8.3.3.2. Check of the generator electronic oscillograph

The oscillograph allows in a form of a curve of the straightened generator tension precisely and to quickly check its serviceability and to define the nature of damage.

Fig. 8-7. The scheme of connections for check of the generator 37.3701 at the stand: 1 — the generator;
2 — a control lamp of 12 V, 3 W; 3 — the voltmeter; 4 — the ampermeter; 5 — a rheostat; 6 — the switch;
7 — the rechargeable battery

For check attach to a conclusion "30" generators the ampermeter, a rheostat, the switch and the rechargeable battery, as shown in fig. 8-7. Besides, at the G-222 generator connect the plug "15" to the + plug" the rechargeable battery.
At the generator 37.3701 disconnect a wire of the general conclusion of three additional diodes from tension regulator plug "B" and connect the plug "B" to the + plug" the rechargeable battery through a lamp of 12 V, 3 W. Isolate a tip of the disconnected wire that he did not become isolated with a weight. Thus, food on a winding of excitement will directly move from the rechargeable battery.
Turn on the electric motor of the stand and finish the frequency of rotation of a rotor up to 1500 - 2000 min.-1. The switch 6 switch-off the rechargeable battery and 5 establish by a rheostat current of return 10 A.

Fig. 8-8. A form of a curve of the straightened generator tension: I \the generator is serviceable; II \the diode is punched; III \break in a diode chain

Check an oscillograph tension on the generator 30 plug. At serviceable diodes and a winding of the stator the curve of the straightened tension has the sawtooth form with uniform teeth (fig. 8-8, I).
If there is a break in a winding of the stator either break or short circuit in rectifier diodes, the curve form sharply changes: uniformity of teeth is broken and deep hollows (fig. 8-8, II and III) appear.

Fig. 8-5. Scheme of connections of system of the generator 37.3701: 1 — the rechargeable battery;
2 — the negative diode; 3 — the additional diode; 4 — the generator; 5 — the positive diode; 6 — a stator winding; 7 — tension regulator; 8 — a rotor winding; 9 — the condenser for suppression of a radio noise; 10 — the assembly block; 11 — a control lamp of a charge of the rechargeable battery in a combination of devices; 12 — the voltmeter; 13 — the ignition relay; 14 — the ignition switch

At the generator 37.3701 check also tension on the plug "61" or on a tip of the wire disconnected from tension regulator plug "B". These points are the general conclusion of three additional diodes (see fig. 8-5) feeding an excitement winding during the operation of the generator. Tension curve form here too has to have the correct sawtooth form. Irregular shape of a curve demonstrates damage of additional diodes.