CN2898903Y

CN2898903Y - Special power supply for electronic-tube lining filament

Info

Publication number: CN2898903Y
Application number: CN 200620069561
Authority: CN
Inventors: 马廷和; 杨萍
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-02-21
Filing date: 2006-02-21
Publication date: 2007-05-09
Anticipated expiration: 2016-02-21

Abstract

A special power supply for electronic-tube lining filament is characterized in that: a switching power supply unit is employed in which a Pulse Width Modulation Circuit (PWM) is used as a control circuit; the switching power supply unit is a smoothing control circuit which can smoothly increase a basic voltage value from zero value to a rated value. The utility model can smoothly increase voltage for DIY electronic-tube lining filament on startup and stably supply power on operation in which the current impact on the DIY lining filament is prevented on startup, and the electronic-tube can still operate under a high-accuracy stable status. The utility model can averagely elongate the life-span of the electronic-tube by more than 5 times.

Description

Courage organic electronic spot silk dedicated power supply apparatus

Technical field:

The utility model relates to the filament power supply, a kind of filament dedicated power supply apparatus in the courage organic electronic pipe amplifier that is applied in of more specifically saying so.

Background technology:

The electron tube audio-frequency power amplifier, just usually said courage machine, the added voltage and current of its electron tube heater is the essential condition of electron tube operate as normal, it can make the cathode temperature of electron tube reach thousands of degree.Because the voltage that adds on the filament directly influences the life-span of electron tube, therefore to a certain degree stability and degree of accuracy to be arranged.But in the courage organic electronic tube power amplifier prior art, electron tube heater is an Alternating Current Power Supply.Because the voltage stabilizing measure of no degree of precision and have surge current impact etc. has not only influenced the serviceable life of electron tube greatly, and efficient low energy consumption height, the tonequality generation harmful effect that the ripple that the while Alternating Current Power Supply brings also can pair amplifier.

At present, the power supply of courage organic electronic spot silk, the general electric main that adopts is directly supplied with after the transformer step-down, its magnitude of voltage is subjected to the influence of voltage ripple of power network, degree of stability is lower, filament voltage then directly influences the filament temperature that is used for to the cathode for electron tube heating, and then influences the serviceable life of electron tube.

In addition, be in electron tube heater under the vacuum state when cold conditions, resistance is very little, and under the condition of high temperature when work, and it is big many that resistance is wanted.In the time of on the filament when operating voltage is added in cold conditions, can form surge current, because inner each the interelectrode distance of electron tube is very near, the impact that this surge current produces can cause the difference because of different electrode material thermal expansivity, and cause and bump utmost point fault, influence the serviceable life of electron tube.

Simultaneously, the Alternating Current Power Supply of filament can produce some backdrops, is the courage machine power amplifier of purpose to the pursuing high quality acoustics, can produce harmful effect, causes can't remedy scarce to shake.

In addition, owing to general switching power supply requires should reach load voltage value in the time at 20-50ms after its unlatching, thereby be not suitable for the filament power supply of courage organic electronic pipe.Moreover, the ordinary tap stabilized voltage supply all has the over-current over-voltage protection measure, also can protect the dash current that the cold conditions low-resistance of electron tube is produced because of " overcurrent ", thereby can't operate as normal.

Summary of the invention:

The utility model is for avoiding above-mentioned existing in prior technology weak point, a kind of courage organic electronic spot silk dedicated power supply apparatus being provided.This circuit arrangement can provide stable operating voltage and the level and smooth trigger voltage that rises for courage organic electronic spot silk, so that eliminate " surge current ", prolong tube life to greatest extent, guarantee the normal performance of electron tube operating characteristic, energy-conservation of consumption reduction is raised the efficiency.

The utility model technical solution problem adopts following technical scheme:

Design feature of the present utility model is that employing is the switching power supply of control circuit with pulse-width modulation circuit PWM, and be the described switching power supply setting level and smooth level and smooth control circuit that promotes its reference voltage to ratings of can starting from scratch, described level and smooth control circuit is by transistor Q and be arranged on the base stage of transistor Q and the RC circuit between the power vd C constitutes, the collector of transistor Q connects the reference voltage output end of pulse-width modulation circuit PWM, or connect the reference voltage output end of voltage comparator, or be connected on the non-earth terminal of adjusting potentiometer.

Switching power supply is to be to exchange input with the AC power, directly obtain high direct voltage through rectifying and wave-filtering, divide two-way to send then, the one tunnel provides power supply for power transfer, another road produces the accessory power supply of 12-25V, as the working power of other element circuits such as width modulation.In pulse-width modulation circuit, produce the adjustable voltage pulse output of a series of pulse widths, this voltage is fed to the input end of power tube, is conducting or cut-off state with the power controlling pipe.Again through the high-frequency transformer isolated buck after output rectification circuit rectification output export feedback circuit simultaneously and send the voltage and the current signal of output back to width that PWM adjusts the output pulse automatically, thereby regulated output voltage.Because level and smooth control circuit carries out zero-based level and smooth lifting to the PWM reference voltage.Thereby can make output voltage form a curve that progressively rises, when the reference voltage of PWM is promoted to ratings, promptly reached stable output voltage.

The utility model enables to be applied to preferably filament circuit by improving the starting response characteristic of switching power supply.Compared with the prior art, the utility model can be courage organic electronic spot silk at when start stable power-supplying during level and smooth pressurized operation, when stopping to start shooting to the rush of current of courage organic electronic pipe, make electron tube always work in high precision voltage stabilizing state, thereby energy-conservation, consumption reduction, reduce failure rate, reduce maintenance workload, reach more than 5 times the serviceable life that on average prolongs electron tube.

The utility model can reduce ripple and the backdrop that produces because of Alternating Current Power Supply simultaneously.

Description of drawings

Fig. 1 is the utility model circuit block diagram.

Fig. 2 is the utility model circuit theory diagrams.

Fig. 3 connects the reference voltage output end circuit theory synoptic diagram of pulse-width modulation circuit PWM for the collector of transistor Q in the utility model.

Fig. 4 connects the reference voltage output end circuit theory synoptic diagram of voltage comparator for the collector of transistor Q in the utility model.

Fig. 5 connects the non-earth terminal circuit theory synoptic diagram that voltage is adjusted potentiometer for the collector of transistor Q in the utility model.

By the following examples.In conjunction with the accompanying drawings the utility model is further described.

Embodiment:

Referring to accompanying drawing 1,2, it is the switching power supply of control circuit that present embodiment adopts with pulse-width modulation circuit PWM, and is the described switching power supply loading amount level and smooth level and smooth control circuit that promotes its reference voltage to ratings of can starting from scratch.

As shown in Figure 1, the switching power supply in the present embodiment is to exchange input with the AC power, and direct current obtains the 300V high direct voltage through rectifying and wave-filtering, divides two-way to send then.One the tunnel for power transfer provides power supply, and another road produces the 12-25V accessory power supply, as the working power of other element circuits such as width modulation.In pulse-width modulation circuit, produce the adjustable voltage pulse output of a series of pulse widths, this voltage is fed to the input end of power tube, with the power controlling pipe is conducting or cut-off state, again through the high-frequency transformer isolated buck after output rectification circuit rectification output, simultaneously, the output feedback circuit is sent the voltage and the current signal of output back to width that PWM adjusts the output pulse automatically, thus regulated output voltage.Holding circuit among the figure is in order to detect output voltage, electric current and input condition, and when voltage and the unallowed exceptional value of electric current appearance design, holding circuit provides control signal, and pwm circuit is quit work, with protection circuit for power conversion itself and load.

Reference voltage in the present embodiment by level and smooth control circuit start from scratch be promoted to ratings the lifting time greater than 10 seconds.Because level and smooth control circuit carries out zero-based level and smooth lifting to the PWM reference voltage, thereby, can make output voltage form a curve that progressively rises, when the reference voltage of PWM is promoted to ratings, promptly reached stable output voltage.

As shown in Figure 2, level and smooth control circuit in the present embodiment is by transistor Q and be arranged on the base stage of transistor Q and the RC circuit between the power vd C constitutes, the collector of transistor Q connects the reference voltage output end of pulse-width modulation circuit PWM, and the length of the voltage rise time that this circuit provided can change in the larger context by the adjustment of RC parameter.Resistance R should satisfy condition: ((VDC-Vbeo)/R)) Ibo, wherein Ibo is the reliable base current required when saturated of transistor Q, smoothingtime is subjected to the influence of Q saturation depth, IC benchmark output current, environment temperature, VDC voltage etc., general C value can make smoothingtime not wait from 10S to 10min between 10u-1000u.

Because the electric capacity both end voltage can not be suddenlyd change, during start, the electric capacity both end voltage is zero, and transistor is saturated leads, and the output of PWM reference voltage is zero by strangulation.Along with the capacitor C charging, the pressure drop on the electric capacity progressively reduces, and makes transistor work in cut-off state, is open circuit between its collector and emitter, and after this, pwm circuit is with its specified reference voltage output.Diode D is in when shutdown among the figure, provides a discharge path to capacitor C, makes level and smooth control circuit get back to state of a control to pwm circuit immediately.

In concrete the enforcement, as shown in Figure 3, the collector of transistor Q is except that the reference voltage output end that can meet pulse-width modulation circuit PWM, and the reference voltage output end (as shown in Figure 4) that can also connect voltage comparator also can connect the non-earth terminal (as shown in Figure 5) that voltage is adjusted potentiometer W.

Claims

1, courage organic electronic spot silk dedicated power supply apparatus, it is characterized in that adopting with pulse-width modulation circuit PWM is the switching power supply of control circuit, and is the described switching power supply setting level and smooth level and smooth control circuit that promotes its reference voltage to ratings of can starting from scratch; Described level and smooth control circuit is by transistor Q and be arranged on the base stage of transistor Q and the RC circuit between the power vd C constitutes, the collector of described transistor Q connects the reference voltage output end of pulse-width modulation circuit PWM, or connect the reference voltage output end of voltage comparator, or connect the non-earth terminal that voltage is adjusted potentiometer W.

2, courage organic electronic spot silk dedicated power supply apparatus according to claim 1, it is characterized in that described reference voltage start from scratch be promoted to ratings the lifting time greater than 10 seconds.