How to connect a single-phase motor. Vertical drilling KD 50 u4 operating principle

To make two-wire lines, you need to take brass or copper wire with a diameter of 1.5-4-2 mm. The narrow line is closed by node G (Fig. 5), which is made in the following way. A matching device made of tubes with a diameter of 10 mm is connected to the narrow line. At one end of the tube matching device closed to each other with metal strips and mounted on the wall or roof of the house near the input of the cable going to the TV (the ends need to be strengthened at such a height that the antenna can be easily adjusted, but at the same time the line cannot be accidentally damaged).

The cable going to the TV (preferably RKZ type) is connected to the matching device through a balun. The role of the conductors of the balun is performed by the shielding braids of the RK-3 cable sections, the ends of which are short-circuited on one side and connected to the tubes of the matching device on the other. The location of this connection should be determined experimentally using the successive approximation method. This can be done this way: by first installing

size L2=--p, where Jasr is average

wavelength of that television channel, the reception of which is provided for, achieve the best image reception by first changing the size Lx by moving the clamps of the balun along the tubes of the matching device, and then changing the size L2 by moving the short-circuiting strips along the shielding braid of the cables of the balun. This operation should be done two to three times. Having chosen the best one from various setting options, the clamps and strips are tightly secured, and the exposed parts of the RK-3 cable are insulated to protect them from moisture. To tune the antenna, you can also change the length of the matching device by moving the bars that short-circuit the tubes of this device.

The described antenna system is quite bulky, and therefore care must be taken to ensure its rigidity. In Fig. 7, o and 7, b show one of the options for securing the system. Guys give the device the necessary stability. Some of

them (shown in the figures) need to be separated by insulators, placing the latter relative to each other

at a distance smaller than

(Yamin is the minimum wavelength of the operating range of the antenna). Attention should be paid to strengthening node B with a guy rope, preventing excessive sagging of wide supply lines and freeing them from mechanical loads. The guy rope must be attached to the lines in node B through an insulation board without disturbing the symmetry of the power system.

The height of the mast on which the antenna system is located should be selected so that the center of the system is higher than objects (buildings, trees, etc.) located in the direction of the television center for 1.5-2 km. The width of the main lobe of the antenna system's radiation pattern at half power level is approximately 25°. This circumstance places increased demands on the alignment of the antenna in a given direction. It is undesirable for the maximum deviations from the direction of the telecentre to exceed ±.5°.

ELECTRIC MOTORS PLANT "ELFA"

Electric motors produced by the Vilnius Elfa plant are widely used in many household electrical appliances and tape recorders. counting and writing machines. Over the past year, the plant has been working on the production of more than twenty types of asynchronous electric motors for various purposes.

In Fig. 1 shows dimensional drawings of the most common asynchronous single-phase low-power electric motors of the K.D, DAO, DKhM, KDR and DKS types. The main parameters of these electric motors are shown in table. 1, and their dimensions in table 2.

An electric motor with a squirrel-cage rotor and a DAO-type starting winding (Fig. 1.6) is designed to drive household washing machines and other electrical appliances. The electric motor connection diagram is shown in Fig. 2.

Electric motors of types DXM-3 and DXM-5 (Fig. 1, c) - asynchronous, single-phase, with short-circuited rotor

torus and starting winding of built-in design. They are designed to drive the compressor of domestic electric home refrigerators. The connection circuit for a DXM type motor is similar to the connection circuit for an electric motor of the DAO type (rns. 2).

Electric motor type KD-2 (Fig. 1, o) is an asynchronous single-phase with a squirrel-cage rotor, capacitor, used to drive the tape drive mechanism of a tape recorder. The engine switching diagram is shown in Fig. 3.

The electric motor '™ na KD-P (Fig. 1, a) is an asynchronous single-phase, capacitor. The rotor of this motor is made with an open squirrel cage, which allows for a soft characteristic. The engine is designed to drive the tape drive mechanism of sound recording equipment for winding and rewinding magnetic tape. The engine switching diagram is shown in Fig. 4.

Electric motor KD-30 (Fig. 1, a) - asynchronous, single-phase, capacitor, short-circuited

L. Tsyganova

rotor, designed to drive cash registers of the KI and KO types. The motor connection diagram is shown in Fig. 5.

The electric motor KD-3.5 (Fig. 1, o) is an asynchronous, single-phase, capacitor, with a squirrel-cage rotor, designed for operation in sound recording equipment at ambient temperatures from 5 to 75 ° C. The engine switching diagram is shown on the RNS. 6.

The electric motor KD-25 (Fig. 1, o) is an asynchronous, single-phase, capacitor, with a squirrel-cage rotor, designed to drive a band puncher and an EP electrofiled typewriter. The engine switching diagram is shown in Fig. 7.

Electric motor KD-50 (Fig. 1, c) is an asynchronous single-phase, capacitor, with a squirrel-cage rotor, can be used to drive an oscilloscope of type N102 and N105. The engine switching diagram is shown in Fig. 8.

Electric motor KD-50S (Fig.!, a) - asynchronous, single-phase,

Most often, our houses, plots, and garages are supplied with a single-phase 220 V network. Therefore, equipment and all homemade products are made so that they work from this power source. In this article we will look at how to correctly connect a single-phase motor.

Asynchronous or collector: how to distinguish

In general, you can distinguish the type of engine by a plate - a nameplate - on which its data and type are written. But this is only if it has not been repaired. After all, anything can be under the casing. So if you are not sure, it is better to determine the type yourself.

How do collector motors work?

You can distinguish between asynchronous and commutator motors by their structure. The collectors must have brushes. They are located near the collector. Another mandatory attribute of this type of engine is the presence of a copper drum, divided into sections.

Such motors are produced only single-phase; they are often installed in household appliances, as they allow you to get a large number of revolutions at the start and after acceleration. They are also convenient because they easily allow you to change the direction of rotation - you just need to change the polarity. It is also easy to organize a change in the rotation speed by changing the amplitude of the supply voltage or its cutoff angle. That is why such engines are used in most household and construction equipment.

The disadvantages of commutator motors are high operating noise at high speeds. Remember a drill, an angle grinder, a vacuum cleaner, a washing machine, etc. The noise during their operation is decent. At low speeds, brushed motors are not so noisy ( washing machine), but not all tools work in this mode.

The second unpleasant point is that the presence of brushes and constant friction leads to the need for regular Maintenance. If the current collector is not cleaned, contamination with graphite (from brushes being worn out) can cause adjacent sections in the drum to become connected and the motor simply stops working.

Asynchronous

An asynchronous motor has a stator and a rotor, and can be single or three-phase. In this article we consider connecting single-phase motors, so we will only talk about them.

Asynchronous motors are characterized by a low noise level during operation, therefore they are installed in equipment whose operating noise is critical. These are air conditioners, split systems, refrigerators.

There are two types of single-phase asynchronous motors - bifilar (with a starting winding) and capacitor. The whole difference is that in bifilar single-phase motors the starting winding works only until the motor accelerates. Afterwards it is turned off by a special device - a centrifugal switch or a start-up relay (in refrigerators). This is necessary, since after overclocking it only reduces efficiency.

In capacitor single-phase motors, the capacitor winding runs all the time. Two windings - main and auxiliary - are shifted relative to each other by 90°. Thanks to this, you can change the direction of rotation. The capacitor on such engines is usually attached to the housing and is easy to identify by this feature.

You can more accurately determine the bifilar or capacitor motor in front of you by measuring the winding resistance. If the resistance of the auxiliary winding is twice as large (the difference can be even greater), most likely this is a bifilar motor and this auxiliary winding is a starting winding, which means that a switch or starting relay must be present in the circuit. In capacitor motors, both windings are constantly in operation and connecting a single-phase motor is possible through a regular button, toggle switch, or automatic machine.

Connection diagrams for single-phase asynchronous motors

With starting winding

To connect a motor with a starting winding, you will need a button in which one of the contacts opens after switching on. These opening contacts will need to be connected to the starting winding. In stores there is such a button - this is PNDS. Its middle contact closes for the holding time, and the two outer ones remain in a closed state.

Appearance of the PNVS button and the state of the contacts after the “start” button is released"

First, using measurements, we determine which winding is working and which is starting. Typically the output from the motor has three or four wires.

Consider the option with three wires. In this case, the two windings are already combined, that is, one of the wires is common. We take a tester and measure the resistance between all three pairs. The working one has the lowest resistance, the average value is the starting winding, and the highest is the common output (the resistance of two windings connected in series is measured).

If there are four pins, they ring in pairs. Find two pairs. The one with less resistance is the working one, the one with more resistance is the starting one. After this, we connect one wire from the starting and working windings, and bring out the common wire. A total of three wires remain (as in the first option):

one from the working winding is working;
from the starting winding;
general.

With all these

connecting a single-phase motor

We connect all three wires to the button. It also has three contacts. Be sure to place the starting wire on the middle contact(which is closed only during start-up), the other two are extremelyie (arbitrary). We connect a power cable (from 220 V) to the extreme input contacts of the PNVS, connect the middle contact with a jumper to the working one ( note! not with the general). That's the whole circuit for switching on a single-phase motor with a starting winding (bifilar) through a button.

Condenser

When connecting a single-phase capacitor motor, there are options: there are three connection diagrams and all with capacitors. Without them, the engine hums, but does not start (if you connect it according to the diagram described above).

The first circuit - with a capacitor in the power supply circuit of the starting winding - starts well, but during operation the power it produces is far from rated, but much lower. The connection circuit with a capacitor in the connection circuit of the working winding gives the opposite effect: not very good performance at start-up, but good performance. Accordingly, the first circuit is used in devices with heavy starting (for example), and with a working capacitor - if good performance characteristics are needed.

Circuit with two capacitors

There is a third option for connecting a single-phase motor (asynchronous) - install both capacitors. It turns out something between the options described above. This scheme is implemented most often. It is in the picture above in the middle or in the photo below in more detail. When organizing this circuit, you also need a PNVS type button, which will connect the capacitor only during the start time, until the motor “accelerates”. Then two windings will remain connected, with the auxiliary winding through a capacitor.

Connecting a single-phase motor: circuit with two capacitors - working and starting

When implementing other circuits - with one capacitor - you will need a regular button, machine or toggle switch. Everything connects there simply.

Selection of capacitors

There is a rather complex formula by which you can calculate the required capacity accurately, but it is quite possible to get by with recommendations that are derived from many experiments:

The working capacitor is taken at the rate of 70-80 uF per 1 kW of engine power;
starting - 2-3 times more.

The operating voltage of these capacitors should be 1.5 times higher than the network voltage, that is, for a 220 volt network we take capacitors with an operating voltage of 330 V and higher. To make starting easier, look for a special capacitor for the starting circuit. They have the words Start or Starting in their markings, but you can also use regular ones.

Changing the direction of motor movement

If, after connecting, the motor works, but the shaft does not rotate in the direction you want, you can change this direction. This is done by changing the windings of the auxiliary winding. When assembling the circuit, one of the wires was fed to the button, the second was connected to the wire from the working winding and the common one was brought out. This is where you need to switch the conductors.

As a 3-year-old boy, I bought myself for 113 rubles. Motorcycle MV-18. In my opinion, this is the most successful version of a bicycle moped. I drove it for 17 years and my son already broke it. 3 years ago I saw on the market a Chinese Hole Forester with an F50 (KD50) bicycle motor. I remembered my childhood and bought it for 11,300 rubles. I would like to give a comparative analysis of the D and KD motors. It makes sense to compare D8 and KD50: D8 is the last in the D series, KD50 and KD80 are structurally identical. Both models have a common ancestor D5. There is a version that the USSR transferred the D4 and D5 production lines to the PRC. What is the difference between D8 and KD50 from D5. More advanced power supply, ignition and exhaust systems. The D8 carburetor is more convenient to adjust. On my D6, I adjusted the mixture quality on the fly on almost every trip. The ignition system now has a light winding and an ignition coil. The new muffler gave a significant increase in power. In short, modernization proceeded by complicating the design. The Chinese took a different route. The carburetor has become simpler. Adjusting the quality of the mixture is achieved by setting the fuel level in the float chamber. The air filter mesh set has been replaced with foam rubber. The spool fuel supply system has been replaced by a piston one. The ignition on the CD has become electronic. Moreover, my Forester has a UOZ centrifugal regulator. Sometimes there is a light winding present. The CD clutch has become single-disc. Manipulating the muffler allows you to increase engine power. The Chinese abandoned the cast iron cylinder liner. In general, the D8 engine is more durable than the KD50. But more often it requires maintenance. CD is more powerful and simpler. Spare parts for both are quite available. The most common malfunction of my D6: The engine does not start - there is a spark, the spark plug is wet. As a kid, in such cases, I cut circles around the block, periodically changing the position of the air filter flap. My MV-18 lived for 17 years because I acted on the principle of “do no harm.” Until a diagnosis has been established, there is no need to tighten the screws. You always have to think, can you return everything to the way it was? The best is the enemy of the good. If your hands are still itching, then first buy the part that you want to modernize and experiment with it. Now some advice for beginners. A bicycle moped is a low-budget option. The following tips. If Grandpa's Dashka is lying around somewhere, try to revive it. You can find spare parts on the Internet. If you have the opportunity to buy a ready-made bicycle moped, take it. If you are going to install a velomotor on a bicycle, first buy a velomotor (KD50 is faster, KD80 is faster, you can find a new D8, but I don’t recommend it). Criteria for choosing a bike: I strongly recommend front shock absorbers (otherwise you will hit the 5th point and the spokes will fly). If it’s expensive, then don’t buy it with small wheels (for the same reason): where the big wheel rolls over an obstacle, the small one hits. Now regarding the operation. If you browse moped forums, you will find a lot of smart tuning tips. If a bicycle moped is your means of transportation, then ride until something breaks. The main criterion for engine tuning is the color of the spark plug electrodes (brick). The developers of the D series recommended a new type of spark plug for each model, from A10 on D4 to A23 on D8. So try it yourself. KD has something Chinese in it. A plug that is too hot results in hot ignition; a plug that is too cold causes oiling. Now about the ignition. Electronic ignition is more reliable and does not require maintenance. But if you have a contact ignition, then do not try to throw it away. The OZ can be changed on it as well. Parts are available for sale. The D5 had one magneto and cams. They suggest replacing the cams with a board and a bobbin. The ignition is faulty - what should I change? If you are comfortable with electronics, take the flag into your hands. If not, buy a CD ignition and, after tinkering a little, set it to D.