DE1040072B - Method for the delayed generation of pulses, in which the delay time is proportional to the time interval between two external pulses - Google Patents

Description

GERMAN

Many methods are known for building delay relays on a mechanical basis. It will either clockworks are used for longer switching times or for shorter delay times specially designed anchors are used. While with clockwork relays the delay times in one Interval of 1:20 are adjustable, these can be in the case of relays with a special winding or armature, generally only for one delay value build. One is forced to switch to electronic relays.

The known flashing circuit shown in Fig. 1 can be used as a delay circuit. The capacitor 1 (amount C) is charged via the resistor 2 (amount R) from the battery 3 with the terminal voltage M ₀ (3) when the switch 4 is closed. As soon as after the exponential time function

U =:

l_ \

e ^RC I

(1)

u reaches the ignition voltage M ₂ of the glow gap 5 connected in parallel to the capacitance, ignites it and causes a brief current surge in the (low-resistance) consumer 6. The time between the start of the switching process at 4 and the ignition of the tube is determined by the time constant RC if the battery voltage is constant. This electronic delay relay can only be used in the manner described if the duration of the primary switching process is at least equal to the delay time. Often this condition will not be fulfilled, but it will be required that the relay also work if the primary process is only a short impulse. To meet this requirement, an arrangement working with two discharge tubes is known in which a capacitor is located in the lattice circle of one tube, the charging of which controls the ignition process. This capacitor is in turn charged or discharged through a second tube. The second tube in the charging circuit is ignited by the incoming pulse using a grid control. When a certain state of charge is reached, the discharge disappears by itself. The delay time can be changed by changing the time constants of the charging circuit. This arrangement can also be switched with short pulses.

The invention sets itself an object that goes beyond the known delay relays of repeating a time interval (Ji) given by two external pulses on a certain scale. Fig. 2 illustrates the task. From the two external pulses shown in Fig. 2/1 and 12, method for delayed

Generation of impulses,

where the delay time is proportional

the time interval between two

External impulses is

Applicant:

German Federal Post Office,

represented by the President

the Central Telecommunications Office,

Darmstadt, Rheinstr. 110

Dipl.-Ing. Willi Menzel, Geneva (Switzerland), has been named as the inventor

which include the time period At , a new pulse Ix is to be generated in such a way that the time period At _x limited by / 2 and Ix is proportional to At .

This object is achieved according to the invention in that the first external pulse is gated a high-frequency generator with a downstream rectifier and time constant element, the grid bias a gas discharge tube, while the second pulse with simultaneous blocking

tion of the grid voltage generator by gating a second high-frequency generator with downstream rectifier and time constant element provides the anode voltage, with after Once the gas discharge tube has been ignited, a pulse derived from the discharge current impulses the anode voltage generator locks.

The invention is explained in more detail below using an exemplary embodiment.

The circuit arrangement according to Fig. 4 consists in principle of a gas discharge tube E, the grid voltage of which is supplied by a high-frequency generator A, the anode voltage of which is supplied by a high-frequency generator B after each rectification and storage via a time constant element.

Both generators have the same basic circuit, they each consist of a tube 1 (1 '), a resonant circuit 2 (2 ') and a grid combination 3 (3') and a bias divider 4 (4 '). Above

S09 640/195

The high-frequency voltage is applied to each capacitor 6 (6 ') to a rectifier 7 (7 ') and from this via a charging resistor 8 (8') to one Charging capacitor 9 (9 ')

The rectifier 7 coupled to the generator A is polarized so that it charges the capacitor 9 negatively. The capacitor 9 is parallel to a resistor 10, which is high compared to the charging resistor 8, on the grid of the gas discharge tube E, thus dividing the grid bias voltage for the gas discharge tube.

The rectifier T coupled to the generator B only allows the positive half-waves to pass and accordingly causes the capacitor 9 'to be positively charged, which is connected to the anode of the gas discharge tube E via the working resistor 11, i.e. provides the anode voltage.

As a result of the bias applied to them, both generators only vibrate after one has acted positive momentum on the grid. They then oscillate in the even after the start impulse has ended C operation continues until a negative pulse interrupts the oscillation again.

The pulse trains received from the outside are the two generators with each different Polarity (e.g. by a phase reversal stage in the pulse feed line of a generator).

To solve the problem according to the invention, the two generators now work together in the following way: The first pulse / 1 of a pulse series with alternating polarity hits the grid of tube 1 of generator A with positive polarity. This starts to oscillate, so that the charging capacitor 9 is negative being charged. The generator A works until the arrival of the second transmission pulse / 2, which, due to its negative polarity, blocks the generator A and thus interrupts the negative charging of the capacitor 9.

For the generatori? had the pulse 1 1, because it is present there with negative polarity, no effect, the pulse / 2, however, causes the generator to oscillate, so that the capacitor 9 'provides a positive anode voltage for the gas discharge tube E. As soon as the ignition voltage is reached at the capacitor 9 ', the gas discharge tube ignites and generates the working current surge in the low-resistance consumer 11, which can be used for the desired purpose by known downstream elements. At the same time, however, the negative voltage peak generated by the discharge of the capacitor 9 'is passed to the grid of the tube V of the generator B via a pulse return line consisting of a capacitor 13 and a high-frequency choke 14. As a result, the grid bias is momentarily so strongly negative that the oscillation stops and in this way no further charge is fed to the charging capacitor.

Only a new positive pulse via the capacitor 5 on the grid of the tube 1 'of the generator B triggers the charging process again.

The generator B is started by the pulse / 2 of the alternating pulse series and, as a result of the ignition pulse feedback , is blocked again immediately after the ignition of the gas discharge tube E , while the generator ^ is started by the pulse / 1 and blocked again by the pulse / 2.

For the time between the effect of the start impulses and the ignition of the gas discharge tube E , on the one hand the dimensioning of the i? C element 8'-9 '(generator B), and on the other hand the level of the grid prestress, which in turn depends on the dimensioning of the i? C-link 8-9 (generator A) depends.

The following consideration applies to the dimensioning of the i? C elements: It is well known that the beginning of the Approximate the exponential function by a straight line. In Fig. 3 an example is shown that accordingly must be modified if greater demands are made on the straightness. The exponential function shown in (1) works with the approximation assumed in the example in Fig. 3, straight line 1 over in

0.8

This approximation is valid up to i = 0.6 RC. For greater accuracy requirements, straight line 2 in Fig. 3 applies, which can be used from 0 <Ξ t <Ξ 0.3 RC. The fimction equation of the straight line is here

u "= U _n —-— t. RC

The straight line 3 in Fig. 3 applies to even higher demands on linearity. It applies in the range 0 <^ i <; 0, l RC and obeys the equation

M "=

-t.

RC

In general, if you move within what is considered to be sufficiently linear:

UU _n

K
IiC

-t.

In this function only one value of u is of interest, namely the ignition voltage for a certain setting of the gastriode. For the time t _z in which the ignition voltage u _{z is} reached, the following applies:

u _z RC

u _n K

The delay time is therefore directly linearly dependent both on the time constant RC and on the ignition voltage u _z , provided that the charging voltage u ₀ remains constant.

If a large range of t is to be used, one must make full use of the shape of the exponential curve and move into the regions with a low gradient.

Taking into account the consideration of linearity, the time t _z between the last received pulse / 2 and the generated pulse is proportional to the time period At given by the distance between the two external pulses, given the appropriate dimensioning of the time constant elements.

According to equation (3), the time span to be formed between / 2 and Ix is proportional to that between / 1 and 12. The proportionality factor essentially provides the size of the time constant in the anode circuit. This, too, can be determined by a further impulse according to a further development of the inventive concept. For this purpose, the direct voltage applied to a charging capacitor can be used to control a tube serving as a charging resistor. According to equation (3), the relationships between R and t for other linear relationships are also linear.

Claims (2)

Patent claims: 1. Method for the delayed generation of pulses, in which the delay time is proportional tional is the time interval between two external pulses, characterized in that the first external pulse provides the grid bias of a gas discharge tube (E) by gating a high-frequency generator (A) with a downstream rectifier (7) and time constant element (8, 9), while the second pulse simultaneously Blocking of the grid voltage generator (A) by switching on a second high-frequency generator (B) with downstream rectifier (T) and time constant element (8 ', 9') provides the anode voltage, and that after ignition of the gas discharge tube (E) a pulse derived from the discharge current locks the anode voltage generator (B). 2. The method according to claim 1, characterized in that the gas discharge tube is used as the charging resistor an electron tube is used, the grid bias voltage of which is also provided by a generator controlled by the two external pulses is supplied so that the delay time due to impulses coming from outside without intervention in the arrangement can be determined automatically. Considered publications:
German patent specification No. 681 201. 1 sheet of drawings