|
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese|
ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING Automatic shutdown of the pump. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Home, household, hobby The magazine "Radio" has repeatedly described various designs for the automatic control of a pumping pump, for example, devices that monitor the level of water either in its source, or in a receiving tank, or in both places. Sometimes it is more convenient to start the pump manually, and assign only the functions of monitoring the overflow of the tank to the machine. In the published article, the author proposes two simple variants of such an automaton. The circuit of the machine is quite simple if you use a float water level sensor (Fig. 1). When the receiving tank is not full, the SA1 sensor contacts are open. After pressing the SB1 button, the mains voltage is supplied to the pump motor M1 and through the capacitor C1 and the rectifier bridge VD1 to the winding of the electromagnetic relay K1. The relay is activated and with its contacts K1.1 blocks the contacts of the button SB1.
When the receiving tank is filled to a predetermined level, the contacts SA1 of the sensor close, the relay K1 releases, its contacts open and disconnect the motor M1 from the network. The device goes into the initial state. To restart the pump, press the SB1 button again. Capacitor C1 is ballast and serves to reduce the voltage on the relay winding to its operating value, resistor R1 limits the recharging current of the capacitor at the moment the SA1 sensor contacts are closed. The RPU-2 relay with a winding resistance of 4.5 kOhm and an operating voltage of 110 V is used in the machine. It has a special coil covering part of the magnetic circuit, which makes the relay insensitive to supply voltage ripples. When using another relay to ensure the operating voltage on its winding, you may have to connect a capacitor with a capacity of about 1 μF for a voltage of at least 1 V in parallel with the output diagonal of the VD160 bridge and select the capacitance of capacitor C1. The SB 1 button must be rated for the full current of the pump motor, and the capacitor C1 must have an operating voltage of at least 400 V (for example, K73-16 or K73-17). Bridge VD1 - any for a voltage of at least 300 V, you can use four separate diodes for the same voltage. However, the float sensor is not very convenient. Its contacts are connected to network wires, which requires increased safety measures during operation. On fig. 2 shows a diagram of an automaton with a proximity sensor, the electrodes of which are connected to inputs 1 and 2. The supply voltage is supplied to the device when the contacts of the SA1 switch are closed. If the receiving tank is not completely filled, the base current of the transistor VT1 is zero and it is closed. A voltage of 27 ... 30 V from the output of the rectifier through the R5C2 circuit is supplied to the winding of the relay K1, which is activated at the moment SA1 is turned on and turns on the pump motor with its contacts K1.1 and K1.2. As the capacitor C2 charges, the current through the relay winding K1 decreases, but the current flowing through the resistor R4 is enough to hold it. The HL1 red LED is on and indicates the machine is on.
When the tank is filled, a current appears between the sensor electrodes and the transistor VT1 opens. Its collector current lights up the green LED HL2, indicating the filling of the tank, and turns off relay K1. Contacts K 1.1 and K1.2 of the relay open and the pump motor stops. When water is consumed, the base current of the transistor VT1 will become equal to zero, it will close, the HL2 LED will turn off. The relay, however, will not operate because there is not enough current flowing through resistor R4. To restart the pump, switch SA1 off and on again. Capacitor C1 suppresses pickups on the wires going to the sensor electrodes, resistor R5 limits the recharging current of capacitor C2. current through the transistor VT1 at the moment it is turned on. The voltage divider R1R2 sets the voltage at the sensor electrodes and limits the base current of the transistor VT1. The device is assembled by surface mounting in the RF73Sh industrial photorelay housing. From it, a relay, a power transformer, a circuit board and a terminal block were used. Relay - MKU-48. passport RA4.501.088 with a winding resistance of 510 ohms and an operating voltage of 24 V. The transformer must provide a voltage of 22 ... 26 V on the secondary winding at a load current of at least 50 mA. Any transformer of the TN series with four secondary windings connected in series, as well as many CCI transformers with an appropriate connection of their secondary windings, for example, TPP216, will do. CCI218. CCI223 - CCI226. When making a transformer yourself, you can use the tips given in the Radio magazine for 1997, No. 7. p. 36, 37, Any resistors are suitable, oxide capacitors are also any, the operating voltage of C2 and C3 is at least 40 V. It is advisable to use the indicated glow color for LEDs. Bridge VD1 must be designed for a voltage of at least 50 V, it is permissible to use four separate diodes for the same voltage. Transistor VT1 of medium power of the n-p-n structure, for example, the KT503 series. KT602, KT603. KT608 with any letter indices, as well as high power - KT815 series. KT817. Switch SA1 is designed for the full current of the pump motor. The author used a conventional electrical wall switch, installing it outside the device case in a break in the phase wire of the network. The use of a relay with two pairs of closing contacts completely eliminates the appearance of mains voltage on the wires stretching through the garden plot when the pump is not working. If the relay has only one pair of contacts, they should be placed in a break in the phase wire of the network. It is also possible to replace the SA1 switch with a button picked up by the relay contacts (see Fig. 1), in this case, after filling the tank, the entire device is de-energized. In this version of the machine, the HL2 LED is not needed. The receiving tank is a 200 l polyethylene barrel. It is installed in the attic of the garden house. The electrodes are two pieces of galvanized steel pipe, introduced into the barrel from above through its threaded plugs. Through one pipe, reaching the bottom of the barrel, it is filled and water is taken into the house's plumbing. The other one (its length is about 80 mm and a polyethylene corrugated pipe is connected to it) serves to drain excess water when the barrel overflows due to a failure of the machine or a break in the wires leading to the sensor. Author: P.Aleshin, Moscow
Machine for thinning flowers in gardens
02.05.2024 Advanced Infrared Microscope
02.05.2024 Air trap for insects
01.05.2024
▪ The impact of fast food on sleep and memory of adolescents ▪ The new analogue of GPS will not need satellites ▪ Vulnerability of USB devices ▪ Electric shock against weeds ▪ Three years under the gaze of TV cameras
▪ site section Electrician's tool. Article selection ▪ article by Grace Hopper. Famous aphorisms ▪ How did the Punic Wars happen? Detailed answer ▪ article Voronets spiky. Legends, cultivation, methods of application ▪ article DC Amplifier. Encyclopedia of radio electronics and electrical engineering ▪ article Double balanced mixer SA612A. Encyclopedia of radio electronics and electrical engineering
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua |
See other articles Section 
Latest news of science and technology, new electronics:
All languages of this page