JPS58501492A - Efficient current modulator for inductive loads - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention Background of the invention of an efficient current modulator that is effective for inductive loads The present invention relates to a current modulator, in particular to a current modulator that allows current to flow from a DC power supply through a load to the ground side of a circuit. Related to current modulators with improved practicality and efficiency used to fully modulate the current It is.

Traditionally, this type of current modulator uses a switching device between the load and the circuit ground. This switching device is responsible for the modulation signal supplied to the switching device. The total current passing through the load is modulated depending on the signal. And the load and switching device For full protection and protection of loads and switching equipment from very high currents, An oversheet clipping diode is installed between the switching device and the power supply side of the load. The board is connected.

However, this conventional current modulator generates an alternating current across the inductive load. can't work like that. This means that the terminal voltage on the supply side of the load is The diode mentioned above becomes forward biased and becomes negative. This is to short-circuit the entire load.

Summary of the invention The present invention provides an efficient current modulator for use with inductive loads.

The present invention is a current transformer that adjusts the current flowing from the DC power source to the ground point of the circuit through all the loads. It is a regulator, and it modulates the entire current passing through the load according to the supplied modulation signal. A switching device connected between the ground point of the circuit and a switching device described in “-” a first induction coil connected between the current and the load; In order to absorb all the energy induced in the first induction coil, a second induction coil which is interconnected, and the energy received is Connected between the power supply side terminal of the load and the second induction coil for transfer to the source side. It is equipped with diodes and all. The second induction coil is connected to the first induction coil. A conductive diode is forward biased to transfer energy to the power supply side of the load. However, it is not possible to short-circuit both ends of the inductive load.

Since the energy is transferred to the power supply side of the load by the above-mentioned diode, the present invention is not applicable. Current modulators are efficient.

In addition, if a 7F, IH (wave switching device) is used, the entire efficiency of the current modulator can be improved. It can be improved. And high frequency switching devices have short conduction times. Therefore, the power lost in high frequency switching devices is small.

Furthermore, if an air core f is used as a mutually coupled induction coil, the electric The efficiency of the flow modulator can be improved.

This can be achieved by using both an air-core induction coil and high-frequency switching. This is because the heat loss inside can be completely reduced.

Other features of the invention will also be discussed in the description of the preferred embodiments.

Brief description of the drawing FIG. 1 is a circuit diagram showing all blocks and circuits of one embodiment of the current modulator of the present invention. Ru.

FIG. 2 is a circuit diagram of a modulation signal generator used in the current modulator of FIG. 1.

3A to 3E are waveform diagrams of signals generated in the modulation signal generator of FIG. 2. It is.

FIG. 4 is a circuit diagram showing different embodiments of the current modulator of the present invention in blocks and circuits. It is.

FIG. 5 is a circuit diagram of a modulation signal generator used in the current modulator of FIG. 4.

6A to 6F are waveform diagrams of signals generated in the modulation signal generator of FIG. It is.

Description of the preferred embodiment FIG. 1 shows an embodiment of the current modulator of the present invention, which has a high frequency Wave number switching element Q1, first induction coil L1, second induction coil L2.2 Two diodes D1 and D2. Three capacitors CI, C2 and C3 and modulation It consists of a signal generator 10. Switching element Q1 switches at high frequency. This is a VMO 8FET power transistor that can perform all switching operations. transistor Q 1 is connected between one end of the load 12 and the ground point of the circuit, and is connected to the modulation signal generator 10. In response to the modulation signal supplied to the gate of transistor Q1 through line 14, to change the current passing through the entire load 12. The terminal Vs of the DC power supply is a protection diode. It is coupled to the other end of the load 12 through D1. The load 12 is a capacitor CI and It is separated from the circuit ground by C2.

A first induction coil L1 is connected between transistor Q1 and load 12.

The second induction coil L2 is mutually coupled with the first induction coil L1 so that the entire load 12 is The entire bone takes the energy induced in the first induction coil L1 by the change in the current passing through it. . The first and second induction coils Ll and L2 are arranged in one air-core (air-fil Tightly mounted on the led core by bifilar or concentric winding. It is fully wrapped.

The first and second induction coils L1 and L2 are conductively separated from each other. Immediately In other words, there is no direct current path between the coils L1 and L2. However, coil L1 and L21″1, coil L] and the problem caused by the weak mutual coupling between L2 To minimize this, it is coupled by capacitor C3.

The diode D2 is connected between the second induction coil L2 and the power supply side of the load 12. , all of the energy received from the second induction coil L2 is transferred to the power supply side of the load 12. .

The modulation signal generator 10 supplies a high frequency signal to the gate of the switching transistor Q1. It is provided to supply all the regulated signals. selected in this example The high frequency used is 100 kHz.

A preferred embodiment of modulation signal generator 10 is shown in FIG. Modulation signal generation The circuit 10 consists of a Seamit inverter II, a resistor R1 and a capacitor C4. It has a free running oscillator i. 3A, the oscillator generates a high frequency nocellus-like signal on line 16, as shown in FIG. 3A. All square wave signals are generated. Resistor R1 is connected between the input and output of inverter 11. Also, capacitor C4 is connected between inverter ■1 and the ground point of the circuit. It is.

Further, the modulation signal generator 10 further includes a differential circuit consisting of a capacitor C5 and a resistor R2. (npn) lannostar Q2, current limiting resistor R3, capacitor C6 and high The entire row includes a comparator consisting of a gain amplifier A1.

The square wave signal on line 16 is passed through a differentiator circuit consisting of resistor R2 and capacitor C5. is differentiated, and the part where the square wave on line 16 rises (a pos ive g (oingtransition), the transistor Q2 is made fully conductive. capacitor C6 discharges every time transistor Q2 conducts, but transistor Q2 cuts off. During this time, the current flowing from the voltage terminal Vc of the DC power supply through the resistor R3 causes It will be charged. Therefore, as shown by the solid line in FIGS. 3B and 3D, the comparator A A triangular wave is generated on a line 18 connected to one input terminal of the .

The other input terminal of comparator AI has a low frequency signal which is compared with the triangular wave on line ]8. A reference signal VR is input. The frequency of the reference signal varies as the current through load 12 changes. is selected depending on the predetermined low frequency to be applied.

Typically, this predetermined low frequency is 50 or 60 Hz.

The amplitude of the reference signal vR varies at a predetermined low frequency.

When the reference signal 2 VR has a relatively large amplitude (see Figure 3B), a relatively short data A pulse-like modulated signal of a good frequency with a utility cycle (see Figure 3C). ) is a line from the output of comparator A to switching transistor Q+ (Figure 1). All 14 sections are given. and the reference signal has a relatively small amplitude (see Figure 3D). ), when the duty cycle is relatively long (the current flowing through the third E load 12 The amplitude of is proportional to the amount of time that switching transistor Q1 is conducting. do. And the time during which transistor Q1 is conductive is a high-frequency, somewhat loop-like change. It is proportional to the data cycle of the modulation signal. Therefore, the current through the entire load 12 changes at a predetermined low frequency of the reference signal vR.

The inductance of the first induction coil L1 (the direct and the spiral modulation on line 14) negligible current when the signal has a minimum discontinuous duty cycle of 4 Full rise and the pulsed modulated bird signal on line 14 has the maximum discontinuous duty. Sufficient inductor to allow a relatively large current to rise during cycle 4 is set to . Switching/l/lansostar Q1 is shut off. When there is no current passing through the first induction coil between each coil, the two mutual connections The energy stored in the combined induction coils L1 and L2 is transferred to the first induction coil L1. Make the point 20 on the switching transistor side of the switch all positive and high voltage. This means that This is generally known as overshoot. In the current modulator of the present invention, Induction energy from the first induction coil L1 to the second induction coil L2? combine and Energy received in the second induction coil L2? 9 items 1 via Daito D2 Since it returns to the power supply side of 2, overshoot can be minimized as much as possible. . If you do not minimize the open neat total, the switching transistor This will cause damage to Q1 and the first induction coil Ll. Diode D2Th The energy returned to the power supply side of the load 12 through the average current through diode D2 The total current supplied from the power supply terminal ■s through the diode D1 by an amount equal to let

In the current modulator of FIG.

Even if the instantaneous voltage at point 22 on the switching transistor side exceeds the power supply voltage Vs”c, the die Ord D2 does not short circuit load 12. This is the induction coil L1 and L2 are not electrically conductively coupled to each other, and a negative This is because there is no direct current path that returns to the power source side of the load. Therefore, the instantaneous voltage at point 22 vibrates at twice the power supply voltage ■s.

If the switching transistor Q1 is conducting for a short period of time, the passing through the induction coil L during the fast stepchange Since the current is small, the losses (minimum) dissipated in transistor Q1 during the conduction period are become. If the saturation voltage of transistor Q1 is lowered, the amount of energy consumed by transistor Q1 will be reduced. The average power output is at a minimum during the “on” time, and when transistor Q1 is If it is shut off with a short shut-off time, the All losses can be kept very small. Therefore, switching at high frequencies Ching is preferred.

The resistance values of induction coil L] and L2 are very small, so these induction coils The heat loss in L1 and L2 is very small. In the current modulator of Figure 1, typically 96% of the input power is supplied to the load and 4% is applied to the inductive diode D2. consumed.

Embodiment 4 of a current modulator according to the invention particularly suitable for using a transformer as a load This will be explained with reference to all figures 4, 5 and 6. The load is the primary winding S of transformer T1, The primary winding S is connected between the output terminal Vo and the ground point of the circuit.

And the current modulator includes first and second high frequency switching elements Q1.1 and It has Q12t'. Similar to the embodiment of FIG. 1, the switching elements Qll and Q12 is a VMO that can switch at high frequencies such as 100kHz. It consists of 3FET/e-war transistor.

The current modulator of FIG. Second. Third and fourth induction coil L 11 , T, , 12, L1.3 and Ll-4, and the first and second diode D1] and D12, capacitors C1l and C12, and modulation signal generator 24 and a first switching transistor Qll connects one end 28 of the primary winding P to the circuit. This transistor Qll is provided between the modulation signal generator 24 and the is supplied from line 30 to the gate of switching transistor Qll. The primary winding P? Change the total current flowing through it. And the first invitation A conducting coil l711 is connected between the first transistor Qll and one end 28 of the primary winding P. It is connected.

A second induction coil T, 12 is mutually coupled to the first induction coil and The conductive coil L12 absorbs all the energy induced in the first induction coil by the change in current. Remove the bones. The first and second induction coils Lll and L2 are double-wound or Tightly wrapped with concentric windings. The first and second induction coils are electrically conductive to each other. are separated.

The first diode D1.1 connects the second induction coil I, 12 and the other end 32 of the primary winding P. The diode Dll is connected through the other end 32 of the primary winding P. All the energy received from the second induction coil L1.2 is transferred to the power supply terminal Vs. .

The second switching transistor Q1.2 is in circuit contact with the other end 32 of the primary winding P. The switching transistor Q12 outputs the modulation signal. A line is connected from the generator 21 to the gate of the second switching/l/lannostar Q12. 34. The total current through the primary winding pt changes in response to the second modulation signal supplied throughout. let The third induction coil L13 connects the transistor Q12 to the other end of the primary winding P. is connected between.

A fourth induction coil L14 is interconnected to the third induction coil L13, and a fourth The induction coil L14 generates energy induced into the third induction coil by a change in current. Remove the whole bone. The third and first induction coils L13 and Li2 are connected to the air core. Tightly wrapped with heavy or concentric windings. and the third and fourth leads The coils are conductively separated from each other.

A second diode D12 connects the fourth induction coil L12 and one end 28 of the primary winding P. This diode D12 passes through the entirety of one end 28 of the primary winding P. 4 induction coil L], transfers the energy received from 4 to the power terminal ■s .

The modulation signal generator 24 has first and second switches.

The first and second variables are applied to the gates of balance transistors Qll and G12, respectively. It is provided to supply all the modulation signals. The first and second modulated signals are The primary winding P is supplied such that only one end is connected to the circuit ground at any time. Ru.

As shown in FIG. 5, one preferred embodiment of the modulation signal generator 24 includes a first hysteresis lysis inverter G1 and a resistor connected between the input and output of inverter G1. Capacitor C1l connected between resistor R11 and the input of inverter G1 and ground point It has an oscillation circuit 4 consisting of.

Further, the modulation signal generator 24 has an input terminal connected to an output terminal of the inverter G1. second hysteresis inverter G2, input amplifier A2 and resistor R], 2. R1 3° R14 and R15 and 4 layer reference signal terminal V.

is connected to the inverting input terminal of amplifier A2 via resistor R12. Inverted again The input terminal is connected to the power supply terminal Vc via a resistor R13'f. Amplifier A2 The non-inverting input terminal of is connected to the ground point of the circuit. Resistor R14 connects amplifier A2 is connected between the inverting input and output of. The output of amplifier A2 is It is connected to the input of the lysis inverter G1 via a resistor 15.

The oscillator consisting of inverter G1, resistor R11 and capacitor C1l is shown in FIG. 6A. As shown in FIG. 3, a square wave ie loop signal is generated on line 30. Inverter G 2, all the signals on line 30 are inverted and the supplementary square wave/gurus-like signal is all on line 34. Occur. The signals on lines 30 and 3.1 each have the same duty cycle 4, so to speak, the average current passing through the primary winding P' of the transformer T1 of the current modulator of FIG. force becomes zero.

When the output of line 30'2 is high, the condenser The sensor C1l is charged through the resistor R1lt- and has a waveform 4 as shown in Figure 6B. A signal is generated on the input terminal 36 of the total inverter G1. At the input terminal 36 The voltage of No. A is up to the upper switching thread of inverter G1, 7 hold■2 When the output of inverter G1 increases, the output of inverter G1 drops to low as shown in Figure 6A. Chiru. The capacitor C1l is configured such that the voltage of the signal at the input terminal 36 is connected to the inverter G1. Lower switching thread of , through resistor R1lt until it drops to 7 hold V1. At that point, inverter G1 switches high again.

The respective outputs of inverters G1 and G2 are output on lines 30 and 34. The data cycle of the signal is determined by the charging or discharging of the capacitor C1l. rate or rate? Can be changed by changing.

This is the current 7 changes flowing through the resistor R15t to the input terminal 36 of the inverter G. This is done by This change in current is applied to the reference signal terminal V I'l. occurs in response to a reference signal having a predetermined low frequency 4. The frequency of the reference signal is Depending on the predetermined low frequency at which the current through the primary winding P of the generator T1 is to be varied Selected. Typically, this predetermined low frequency is 50 or 60 Hz.

Amplifier A2 completely inverts the reference signal supplied to terminal VR and inverts it via resistor R15. A current 4 to be applied to the transfer input terminal 36 is generated. This current is the capacitor C When charging or discharging 1l, supplement the current through resistor R1lt or resist this current. Ru.

The output terminal of amplifier A2; the voltage at 38 is equal to the voltage at the inverting input terminal 36. When it is negative with respect to the average value, as shown in Figure 6C, capacitor C], 1 is slowly It charges quickly and discharges quickly. This results in a long duty cycle for the Figure 6D signal. ・This is because a cycle is given. On the contrary, the pulse shape of the second inverter G2 The output signal also has a short duty cycle of 4.

The voltage at the output terminal 38 of amplifier A2 is equal to the voltage at the inverter input terminal 36. is positive with respect to the average value, capacitor C1l charges quickly as shown in Figure 6E. It is charged and then slowly discharged. This is the inverter output signal on line 30 This is because a large duty cycle is given as shown in FIG. 6F.

On the contrary, the signal-like output signal of the second inverter G2 simultaneously has a long data signal. It has 4 cycles.

A dual circuit is connected to each gate of switching transistors Q1.1 and Q12. 1 of the transformer T by applying all pulse modulation signals with different T cycles. The average current passing through the next winding Pk does not become zero. Primary winding pt flow The amount of current flowing through each of the switching transistors Q], l and Q12 is 1'i applied to the cell through lines 30 and 34; It is proportional to the difference in the jnity cycles of "l"i-.

Duty cycle of malus-like modulation signal north of line 30 I on line 34 When the duty cycle of the pulse modulation signal becomes larger than that of the main winding pt flows The current is greater in the direction from the center tap 26 toward one end 28.

Changes in the amplitude and direction of the current flowing through the main winding Pk are determined by the amplifier of the modulation signal generator 24. It is responsive to changes in the instantaneous voltage appearing at output terminal 38. And the reference signal terminal v When a predetermined low frequency reference signal 4 is applied to R, the output terminal Vo of the secondary winding of transformer T1 A predetermined low frequency output signal is generated. Therefore, the current modulator in FIG. , it is particularly suitable for obtaining a low frequency sinusoidal output signal 4 with low distortion.

Basically, the switching transistor Q11 of the current modulator shown in Fig. Conductive coils L1.1 and L12 as well as diode D1.1 and switching transistor Q12, induction coils L13 and L1.4, and diode D], The operation and characteristics of each combinational circuit configuration in 2 are as follows: Switching transistor A1, induction coils Q1 and Q2 and diode DI The operation and characteristics of the combinational circuit configuration are the same.

A different feature of the current modulator in Figure 4 is that the primary winding P is It uses an energy recovery path. This is as follows. If two Assuming that the cathodes of diodes D1.1 and Dl2 are connected to the power supply terminal VsK. , the energy received from the induction coils L12 and Li2 is returned to the power supply. Become. However, these two diodes Dll and Dl2 are shown in FIG. When cross-connected across ends 28 and 32 of the primary winding P, the recovered energy is Not only does it flow back to the source, but the current flows through all the non-conducting terminals on the opposite side of the primary winding. It returns to the source and becomes a transformer. The energy recovered from the induction coil is The inductive kick voltage (1st The current passing through the high voltage D12 called “uctive kick” is energy. tends to remain relatively constant at different voltages during recovery.

2/3 Figure 5

Claims (1)

[Claims] 1 Current modulation that modulates the entire current flowing from the DC power source to the circuit ground point through the load In order to change the total current passing through the load according to the modulation signal applied to the device, a switching device connected between the load and a ground point of the circuit; a first induction coil connected between the pulling device and the load; and a first induction coil connected between the pulling device and the load; a first induction coil interconnected to the coil for receiving energy induced in the first induction coil; a second induction coil coupled between the second induction coil and the power supply side of the load; and a diode for transferring all of the energy to the power supply side of the load; an induction coil is electrically conductively separated from the first induction coil. current modulator. 2. The switching device is a high frequency switching element. A current modulator according to claim 1. 3. Means for supplying all the high-frequency pulse-like modulated signals to the switching device. 3. A current modulator as claimed in claim 2, characterized in that it has all features. ・1 A claim characterized in that the switching device is an MO8 semiconductor element Current modulator according to range 3. 5. The switching device is a VMO8FET power transistor. 6. A current modulator according to claim 5 with all the features. 6. The means for supplying all of the modulation signals to the switching device is configured to supply high frequency pulses to the switching device. A first means for generating a signal in the form of a signal, and data of the signal in the form of a signal at a predetermined low frequency. and second means for changing the predetermined low temperature cycle. The high-frequency pulse-like modulation signal is used to vary the current through the load with frequency. The electric current according to any one of claims 3 or 5, characterized in that the electric current is generated. modulator. 7. The second means adjusts the data according to the reference signal having the predetermined low frequency. Claim 6 is characterized in that it is provided to change the tea cycle. Current modulators as described in Section. 8. Claim 3, wherein the induction coil has an air core 2. Current modulators as described in Section. 9 Current flowing from the DC power supply connected to the load to the grounding point of the circuit through the entire load In a current modulator that performs full modulation, a current modulator connected between one end of the load and the ground point. a first switching element that changes the current through the load in response to a first modulation signal applied to the first switching element; a switching device connected between the first switching device and the one end of the load; a first induction coil; and a first induction coil interconnected with the first induction coil to be energized by a change in current. The energy induced in the first induction coil is transferred to the second induction coil and to the second induction coil. the second induction coil and the power supply; a first diode for transferring all of the energy to a source; and a first diode for transferring all of the energy to the source; A second modulation signal is connected between the ground point and the load, and the current flows through the entire load in response to a second modulation signal that is applied. The second switch that changes the flow. a switching device connected between the second switching device and the other end of the load; a third induction coil that is interconnected with the third induction coil to change the current; The total energy induced in the third induction coil is taken by the fourth induction coil and , between the fourth induction coil and the power source, from the fourth induction coil to the power source. A second diode that transfers all of the energy and only one end of the load is grounded at any time. means for applying a modulation signal to the two switching devices so as to the second induction coil is connected from the first induction coil and from the fourth induction coil; The coils are each electrically conductively separated from the third induction coil. current modulator. 10 The first diode is connected to the second induction coil and 1) the other end of the IJ negative load. The other end of the load is connected between the two ends of the load so that the electric current is supplied from the second induction coil to the other end of the load. transferring said energy to a source, said second diode being connected in front of said fourth induction coil; The fourth dielectric is connected between the one end of the load and the fourth dielectric is connected to the one end of the load. Claim 1 characterized in that all of the energy is transferred from the conducting coil to the power source. 9. The current modulator according to item 9. 11 The load has a center tap 2 and 9 the center tap has a full power supply. According to claim 10, the device further comprises means for connecting to a source current modulator. 12. The switching device is a high frequency switching device. 11. The current modulator according to claim 10. 13. Claim characterized in that the switching device is composed of an MO8 semiconductor element. 13. The current modulator according to item 12. 14 The switching device is a VMO8FET, a q-war transistor. 14. A current modulator according to claim 13, characterized in that: 15 The means for applying the modulation signal to the switching device is a high frequency Strip modulated signal? Claim 12, characterized in that: Current modulator as described. 16. The means for providing the modulation signal 2 to the switching device comprises first and second signals that complement each other. a first means for generating a second high frequency pulsed signal; and a first means for generating a second high frequency pulsed signal; at a predetermined low frequency so as to vary the current through the entire load at a predetermined low frequency. The first and second high frequency pulse-like signals have a duty cycle of 2; Claim 14 or 15, characterized in that it consists of the means 2. The current modulator described in . 17 The second means controls the duplex in response to the reference signal having the predetermined low frequency. Claim No. 17. The current modulator according to item 16. 18. Claim 1, characterized in that the induction coil has an air core 2. Current modulator according to item 5.