Total solder points: 129 Difficulty level: beginner 1 2 3 4 5 advanced LIQUID LEVEL CONTROLLER K2639 ashing aking w re. So le , p ta n cu ff the to turn o tion is better tha nal n e tt o g r n e ctio Fo , ... Prev r. This multifun plications.
Introduction & Specifications Did you forget to turn off the tap? Is the washing machine leaking? Will the aquarium level fall too low? Has the rain water tank overflowed? Do you have water in the cellar? Just a minor mishap, or a disaster! You can avoid all this by installing the liquid level controller in the right way and in the right place. Level indicator : three LED's are used to indicate “LOW LEVEL”, “MEDIUM LEVEL” and “HIGH LEVEL”.
Assembly hints 1. Assembly (Skipping this can lead to troubles ! ) Ok, so we have your attention. These hints will help you to make this project successful. Read them carefully. 1.1 Make sure you have the right tools: A good quality soldering iron (25-40W) with a small tip. Wipe it often on a wet sponge or cloth, to keep it clean; then apply solder to the tip, to give it a wet look. This is called ‘thinning’ and will protect the tip, and enables you to make good connections.
Assembly hints 1.3 Soldering Hints : 1- Mount the component against the PCB surface and carefully solder the leads 2- Make sure the solder joints are cone-shaped and shiny 3- Trim excess leads as close as possible to the solder joint REMOVE THEM FROM THE TAPE ONE AT A TIME ! AXIAL COMPONENTS ARE TAPED IN THE CORRECT MOUNTING SEQUENCE ! You will find the colour code for the resistances and the LEDs on our website: http://www.velleman.be/common/service.
Construction 1. Jumpers J : 2x 2. Diodes. Check the polarity! D1 D2 D3 D4 D5 D6 : : : : : : 1N4148 1N4148 1N4148 1N4148 1N4148 1N4007 CATHODE 3. Resistors D...
Construction 8. Capacitor 10. Electrolytic capacitor. Watch the polarity ! C9 : 10µF / 25V 13. Relay C... RY... C11 : 22nF RY1 : VR15M121C 12V / 15A 9. PCB pins 11. Voltage regulator Fit four terminal pins between marks S1 and S2. You may also use screw connectors. VR1 : UA7812 Fit 6 terminal pins for the relay output (NO, C , NS) and the power supply (AC IN). You may also use screw connectors. 12. Electrolytic capacitor.
Testing 15. Testing Inspect the completed board thoroughly before connecting a power supply. When applying a DC voltage (16 to 18V/100 mA) : The positive input should go to the pin nearest “AC IN”, the negative input to the second pin (Fig 1.0). NO C + NC VR1 ACin ACin Fig 1.0 ADAPTER (16-18VDC/100mA) NO C NC Fig 2.0 VR1 ACin ACin For connecting a transformer (12 to 14V/min 300 mA): The connection sequence isn’t important (Fig 2.0). 2x 7.
Testing With power on, LD3 (LOW LEVEL) should illuminate, showing that everything works. LD1 LD2 LD4 LD3 Put a link across low-level sensor S2, and LD2 should illuminate. S2 Fig 3.0 LD1 LD2 LD4 LD3 Add another link across high-level sensor S1, and LD1 and LD4 should S1 both illuminate. S1 S2 Fig 3.1 LD1 LD2 LD4 LD3 Remove the link across input sensor S1, now LD2 should illuminate together with LD4 (relay on). S1 S2 Fig 3.2 LD1 LD2 8 LD4 Fig 3.
Applications 16. Applications For application as controller/indicator and alarm, 1 or 2 sensors must be connected. A sensor consists of 2 separated electric conductors : 2 metal strips on a PCB or a jack plug etc. There are 2 sensors on the sensor PCB : S1 (HIGH LEVEL) and S2 (LOW LEVEL). Cut a piece of your sensor PCB when the difference in height between S1 and S2 is too high for your application (Fig 4.0). Fig 4.
Applications A dry sensor behaves like an electric isolator. When the sensor is wet the resistance drops to some Kilo-Ohms maximum. The electrical resistance of a sensor depends on the conductivity of the liquid, spacing between the electrodes, and the wet areas of the electrodes. The specific conductivity of some liquids is so high that this controller can’t detect them. Sometimes the problem may be solved by increasing the surface of the electrodes.
Applications Working : With both sensors dry, LD3 illuminates (LOW LEVEL), fig 6.0 When sensor S2 is wet, LD2 illuminates (MEDIUM LEVEL), fig 6.1 When the liquid level rises and S1 also becomes wet, LD1 (HIGH LEVEL) and LD4 (relay “on”) illuminate, fig 6.2 If the level then falls and only sensor S2 remains wet, LD2 and LD4 illuminate, fig 6.3 If the level keeps falling and sensor S2 also becomes dry, only LD3 illuminates, and the relay is switched off, fig 6.0 To Main PCB To Main PCB LD3 LD2 Fig 6.
Applications NOTE : the relay is switched on when the level reaches S1 (HIGH LEVEL) and is then switched off when the level falls under S2 (LOW LEVEL) ATTENTION : The relay contacts are rated at 3 Amps max. ALARM Link the pins of sensor S1 to the pins of sensor S2 as follows : 1) link the pin near C5 to the pin near C6 2) link the pin near C4 to the pin near C7 Connect pins adjacent to C4 and C5 to a sensor. When dry, LD3 illuminates (Fig 7.0).
Applications ALARM WITH HOLD MEMORY I. Alarm when the sensor detects liquid : Mount liquid sensor S1 and connect a NC pushbutton with the connection pins of sensor S2. As soon as the sensor detects liquid, the relay receives power (LED LD4 starts burning) and remains powered, even when the sensor returns to a dry state. The alarm device is activated through the NO relay. The alarm cannot be switched of before the sensor has stopped detecting liquid.
Schematic diagram 17. Schematic diagram.
PCB 18.
VELLEMAN NV Legen Heirweg 33, B-9890 GAVERE Belgium (Europe) Modifications and typographical errors reserved © Velleman nv. H2639IP’1 - 2014 (rev.