor VS1 closes and the process repeats.

A television transformer is used as a high-voltage transformer, from which the primary winding is removed. For the new primary winding, a winding wire with a diameter of 0.8 mm is used. Number of turns 25.

For the manufacture of barrier filter inductors L1, L2, high-frequency ferrite cores are best suited, for example, 600NN with a diameter of 8 mm and a length of 20 mm, each having approximately 20 turns of winding wire with a diameter of 0.6...0.8 mm.

Rice. 11.22. Electrical circuit of a two-stage high-voltage generator with a field-effect transistor control element.

A two-stage high-voltage generator (author Andres Estaban de la Plaza) contains a transformer pulse generator, a rectifier, a timing RC circuit, a key element on a thyristor (triac), a high-voltage resonant transformer and a thyristor operation control circuit (Fig. 11.22).

Analogue of transistor TIP41 KT819A.

A low-voltage transformer voltage converter with cross-feedback, assembled on transistors VT1 and VT2, produces pulses with a repetition frequency of 850 Hz. To facilitate operation when large currents flow, transistors VT1 and VT2 are installed on radiators made of copper or aluminum.

The output voltage removed from the secondary winding of transformer T1 of the low-voltage converter is rectified by the diode bridge VD1 VD4 and charges capacitors S3 and C4 through resistor R5.

The thyristor switching threshold is controlled by a voltage regulator, which includes a field-effect transistor VTZ.

Further, the operation of the converter does not differ significantly from the previously described processes: periodic charging/discharging of capacitors occurs on the low-voltage winding of the transformer, and damped electrical oscillations are generated. The output voltage of the converter, when used at the output as a step-up transformer of an ignition coil from a car, reaches 40...60 kV at a resonant frequency of approximately 5 kHz.

Transformer T1 (output horizontal scan transformer) contains 2x50 turns of wire with a diameter of 1.0 mm, wound bifilarly. The secondary winding contains 1000 turns with a diameter of 0.20...0.32 mm.

Note that modern bipolar and field-effect transistors can be used as controlled key elements.

Nowadays, you can often find outdated CRT TVs in the trash; with the development of technology, they are no longer relevant, so now they are mostly getting rid of them. Perhaps everyone has seen on the back wall of such a TV an inscription in the spirit of “High voltage. Do not open". And it hangs there for a reason, because every TV with a picture tube has a very interesting little thing called TDKS. The abbreviation stands for “diode-cascade line transformer”; on a TV it serves, first of all, to generate high voltage to power the picture tube. At the output of such a transformer, you can get a constant voltage of as much as 15-20 kV. The alternating voltage from the high-voltage coil in such a transformer is increased and rectified using a built-in diode-capacitor multiplier.
TDKS transformers look like this:

The thick red wire extending from the top of the transformer, as you might guess, is designed to remove high voltage from it. In order to start such a transformer, you need to wind your primary winding around it and assemble a simple circuit called a ZVS driver.

Scheme

The diagram is presented below:

The same diagram in another graphical representation:

A few words about the scheme. Its key link is IRF250 field-effect transistors; IRF260 are also well suited here. Instead of them, you can install other similar field-effect transistors, but these are the ones that have proven themselves best in this circuit. Between the gate of each transistor and the minus of the circuit, zener diodes are installed for a voltage of 12-18 volts; I installed zener diodes BZV85-C15, for 15 volts. Also, ultra-fast diodes, for example, UF4007 or HER108, are connected to each of the gates. A 0.68 µF capacitor is connected between the drains of the transistors for a voltage of at least 250 volts. Its capacitance is not so critical; you can safely install capacitors in the range of 0.5-1 µF. Quite significant currents flow through this capacitor, so it can heat up. It is advisable to place several capacitors in parallel, or take a capacitor for a higher voltage, 400-600 volts. There is a choke in the diagram, the rating of which is also not very critical and can be in the range of 47 - 200 µH. You can wind 30-40 turns of wire on a ferrite ring, it will work in any case.

Manufacturing

If the inductor gets very hot, then you should reduce the number of turns, or take a wire with a thicker cross-section. The main advantage of the circuit is its high efficiency, because the transistors in it hardly heat up, but, nevertheless, they should be installed on a small radiator for reliability. When installing both transistors on a common radiator, it is imperative to use a heat-conducting insulating gasket, because the metal back of the transistor is connected to its drain. The supply voltage of the circuit lies in the range of 12 - 36 volts; at a voltage of 12 volts at idle, the circuit consumes approximately 300 mA; when the arc is burning, the current rises to 3-4 amperes. The higher the supply voltage, the higher the voltage will be at the output of the transformer.
If you look closely at the transformer, you can see the gap between its body and the ferrite core is approximately 2-5 mm. The core itself needs to be wound with 10-12 turns of wire, preferably copper. The wire can be wound in any direction. The larger the wire, the better, but a wire that is too large may not fit into the gap. You can also use enameled copper wire; it will fit into even the narrowest gap. Then you need to make a tap from the middle of this winding, exposing the wires in the right place, as shown in the photo:

You can wind two windings of 5-6 turns in one direction and connect them, in this case you also get a tap from the middle.
When the circuit is turned on, an electric arc will occur between the high voltage terminal of the transformer (thick red wire at the top) and its negative terminal. The minus is one of the legs. You can determine the required minus leg quite simply by placing the “+” next to each leg in turn. The air breaks through at a distance of 1 - 2.5 cm, so a plasma arc will immediately appear between the desired leg and the plus.
You can use such a high-voltage transformer to create another interesting device - Jacob's ladder. It is enough to arrange two straight electrodes in a “V” shape, connect a plus to one, and a minus to the other. The discharge will appear at the bottom, begin to creep up, break at the top and the cycle will repeat.
You can download the board here:

(downloads: 581)

Due to high power consumption, the horizontal scan output stage operates under severe temperature conditions, and therefore most TV failures are associated with it.

Usually the biggest problems arise when the split transformer fails. An example is a malfunction in the LOEWE CLASSIC TV on the C8001 STEREO/85 chassis.

During the troubleshooting process, it was found that the horizontal output transistor T539 type BU508A (split transformer 2761419) was broken.

Unfortunately, it was not possible to find the original transformer, so we had to solve the problem in another way.

A fragment of the horizontal scan output stage circuit of this TV is shown in Fig. 1. The voltage of the secondary windings of the split transformer, as well as their polarity, is indicated by most European companies on the printed circuit board, directly at the output. If this information is missing, you can proceed as follows. As a rule, the overwhelming majority of transformer failures are recorded in their high-voltage part, while the secondary windings are in working condition. Therefore, having found among them the filament winding of the kinescope (6.3 V), you can apply filament voltage to it from a working TV (for example, from pin 7-8 TVS110-PTs15 of the 3USTST TV), having previously disconnected it from the contacts of the kinescope panel. The polarity of the pulses of the secondary windings is determined based on the polarity of the rectifier diode connected to this winding.

In our case, winding 9-10 of the transformer is the power winding of the video amplifiers. But this method of determining the polarity and voltage of the secondary windings has to be resorted to extremely rarely, since in the reference literature there are almost all split transformer circuits indicating the voltages of the primary and secondary windings, as well as their polarity.

In our particular case, it was found that the voltages of the secondary windings of the transformer are intended to power the following functional units:

9-1 - 60 V - to generate the tuner tuning voltage;

9-10 - 200 V - for powering video amplifiers;

9-5 - 6.3 - for powering the kinescope filament;

9-8 - 12 V - for powering the radio channel and color channel microcircuits;

9-6 - 27 V - for power supply of vertical scanning.

It should be noted that voltages of 12 and 27 V are obtained by rectifying not the negative part of the horizontal pulse, but its positive component, which should be paid special attention to in the absence of documentation for the transformer. A guide here can be the power winding of video amplifiers (9-10), the voltage of which (usually 180220 V) is obtained by rectifying horizontal pulses of positive polarity.

Having dealt with the secondary windings, we will begin to manufacture a unit designed to replace a faulty split transformer. The design is based on the horizontal scan output stage of the 3USTST TV, the diagram of which is shown in Fig. 2. The winding data of the transformer windings are given in the table.

Winding	Power, W	Wire type	Number of turns

The purpose of the secondary windings of the transformer is as follows:

7-8 - kinescope filament power winding;

4-5, 4-3, 4-6, 4-2 - power windings of the raster correction submodule and convergence unit;

14-15 - high-voltage winding.

Based on the above, it is obvious that secondary windings 4-5, 4-6 of TVS 110-PTs16 can be used instead of windings 9-1, 9-10 of a split transformer, winding 4-2 - instead of winding 9-6, winding 7-8 - instead of winding 9-5. As for obtaining a negative polarity voltage of 150 V, here you will have to wind up winding 4-3 to a power of 10 W. When using a TVS 110-PTs15 transformer, you will additionally have to wind the missing windings 3-2, 5-6. It is convenient to wind additional windings on the free side of the FA core using MGTF-0.3-0.5 or PEV-2-0.4 wire. In the latter case, insulating gaskets are required between the core and the winding.

When winding, you need to pay attention to the in-phase alignment of the additional windings. The high-voltage unit in the basic circuit designs repeats a similar unit of the 3USCT TV. The difference lies only in the methods of supplying the kinescope with accelerating voltage and a signal for devices for stabilizing the image size along the lines and limiting the current of the rays.

Resistors for adjusting the focusing and accelerating voltages are used from a failed split transformer and glued with heat-resistant glue to the housing of the UN9/27-1.3 A multiplier.

If these resistors cannot be removed without damaging them from the body of the split transformer, then the circuit for supplying these voltages to the kinescope should be implemented similarly to that used in 3USTST TVs.

The redesigned circuit of the horizontal scanning output stage of the mentioned LOEWE TV is shown in Fig. 3.

TVS 110-PTs16 is installed in place of the soldered split transformer at a distance of 1 cm from the surface of the printed circuit board, and its terminals are soldered according to the diagram shown. If there are no errors in installation, the output stage, as a rule, starts working immediately, and a raster appears on the screen. By applying a color stripe signal to the TV input, the focusing and accelerating voltages are adjusted, then the horizontal and vertical dimensions of the raster are assessed.

Due to the fact that the parameters of winding 9-12 of TVS 110-PTs16 are not completely identical to the parameters of winding 2-4 of a split transformer, an increased or decreased horizontal raster size may occur. If it is impossible to set a raster of normal size using the variable resistor R586 (horizontal size), then you will need to select the capacitance of the capacitor C540, having previously installed R586 in the middle position. Adjusting the vertical size usually fits into the value of the variable resistor R564.

Then it is necessary to check the secondary voltages of the windings of the TVS 110-PTs16 transformer. In this TV, the voltage value after the rectifiers on the filter capacitors is indicated on the printed circuit board, so measurements are made with a DC voltmeter. If there is only the amplitude of the pulses on the secondary windings, it is measured with an oscilloscope. As practice has shown, the amplitude of the pulses of the secondary windings can differ from the nominal value within ±10%, which does not negatively affect the operation of the TV. If the amplitude differs by more than 10%, it is necessary to carefully examine the shape of the horizontal pulse for the absence of emissions and excitation at high frequencies. To do this, the oscilloscope is connected to any secondary winding of TVS 110-PTs16, and adjustment is made by selecting the capacitances of capacitors C547, C546, C583, C540. If the pulse amplitude of the secondary windings exceeds the nominal value by more than 10%, it is necessary to reduce the number of turns L additional. until it meets the nominal value, and as for windings 4-5, 4-6, 4-2, there is a ballast resistor in the circuit of these windings (for example, R506 in the +200 V circuit). By increasing the value of this resistor, the rectified voltage is brought closer to the nominal value.

The next stage is adjusting the kinescope filament voltage. Due to the high identity of the parameters of split transformers and picture tube filaments, this TV does not have a filament voltage regulation system, and an unregulated inductor L541 is connected in series with the filament winding. The voltage value is monitored by an oscilloscope directly at the contacts of the kinescope panel. To carry out the adjustment, a resistor Rd type C5-37 is installed in series with the inductor L541, by selecting the resistance of which (within 13 Ohms) the rated voltage is set. Good results are obtained by installing an adjustable throttle L5 instead of L541 (for example, from the KR-401 module from the Horizon plant). If the filament voltage is less than the nominal value, an additional 1-2 turns are wound in series with winding 7-8 TVS110-PTs16 and the adjustment is made again. The UN9/27-1.3 A multiplier is installed in any convenient place on the TV body and connected to the pin. 15 fuel assemblies with high-voltage wire.

As practice has shown, the power of the TVS 110-PTs16 transformer is quite sufficient to operate the output stages of televisions with a screen size of 6770 cm diagonally. The proposed repair method is quite labor-intensive, but nevertheless, sometimes it is the only way to “revive” a TV if it is not possible to purchase an original one split transformer. Several televisions from the mid-80s were repaired in a similar way, after which they showed high reliability and stability in operation.