PWM Motor Controller

PWM Motor Controller With Forward And Reverse is circuit controllers for DC motors controlled by PWM technique . The series PWM Motor Controller With Forward And Reverse It can control the DC motor rotation direction. Speed ​​control by PWM technique through MOSFETs Q1 IRF150. Then to play with the directional control relay which is controlled by Q10 using control signals in the form of logic 0 and 1. The series PWM Motor Controller With Forward And Reverse It requires 12 VDC supply voltage.

Circuit PWM Motor Controller With Forward And Reverse the above can be used to control large DC motor with maximum current consumption 10A.

Read more

Cheap Pump Controller

This simple but effective circuit can be used to control water level in a container. The prototype is used to pump water out of a bucket that collects condensation from a home air-conditioning system. The design is based around a 555 timer (IC1). Although the timer in configured as a mono-stable, it lacks the usual timing capacitor from pin 6 to ground. Instead, a metal probe inserted in the water provides a current path to a second, grounded probe. When the water level in the container reaches a third ("high") probe, the trigger input (pin 3) is pulled low, switching the 555 output high and energizing the relay via transistor Q1.

 

Cheap Pump Controller Circuit Diagram

Once the water level drops below the "low" probe, the threshold input (pin 6) swings high, switching the output (pin 3) low and the relay and pump off. The two 100kΩ pull-up resistors can be replaced with larger values if more sensitivity is required (eg, if the 555 doesn’t trigger). A switch (S1) can be included to bypass the relay for manual emptying. The "low" probe should be positioned so that the pump doesn’t run dry.

The high level probe is placed at the level that you want the pump to start. Since the water is held at ground potential, you must use stainless steel or copper wire to slow corrosion. With water fountain pumps available for less than $10, this circuit offers a cheap alternative for those who have an air-conditioner on an internal wall and don’t want to be continually emptying the bucket on humid days.

Read more

Simple Automatic Overhead Water Level Controller Circuit

 In most of the cities and towns in our country the corporation or municipal water supply is restricted to a few hours in the morning and evening. So nowadays most of the urban houses are equipped with overhead water tanks to ensure 24-hour water supply.

Water to these tanks is pumped from a low—level tank which gets water fr0m the corporation supply lines. Level of water in these tanks is generally maintained by mechanical float valves. Maintenance of the minimum water level in the overhead tanks is not so easy. Usually 0nly after the water is comple  tely finished will we come to know about that. The unit described here will switch on and switch off the pump so as to maintain the level within the desired limits.

Whenever the level reaches the lower set limit the pump is switched on. and it will be switched off when the level reaches the upper set limit. The unit can be powered from the domestic AC mains and consumes very little power. A special probe is however required to sense the level of water. The probe  Fig. 1 shows the probe fitted inside a water tank. The probe can be made from a PVC tube with length equal to the depth  of the tank. Three brass or copper rings are fitted to the tube with Araldite. The positioning of the upper and middle rings determines the upper and lower limits. Wire connections to the rings can be made from inside before fixing them. The bottom end of the tube must be sealed with a plastic cap and Araldite. A 3-core cable must be used for connecting the probe to the unit. This ensures complete protection of the leads from moisture and rain

The circuit & construction

 The circuit (Fig. 2) uses four transistors, five diodes, seven resistors, three capacitors, one relay and transformert A When the tank is full the probe is completely immersed in water and all the rings touch the water. Thus points A and B and points A and C will be connected through water as  The circuit & construction T The circuit (Fig. 2) uses four transistors, five diodes, seven resistors, three capacitors, one relay and transformert A When the tank is full the probe is completely immersed in water and all the rings touch the water. Thus points A and B and points A and C will be connected through water as  treated water is a conductor of electricity. (Only pure water is an insulator.) Hence, transistors Tl and T2 get base bias and will be saturated. Their collector voltages will be now around 0.3 V. So transistors T3 and T4 will be cut off and the relay will be de-energised, cutting off the power to the pump motor. When the water level is in-between rings B and C, transistor T2 is cut off and Tl is saturated. The collector voltage of T2 is now very near to the supply voltage and transistor T4 gets saturated. Since T3, T4 and the relay are in series, in order to energise the relay both the transistors must be saturated. When the water level goes just below the B ring, the base bias to transistor Tl is cut off, thereby switching it off. Now its collector voltage swings to supply voltage and T3 is  saturated. Sinc T4 is already saturated, the relay will be energised switching on power to the motor. The base of T1 also gets grounded through th N/O relay contacts. This ensures that during pumping, when the water level again reaches the B ring, transistor Tl is not saturated and T3 is switched off. As the motor goes on pumping, the tank is filled and the water level reaches the C ring. Transistor T2 is now saturated and T4 is cut off, thereby de-energising the relay. The power to the motor is now cut off and the grounding of Tl base is removed. This cycle will be repeated again as the water level goes below the B ring. Diode D3 suppresses the surge voltages developed across the relay coil. D1 and D2 increase the threshold of switching of T3 and T4. Capacitors Cl and C2 bypass any transients appearing at the base of Tl and T2 and increase the noise immunity of the system.   The power supply is an ordinary full-wave rectifier. Neon  saturated. Sinc T4 is already saturated, the relay will be energised switching on power to the motor. The base of Tl also gets grounded through th N/O relay contacts.

This ensures that during pumping, when the water level again reaches the B ring, transistor Tl is not saturated and T3 is switched off. As the motor goes on pumping, the tank is filled and the water level reaches the C ring. Transistor T2 is now saturated and T4 is cut off, thereby de-energising the relay. The power to the motor is now cut off and the grounding of Tl base is removed. This cycle will be repeated again as the water level goes below the B ring. Diode D3 suppresses the surge voltages developed across the relay coil. Dl and D2 increase the threshold of switching of T3 and T4. Capacitors Cl and C2 bypass any transients appearing at the base of Tl and T2 and increase the noise immunity of the system.   The power supply is an ordinary full—wave rectifier. Neon  lamp L1 indicates the ‘power on’ condition. lt must be noted that the current rating of the relay contacts must be at least seven times greater than the rated current of the motor.  The PCB layout of the circuit is given in Fig. 3. The relay and the transformer can be wired externally. The whole unit can be mounted inside a suitable box. Wire connections to the unit can be made through terminal stations.

Adjustments

The circuit must be thoroughly checked before switching on. Set the trimpots to their maximum resistance position. Insert a piece of paper between the relay contacts connected to the base of `l`l. lmmerse the probe in water such that all the three rings are under water. Now adjust the trimpots such that the relay just energises. The unit may be mounted on the wall near the main switch for the motor.

Read more

Outdoor Lighting Controller

When you step out of your brightly-lit house  into the darkness, it takes a while for your  vision to adjust. A solution to this problem  is this outdoor light with automatic switch-off. As a bonus, it will also make it a little bit  easier to find the keyhole when returning  late at night. Often no mains neutral connection is avail-able at the point where the switch-off timer  is to be installed, which makes many circuit  arrangements impractical. However, the circuit here is designed to work in this situation. The design eschews bulky components such as transformers and the whole unit can  be built into a flush-mounted fitting. The circuit also features low quiescent current consumption.

Outdoor Lighting Controller Circuit Diagram :


The circuit is star ted by closing switch (or  pushbutton) S1. The lamp then immediately receives power via the bridge rectifier. The drop across diodes D5 to D10 is 4.2 V, which provides the power supply for the delay circuit itself, built around the CD4060 binary  counter.

When the switch is opened the lighting sup-ply current continues to flow through Tri1. The NPN optocoupler in the triac drive circuit detects when the triac is active, with antiparallel LED D1 keeping the drive sym-metrical. The NPN phototransistor inside the  coupler creates a reset pulse via T1, driving  pin 12 of the counter. This means that the  full time period will run even if the circuit is retriggered. The CD4060 counts at the AC grid frequency.  Pin 3 goes high after 213clocks, which corresponds to about 2.5 minutes. If this is not long  enough, a further CD4060 counter can be cascaded. T2 then turns on and shorts the internal LED of opto-triac IC2; this causes Tri1 to  be deprived of its trigger current and the light  goes out. The circuit remains without power until next triggered.

The circuit is only suitable for use with resistive loads. With the components shown (in particular in the bridge rectifier and D5 to  D10) the maximum total power of the connected bulb(s) is 200 watts. As is well known, the filament of the bulb is most likely to fail at the moment power is applied. There is little risk to Tri1 at this point as it is bridged by  the switch. The most likely consequence of overload is that one of diodes D1 to D6 will  fail. In the prototype no fuse was used, as it would not in any case have been easy to change. However, that is not necessarily recommended practice!

Circuits at AC line potential should only be constructed by suitably experienced persons and all relevant safety precautions and  applicable regulations must be observed during construction and installation.

 

 

 

 

Author : Harald Schad - Copyright : Elektor

Read more

Simple Automatic Water Pump Controller Circuit Diagram

Simple Automatic Water Pump Controller Circuit Diagram is a series of functions to control the Automatic Water Pump Controller Circuit in a reservoir or water storage. As the water level sensor made with a metal plate mounted on the reservoir or water tank, with a sensor in the short to create the top level and a detection sensor for detecting long again made the lower level and ground lines connected to the bottom of reservoirs or reservoir. 

The series of automatic water pump controller is designed with 2 inputs NOR by 4 pieces and relay that is activated by the transistor. Automatic water pump circuit requires +12 VDC voltage source and can be used to control the water pump is connected to AC power . Here is the complete series of pictures.

Automatic Water Pump Controller Circuit Diagram

working principle series of automatic water pump controller above is. At the time the water level is below both sensors, the output IC1C (pin 10) will be LOW, Kemudin when the water began to touch the lower level sensor, the output IC1C (pin10) remains LOW until the water touches the sensor level above, then the output IC1C (pin 10) going HIGH and active relay through Q1 and turn on the water pump to meguras reservoir. 

At the muli down and water level sensors for water untouched MKA IC1C output (pin 10) remains HIGH until the new water untouched semuasensor IC1C output (pin 10) LOW and water pump died. The series of automatic water pump controller is equipped with SW1 which serves to reverse the logic of drains (the output of IC1C) and the concept of water supplied (output dri IC1D). 

When SW1 is connected to IC1D the water pump will turn on when the water does not touch all the sensors and will die when all the sensors tesentuh water. Automatic water pump controller can be used to fill or drain the water according to which mode is selected via SW1.

List Component Automatic Water Pump Controller

R1 = 15K

R2 = 15K

R3 = 10K

R4 = 1K

D1 = LED

D2 = 1N4148

Q1 = BC337

IC1 = 4001

SW = SPDT Switches

Relay RL1 = 12V

Read more