DE1281580B - Electromagnetically excited oscillating capacitor - Google Patents

Description

Electromagnetically Excited Oscillating Capacitor The invention relates to an electromagnetically excited oscillating capacitor that is lightweight and safe operation even under poor conditions if there is little space required guaranteed.

Oscillating capacitors are used to measure voltage on direct current sources with high internal resistance used in conjunction with electrometers. Measurements Such high-resistance voltage sources are also used, for example, for monitoring from ionizing radiation. A special use is the use of oscillating capacitors in basis weight measuring devices.

There are oscillating capacitors known, in which almost all for their Excitement seemingly reasonable paths have been taken. So are oscillating capacitors with vibrating membranes, with vibrating tongues, with vibrating scales, all based on the headphone system, and oscillating systems made of permanent or electrodynamic loudspeakers been. -Swing systems, consisting of an iron core suspended in spiders, which is excited by means of a solenoid (polarized and non-polarized systems).

These known systems also work in modified versions Execution as frequency-determining members or entirely above or below them mechanical resonance frequency.

These known oscillating capacitors have particular disadvantages in the fact that the electrode materials used do not have vibrating tongues can be chosen at will. Because the vibrating tongues are controlled magnetically they must be made of ferromagnetic material.

The well-known electromagnetic or electrodynamic drives have the disadvantage that they have a complicated and heavy structure and a Adjustment is difficult.

Other known oscillating capacitors have the disadvantage that the Procedures used by them to adjust the conversion efficiency are cumbersome and is difficult.

With such oscillating capacitors, it is true that in the installed state can also be adjusted, but this is the fixed core of the drive system adjusted, which at the same time changes the inductance of the drive circuit. As a result, the drive currents are different for the same voltage. The effect of force in the non-polarized drive system of such an oscillating capacitor takes place away from the stationary electrode during each amplitude, so that substantially larger drive powers are required in order to achieve a favorable conversion efficiency get. In the case of these known oscillating capacitors, the plate spacing is also determined Adjusted in a way that eliminates the possibility of the surfaces being scratched and can be polluted.

The purpose of the invention is to provide an oscillating capacitor for electrometers to create the. known electrometers due to their universal applicability and greater insensitivity are superior.

This oscillating capacitor is intended for electrometric measuring arrangements are available and easy to assemble, adjust and use, have a high conversion efficiency and also a low susceptibility to failure combine with high stability and have a low weight and space requirement.

The invention is based on the object of making measurements on high-resistance Carry out voltage sources with a high signal-to-noise ratio, for example ionizing To monitor radiation, for example by measuring the voltage at the load resistance of a Ionization chamber, which is a consequence of the chamber current when exposed to radioactive Irradiation changes. This task is performed with an electromagnetically excited, in a housing tightly built-in oscillating capacitor, which is connected to a fixed, An electrode mounted on an insulator and an electrode excited by a drive system Oscillating electrode and is provided with a coupling capacitor, according to the invention solved in that the drive system has an oscillating core, the opposite a fixed core by means of a nut arranged on a guide pin adjustable or adjustable that the drive system by means of an annular body is screwed into the sleeve and adjustable that a fixed Electrode, an insulator, a coupling capacitor electrode, an intermediate ring and a The threaded ring is screwed into the sleeve connected to one another by guide pins and a coupling capacitor can be adjusted using a spring ring.

The excitation of the oscillating capacitor happens on electromagnetic Paths with or without - additional permanent magnets.

The electromagnetic excitation or amplification or the permanent one The preload is provided by a translatable device arranged in the area of the excitation coil Ring magnets achieved.

The magnetic excitation is designed as a pot core, which consists of a upper yoke package, a lower yoke package, a sheet metal cylinder, a stationary one Core and an oscillating core and in which all lines of force are essentially run in the direction of the axis.

The fixed core and oscillating core are made of magnetic soft iron, and the radial surface parts, upper yoke package, lower yoke package and sheet metal cylinder, consist of dynamo sheet.

All components are made on lathes.

The effective air gaps are individual, especially in the dynamic case, adjustable.

The oscillating capacitor is fixed on a base and becomes light operated interchangeably in associated sockets.

The main advantage of the invention is that the conversion efficiency is ornamental of the oscillating capacitor in the dynamic state under oscillographic observation the waveform of the output alternating voltage can be adjusted without the magnetic conditions in the drive system need to be changed. These advantages are emphasized by the fact that they are simple in construction Oscillating capacitor can be achieved.

The invention is to be explained in more detail below using an exemplary embodiment. In the drawing, F i g. 1 shows a sectional drawing of the oscillating capacitor according to the invention, FIG. 2 an effect and principle diagram.

The oscillating capacitor consists according to FIG. 1 from two building units, a sleeve 1 in which an adjustable coupling capacitor electrode 2 and a; fixed coupling capacitor electrode 3 and a main insulator 4 with a fixed Electrode 5 of the oscillating capacitor are used, and a drive system in Ring body 6 with an oscillating electrode 7.

This complete separation of the structural units makes it possible that Adjust the drive system separately in order to then adjust the oscillating capacitor after insertion of the drive system in the sleeve 1 during operation for optimal conversion efficiency to adjust.

The oscillating capacitor is guided in a sleeve 1 made of brass. Of the The measuring space is limited by brass components that are precise and easy to manufacture.

A projection 8 provided in this sleeve 1 carries the main insulator 4, for example made of polytrichlorofluoroethylene, the surface of which is carefully polished is to keep the surface resistance large. This main insulator 4 is held over an intermediate ring 9 by a threaded ring 10. The intermediate ring 9, which is turned slightly conically on the side facing the main insulator 4, has the task of intercepting the main insulator 4 and any temperature-dependent Compensate for changes in thickness. On the threaded ring 10 is an insulator II for the coupling capacitor. The insulator is also made of polytrichlorofluoroethylene, for example manufactured, whose surface resistance is increased by appropriate shaping became.

The angle of the support of the fixed electrode 5 of the oscillating capacitor to the central axis of the sleeve 1 must be exactly 90 ° in order to guarantee that the fixed electrode 5 runs flat to the oscillating electrode 7 over the entire surface. During assembly, the main insulator 4 is assembled with the fixed electrode 5 and coupling capacitor electrode 3. Then the main insulator 4 is inserted together with the intermediate ring 9 in the sequence shown on the guide pins 12 fitted into the threaded ring 10 and the whole thing is screwed into the sleeve 1 with a special key: tightened.

Then a ring nut 13, a threaded bushing 14, a spring washer 15 and the adjustable coupling capacitor electrode 2 on the coupling capacitor insulator ll attached and this plugged onto the guide pins 12. The adjustable coupling capacitor electrode 2 must first be screwed back as far as it will go by turning it to the left> Finally, a protective cap 16 is put on and a union ring 17 with the help .einer Special pliers tightened. The use of a special tool is supposed to be an intervention in the oscillating capacitor from a non-specialist side make it more difficult to a large extent.

The drive system in the ring body 6 is mix an upper cover 18 summarized. The iron connection of the drive system consists of an upper one Yoke package 19 and a lower yoke package 20, an outer iron lock, which consists of two 0.5 mm thick sheet metal cylinders 21 is formed, a stationary core 22 and a vibrating core 23 made of magnetically soft iron. Here is the fixed core 22 fitted into the upper yoke package 19. The upper yoke package 19 and the lower yoke package 20 consist of dynamo sheets which are held together by hollow rivets will.

When assembling the drive system, the two are first plugged into one another Sheet metal cylinder 21 in the ring body 6: inserted. Then the lower yoke package 20 pressed in. A wound coil 24 and the upper yoke package are then placed on this 19 used. The upper cover 18 is then fitted with an upper oscillating plate 25, an upper clamping ring 26 through the countersunk screws 41 and with the oscillating electrode 7 and a guide bolt 27 as well as a nut 31 and an IT washer 32 assembled and screwed into the ring body with special pliers and tightened.

The vibrating core 23 is screwed onto the guide bolt 27 until the lower surface of the vibrating core 23 cuts off the bearing surfaces of a lower vibrating plate 28. The lower oscillating plate 28 is inserted and tightened by a lower clamping ring 29 with the screws 39 and 42, the coil connecting wires being passed through a hole provided in the lower oscillating plate 28. Then the entire drive system can be adjusted.

The ring body 6 is then screwed into the sleeve 1. For that is For example, a fine thread with a pitch of 0.5 mm is provided, which is sufficient Safe adjustment of the oscillating capacitor with a plate distance of about 0.1 mm allowed.

When producing the sleeve 1 and the ring body 6, particular care must be taken to ensure that the fitting cylinder located above the thread is properly guided. The lower side of the drive system is protected against possible contamination when a base 34 is soldered in by a lower cover 38 made of polyvinyl chloride.

After the total adjustment of the oscillating capacitor, a locking ring is made 30 screwed into the sleeve 1 until it is about 1 mm over with its lower edge the end of the thread and the drive system with a locking screw only hinted at 33 specifies.

Finally, the base 34 can be soldered and screwed together.

The base 34 and a holder 35 are expediently provided with a detent formed by the special screws 36 and 37 , which prevents the oscillating capacitor from loosening or falling out of the holder 35.

Since the oscillating capacitor is only made up of rotating parts the production is simplified. The two polytrichlorofluoroethylene isolators can be pressed for larger quantities and the oscillating plates 25 and 28 punched will.

For all critical components in the exemplary embodiment Brass and intended for the less critical steel.

The oscillating capacitor does not require any maintenance and can easily be replaced will. It is stable and can be transported without special protective containers. The operational and measuring voltages are conducted via connections soldered into the electrodes, the are not shown. To achieve the best possible contact between the vibrating membrane and to ensure their supply, a terminal lug 40 of the membranes is provided.

For the main insulator 4 and the coupling capacitor insulator 11 can a ceramic material can also be used with good success.

The F i g. 2 shows the basic structure of the magnetic drive system.

The vibrating electrode 7 is connected to the upper vibrating plate 25, the vibrating core 23 and the lower oscillating plate 28 firmly connected. An alternating voltage is applied to the coil 24 applied, the vibrating core 23 and with it the upper vibrating plate 25, which lower oscillating plate 28 and the oscillating electrode 7 in the yoke, which consists of the upper yoke package 19, the lower yoke package 20 and the sheet metal cylinder 21, an oscillating movement against the fixed core 22. Above the oscillating electrode 7 is the stationary one Electrode 5 can be seen.

Claims (7)

Claims: 1. Electromagnetically excited oscillating capacitor tightly installed in a housing, which is provided with a stationary electrode mounted on an insulator and an oscillating electrode excited by a drive system as well as with a coupling capacitor, characterized in that the drive system has an oscillating core (23 ) which is adjustable or adjustable with respect to a stationary core (22) by means of a nut (31) arranged on a guide bolt (27) , so that the drive system is screwed into a sleeve (1) and adjustable by means of an annular body (6), that a fixed electrode (5), a main insulator (4), a coupling capacitor electrode (3), an intermediate ring (9) and a threaded ring (10) are screwed into the sleeve (1) and a coupling capacitor ( 2, 3) can be adjusted using a spring ring (15). 2. oscillating capacitor according to claim 1, characterized in that the excitation is electromagnetic with or without additional Permanent magnets takes place. 3. oscillating capacitor according to claim 1 or 2, characterized characterized in that the electromagnetic excitation or amplification by a outside in the area of the excitation coil, for example with the omission of a sheet metal cylinder (21), translatable ring magnet takes place. 4. oscillating capacitor according to claim 1, 2 or 3, characterized in that it is excited by a pot core which consists of an upper yoke package (19), a lower yoke package (20), the sheet metal cylinder (21), the stationary core (22) and the oscillating core (23) and all lines of force are substantially axial. 5. oscillating capacitor according to one of the preceding claims, characterized in that the lines of force in the cylindrical axial parts, the fixed core (22) and the oscillating core (23) made of magnetic soft iron and in the radial surface parts, the upper yoke package (19), the lower yoke package (20) and the sheet metal cylinder (21) made of dynamo sheet. 6. Oscillating capacitor according to one of the preceding claims, characterized in that all components are made as turned parts. 7. Oscillating capacitor according to one of the preceding Claims, characterized in that the air gaps are individually adjustable. B. Oscillating capacitor according to one of the preceding claims, characterized in that that the oscillating capacitor is attached to a base (34) and is easily exchangeable can be operated in associated versions. References Considered: U.S. Patents No. 2,483,981, 2,632,791, 2,764,732, 2,867,758.