English translation
Adjustment Instrument for Polarized Relays ON 280 34
This document is an English translation of the original German-language manual published by MEDA.
Contents
- Technical Description … 3
- Technical Data … 3
- Adjustment of Polarized Relays … 4
- Parts List … 6
1. Technical Description
The correct function of the MEDA-T differential analyzers depends on the precise adjustment and setting of the polarized relays used in the computing amplifiers and control circuits of the computer. Since the settings of the polarized relays change during computer operation, regular checks must be carried out and the relays replaced or readjusted if they no longer correspond to specifications. The adjustment instrument ON 280 34 is used to check the setting of the polarized relays; this instrument belongs to the computing equipment MEDA 41 TA. For the MEDA 21 TS computer, the adjustment instrument ON 280 34 is supplied as a special-order item.
The adjustment instrument for the polarized relay allows the relative overdrive time (Überfallzeit) and the symmetry of the relay to be checked in accordance with the deflection on the calibrated scale of the measuring instrument. In addition, the instrument is equipped with sockets for connecting an oscilloscope; using the oscilloscope display, the quality of the relay under test can be assessed optically with regard to the dynamic behavior of the contacts (incomplete touch, flutter, bounce, etc.). The relays are fed during testing from either a built-in source or from a square-wave voltage source from the computer’s rear; for this purpose, the adjustment instrument is connected to the computer’s terminal block at the rear, where the square-wave voltage from the power supply module FSQ-2 is tapped. The procedure for adjusting the polarized relay is described in Section 3.
The tester for the polarized relays ON 280 34 is housed in a portable metal enclosure; its complete circuit is shown in Appendix 8.
2. Technical Data
| Parameter | Value |
|---|---|
| Type of measurement | Relay symmetry, relative overdrive time (Überfallzeit) |
| Excitation voltage | Sine voltage (own), Square-wave voltage (external) |
| Power supply | 220 V, 50 Hz |
| Dimensions (H × W × D) | 225 × 250 × 150 mm |
| Weight | 3.26 kg |
3. Adjustment of the Polarized Relays
As a prerequisite for the correct function of the DC computing amplifiers (computing modules TZP-1, TZP-3, 4, 5), only correctly polarized A 4g/03/XX/V relays (modified HL 100 18 relays) may be installed. The correct adjustment of the polarized X 4g/03/XX/V relay is carried out at regular prophylactic checks of the computer (1× monthly) using the adjustment instrument ON 280 34. The adjustment of the polarized relay A 4g/03/XX/V proceeds as follows:
a) The adjustment instrument is connected to the mains and the connecting cable of the adjustment instrument is plugged into the terminal strip of the test instrument (labeled “AUSSENREGUNG” – VNEŠN. BUZ.) and the socket K 1 at the rear of the computer is plugged in. The socket labeled “OSCILLOSCOPE” on the front of the adjustment instrument is the vertical input of the oscilloscope KFi2ik T 656, etc.
b) The protective cover of the instrument’s relay is removed and the locking screws of the contacts are loosened somewhat to allow the adjusting screws to be tightened freely.
c) The mains switch of the adjustment instrument is switched on, the switch “ERREGUNG” (BUZENI) is set to the “AUSSEN” (VNEŠ.) position, and the “POLARITÄT” (POLARITA) switch is set to the center position. Pressing the pushbutton “ABFALLZEIT” (DOBA ODPADU) sets the potentiometer “EINSTELLUNG 100 %” (NAST. 100 %) so that the pointer of the measuring instrument points to the 100-marked line (scale is 100 % total). During continuous measurement, this setting must be checked from time to time.
d) First the rough adjustment is carried out. The “POLARITÄT” (POLARITA) switch is placed in the outermost position where the pointer of the measuring instrument deflects positively. When the indicator lamp “KONTAKTKURZSCHLUSS” (ZKRAT KONTAKU) lights up, the adjusting screws are tightened with a steel pin inserted into the openings on the screw heads. The rough adjustment is observed on the oscilloscope. The relay is adjusted accordingly so that the waveform on the oscilloscope corresponds to Diagram 8.1. The rectangles must be symmetrical — the relay must not oscillate — both overdrive times (Tp and Ts) must be identical and their duration must correspond to approximately 1/20 of the closing time Ts, Ts’. Oscillation can often be eliminated by cleaning the contacts and the relay contact surfaces (use clean paper without fibers when cleaning, so that no glue remains).
e) The fine adjustment of the polarized relay is carried out using the adjustment instrument or its measuring instrument. The “POLARITÄT” (POLARITA) switch is placed in the outermost position where the instrument pointer deflects in the direction of scale, indicating the percentage relay closing setting (the full range of the scale is 100 %). By turning the adjustment screws, the relay is set to the null deflection of the measuring instrument, with the indicator lamp “KONTAKTKURZSCHLUSS” (ZKRAT KONTAKU) not lighting up. Then the “POLARITÄT” (POLARITA) switch is placed in the center position, where the measuring instrument indicates the relay closing time in % of the total duration of the entire work cycle. The duration of the closing time should be set to 95 %. During the closing time setting, the relay symmetry and overdrive time are observed on the oscilloscope.
f) After completing the fine adjustment, the locking screws of the contacts are tightened carefully and covered with the protective cover. After attaching the protective cover, the final check of the symmetry setting and overdrive time per point (e) is carried out.
4. Parts List
| Part | Designation | Order Number |
|---|---|---|
| R 1 | Shunt resistor | 1 kΩ ± 1 S/1 W |
| R 2 | Shunt resistor | 1 kΩ ± 1 S/1 W |
| R 3 | Shunt resistor | 1 kΩ ± 10 kΩ/1 W |
| C 1 | Electrolytic capacitor | 50 µF/12 V |
| P 1 | Slide potentiometer | 5 kΩ/linear |
| E1, E2 | Indicator lamp | 6 V/0.05 A |
| PF 1 | Blade fuse | 0.6 A/250 V |
| K | Socket | 41 GG/21-34 |
| M | Measuring instrument | DKR 5-100 µA |
| TR 1 | Transformer | GR 100 kΩ |
| T 1 | Push button | 2 FK 461 05.00 |
(Oscilloscope waveform diagram 8.1 appears on this page showing the relay contact timing waveform.)
[Translation covers all 6 pages; this is the complete document.]