DE1541504A1 - Protection device for the output stage of a radio serider - Google Patents

Description

Dt.Hertett.eekeI »PH» 1355

no. IHN- 1355
22.Augu _S t 1966

"Sohutvorriohtung for the exit ·· tuf β« ine · FunJujenders "

The invention relates to a device for soothing the translator (transistors) of the output stage of a
usually by service or by amateurs used transmitter «

Random events, speed up the usual operation
A solobe "senders can die, like s * B * an interruption or an earth connection dee antenna circles" impaired or interrupt the normal SaergiesufUto the Aueesncsstufe "η the an" teent "!% ■ Receive ive direct ron 4e * fender with the A" antenna

009814/01 * 3

PHI 1355

transmitted waves and the reflected, interrupted or deregulated from the · !! Antenna on the transmitter surüok transmitted waves causes the occurrence of standing waves and overloading of the transistor (s) at the output stage of the transmitter thereby destroying the transistors

Bs' is thus necessary to pass the transistor (s) through a «device su sohütsen that immediately when the error occurs effective

The protective device according to the invention contains only semiconductor parts without contacts, which are controlled by the output of a directional antenna coupling and the signals extracted in the event of a mismatch in the antenna impedance, the effect of the output stage regulate the previous stage

lach the invention will dl · protection device for the

The output stage of a radio transmitter is identified by the fact that it parallel alt the transmitter »wipe the one preceding the output stage Stage and a directional antenna coupling and contains a first semiconductor element which is directly connected to the output of the coupling element is connected and when a rising voltage occurs at the output the line of a second semiconductor element controls whose output directly »it de« control organ of the output stage previous stage is connected in such a way that this is always It is blocked "if the conductivity of the" second semiconductor organ suniaat

Oa su vMNMi & wtf da ·· furinf * change to Ipanraaijpi · » as a result of a 8peisMp> niiuwgas »aw * akuaf ua4 nioht as a result of a»

14/0702

BATH ORIGINAL

IW 1355

BUfIl lie disturbance of the antenna circuit ·· dl · device near the Invention effective "" makes this device "contained in the voltage regulator," dM dl "voltage" o output of the second half "it" ror ~ gone within. b # «timater Qren« en stabilized and the exchange rate geohlos-

I 1

sen will «if the change in management affects this ··« wide body » etimaten 3ohwellewert covered »

The first and the wide semiconductor organ can be advantageous are formed by translators that are controlled at the base * while the voltage regulator can be a Zener diode, whose working point lies on the tertiary part of the characteristic curve

Bine advantageous form of the sun hat prowess According to the invention, it contains a first transistor, the base of which is connected to the output of the directional coupling and who is of a solo type and available on the sur standing voltages is fed in such a way that it la normal operation of the transmitter is somewhat conductive, i.e. when no voltage from the coupling element is effective at the input The first transistor is directly connected to the base of a wide transistor and these two electrodes are connected to the supply voltage via the same resistance, so that the Collector currents of the first transistor via this resistor A change in potential at the base of the "wide transistor" causes. Between the slitter and the collector of the "wide transistor" is parallel «in · Zener diode, which is connected to« loh in H «lh · with a Resistance «between earth and high voltage kleome is connected, whereby dl · Diod · and the resistance a · Br & Ok · form «Di · Polarity The diode connection in this bridge is such that it is connected by a

PH »1355

Reverse current flows through «whose mean value corresponds to a working point on the vertical branch of the characteristic I. - f (V.), Where the reverse voltage I. as a function of Reverse voltage V. is plotted, i.e. in a range close to constant potentials in spite of the relatively large changes the output voltage) so that the diode works as a voltage regulator can be. The potential of the emitter of the second Traneis gate will stabilized in this way and in normal operation, it corresponds to a low current that transi tor durohf Hess ends when tension occurs from the coupling parliament at the base of the first transistor increases

The first and the second transistor form common elements and the Zener diode, the hat device through the emitter of the A wide transistor with the base of the control port of the transmitter is connected, the mean potential of this base thus being equal that of the emitter mentioned is * The potential of the collector and that of the emitter of the control transistor are taken for granted chosen in such a way that this transistor is correctly conductive during normal operation and provides the required gain.

In the event of a disturbance in the antenna circuit, the Voltage aa input of the first transistor block this and its Suppress collector current * The voltage drop across the collector circuit of the first transistor and the base of the second transistor common resistance decreases, so that the potential difference «Wipe the slitter and base of the second transistor · changes in such a way that that · the transistor current can take up to the saturation point. Of the The emitter-collector circles of the "wide transistor" then form one

0 0 9 8 U / 0 7 0 2 _BAD

. 5 - ■ ^{PHH 1355}

Course base for the Zener diode »which is connected to the terminals · There is a change in the« base potential of the control transistor gate of the transmitter »whereby the polarity of this change controls the transistor in the blocking direction» whereby the input voltage level aw output stage of the transmitter is proportionally reduced »bo that this stage is protected from the detrimental effect of disturbance of the antenna circuit.

The invention is explained in more detail on the basis of the drawing.

The part of the transmitter shown schematically in the single figure contains a transistor T. of the NPN type in the control stage of the transmitter "a coupling circuit 11" between the transistor T. and the transistor T ₁ . also the npn type »which forms part of the initial stage and represents the most honored part» and the structure 12 of the antenna circuit with capacitors »coils and switches.

A directed coupling element 13 »through which the Antenna 17 is connected to the transmitter circuit »is a well-known one Type; different constructions are available as Accessories for coaxial radio frequency cables. The coupling element contains s.B. a conductive bond connected to earth at one end, that is inductively and capacitively connected to the inner line »and a diode and a detector capacitor. If there is a reflected wave as a result of a malfunction or a disturbance in the antenna circuit greater intensity occurs in the inner line of the coupling element » This replaces an oleic voltage at the terminal 14 of the coupling element · 13 »whose value depends on the intensity of the reflected Wave changes. The DC voltage occurs at the input terminal 16 of the

0098 * 4/0702

- 6 - · PH »1355

Sohut «device 1θ on.

In the illustrated embodiment, the positive terminal is the voltage source common to the transmitter and the protective device connected to earth N *

The transistors T. and T _{2 of} ^the protection device are here of the pnp type. The base 20 of the transistor T. is directly connected to the input _{terminal 16 and the emitter 19 is connected to ground N) a polarization resistor R 2 of} high value between the Öaeis 20 and the collector 21 limits the base current of T. and brings the base potential of this transistor to a negative, almost zero value. The base 22 of the transistor T _g is directly connected to the collector of T. ^ so that the resistance R "by negative feedback, the base potential of T stabilized, which transistor thereby is less sensitive to tolerances of the transistor T ₁ due Aelterung and selecting" The collector 21 of T ₁ is connected to the negative pole of the supply voltage source via a resistor R. of a few thousand ohms. The collector _{atom of T 1} I, which durohflies the resistance R., is low. The resistor R, is also in the base circuit of T ₂ as a result of the connection between base 22 and collector 21. The passage of the collector current from T ₁ through the resistor R-. creates a voltage drop which sets the potential of the base 22 of T ₂ to a slightly negative value with respect to the emitter 23, thereby determining the low initial current of T ₂ . The collector 24 of T ₂ is connected directly to the negative terminal of the supply voltage source. A Zener diode Z is connected between the emitter 23 and the collector 24 of the transistor T ₂ and its anode is connected to the minus terminal of the supply voltage. ^l

3Γ V BATH ORIGINAL

- 7 - PH »1355

The output terminals 25 (emitter 23) of the protection device 18 is at K with the input of the control stage via a high frequency inductivity L with vemaohlSigbarem, incense resistance connected, which is bridged by a capacitor C, L, C, the does not affect the effectiveness of the device »

In normal operation, the potential of the Baalβ 26 of the transit gate T, is set to a negative value, which depends on the value of the resistor R ₁ and on the characteristic of the associated diode connected in series between the negative terminal of the supply voltage and earth N »Der The voltage drop across the resistor R. depends on the current I _n , which flows through the resistor and is equal to the sum of the currents (l ~, + I «ß ^" * "* z ^ ^{β8 ElIli} - ' ^b ' ^{tere from τ} ρ * ^Λθβ 2 ^aBialcre: '- ~ see from T, and the diode 2 is.

A decrease in the sum I ₂ ^ ⁺ ^ o *: as a result of a small change in the supply voltage increases the value of the potential at point K and thus the voltage value at the terminal of Zi I "increases, whereby the total or partial decrease in the sum of the two other current _{parts I 0 is} balanced, so that the initial value

^R 1
the potentials at point K is reached again.

Conversely, an increase in the sum I ₂ I ⁺ * 26 ⁶ ^ ^{ηθ leads to a} decrease in the potential at point K, which in turn leads to a decrease in

I ₇ follows, as a result of which I _R «can again reach an average value

. 1

and the potential at point K can come closer to the initial potential *

This only applies to small changes in current.

The diode Z acts as a voltage regulator as long as the current I _{2 has} a low value and thus as long as the transmitter is normally active.

It is now assumed that there is a disturbance in the antenna circuit it causes the directional coupling element 13 to produce a scattering

0098U / 0702

BATH ORIGINAL

1S41S04

voltage pOfclUrer polarity in b «« u (j on earth Iu detect what voltage is going to the input 16 of the protective device outside * Dan potential of the Baal »SO the translator T., that something is negative in relation to the de * emitter »19 then becomes positive, whereby the transistor dee pnp type is blocked. The current flowing through the resistor 3fL decreases, to that the potential of the baei · 22 de« tranei · tor · T _{g is} reduced. The potential difference ewisohen dea slitter and the. Baeie in this transistor takes eu, which means a considerable increase in de · Bhiitteretroaui I ₂ occurs * the infolgedeeeen occurring voltage · case cross the resistor R. erteugt a potential case Uk point K, which in this case not by the Diode Z can be compensated because the resulting decrease in its current · I "is independent of the considerable increase in I", "The diode Z is practically closed by the Eaitter collector circuit of the transistor T ₂ "

The decrease in potential at point K reduces the voltage under the base 26 and the baitter 27 of the transistor T. the minucleae of the supply voltage) so that this transistor is blocked and in this way the further stage T _{5 is} isolated.

It should be noted that the antenna coupling element 13 is a Supplies voltage which is proportional to the disturbance i «t, dl but at to a starred distribution proportional to "it de" su transferred Voltage level is. Under no circumstances can the protective device break the VIr * kitng de "Influence the transmitter if the adaptation ratio · ·· is correct«

BATH

0098U / 0702

- 9 - PHH 1335

Bb is therefore possible to use the Sohut device after the Invention with a display device for the correct division of the Antennenkreieee »u koabinieren. One measured value is sufficient for this purpose 15 bit movable frame of sufficient sensitivity »wipe the output H of the coupling elements «11 and earth K au held under <* iger connection of a resistor R, in series with the measuring 15

The correct pitch of the antenna circle and the Quality of the adaptation of the impedans of the various organs of the Circle are evident from a minimal or no deviation from the «Mesawerkee 15 ·

The following Binselteilet T ₁ t AP 114 Sj I 1.2 kOhm SpeiBeapensioni 24 T T ₂ t AST Π B ₂ t 4? O kOba Keaswerk 15 «Sensitivity 30 μΑ Z ι 12 Z 4 R. ι 6.8 kOhm R, t 1.5 kOhm

SelhetverstlndLlioh can be equivalent through Srsats Some variations of this embodiment shape are designed within the scope of the invention.

BAD QRK5WAL

AROUND. U- / Q?

Claims (2)

Patent application ι Protection device for the output stage of a punk bender, characterized in that the device is switched on in parallel with this transmitter between ± bt of the output stage and a directional coupling element connected to the antenna and that it contains a first semiconductor element that directly is connected to the output of the «coupling element and, when a voltage occurs at this output, controls the line of a disputed semiconductor element, whose output controls directly with the control element of the stage preceding the output stage» so that this stage is blocked when the line of the next Semiconductor organs «unimat. 2. Protection device according to claim 1, characterized in that it contains a voltage regulator "which stabilizes the voltage at the output of the second semiconductor element in the event of fluctuations in the line that are less than that which occurs in the event of a disturbance in the antenna circuit, which voltage regulator is subject to change of course" , if the conduction of the second semiconductor organ exceeds a certain threshold value * 3 · Protective device according to claim 1, characterized in that the first and the "wide semiconductor organ" are formed by the transit gate, which are actuated as the base, and that the spa regulator is formed by a Zener diode, with a barrier and Supply voltage are chosen in such a way that the "Ifcr working point" if the vertical part of their characteristic line is "which" represents "a function imr BSokvirtospsjnsaa" 009814/0702 4 · Sdletworiloatuaf naoa claim 1 »thereby gekennieioanet» that "ie elate" contains the th transistor, dee "en Baals" it de "Aas ·· Gang of the Sopplungeeleeieniee connected let and fed in this way that «er la normal operation of the transmitter» is about * conductive and that «la« reiter Tranalstor is planned, the BuIa directly old the output of the first transistor is connected, the connection point the base and this output are connected to the supply voltage via a resistor »whereby a Zenerdlede ewiaohen de« The emitter and the «collector of the» transistor are connected lsi and the output of the latter alt is connected to the base of the transmitter's 3 expensive traneis sector. 5 · Protective device according to claim 1 »characterized in that a measured value is switched on from the directional coupling element and Krde (between the output of the directional coupling element and Krde ₎ . BATH 0098U / 0702 Empty soap