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Fans and coolers automatic speed controller schematic showin

2015-03-01 07:04  
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This article is the fans and coolers automatic speed controller schematic presentation. By convention, in order to better grasp the principles you are, we recommend you to combine text read schematics. As you know, over time, one has to get up again and again the speed of the fan or cooler. The apparatus described here the fan running at full speed at a predetermined time. Speed ??is reduced to a period of time in the future slowly. After a period of about 8 hours, the fan / cooler for switching figs. 1 shows a circuit diagram of the system. IC1 (555), is used as an astable  multivibrator  generates a clock pulse. Decade of pulses into compasses / counter and by the IC3 IC2. These ICs as divided by 10 divided by 9 counters, respectively. Value of the capacitors and resistors R1 and R2 C1 so adjusted, the final output of IC3 to rise after about 8 hours. The first two output IC3 (Q0 and Q1) connected (or) through diodes D1 and D2 to the base of the transistor T1. Initially output Q0 is high, so the relay RL1 is full of vitality. It still energetic when Q1 becomes high. The method of this gadget is connected to the fan / cooler is given in figs 3 and 4. If you are a first reading on this principle, we recommend that you carefully read several times in order to better fully grasp this simple but effective circuit.



It can be seen that initially the fan shall get AC supply directly, and so it shall run at top speed. When output Q2 becomes high and Q1 becomes low, relay RL1 is turned ‘off’ and relay RL2 is switched ‘on’. The fan gets AC through a resistance and its speed drops to medium. This continues until output Q4 is high. When Q4 goes low and Q5 goes high, relay RL2 is switched ‘off’ and relay RL3 is activated. The fan now runs at low speed.Throughout the process, pin 11 of the IC is low, so T4 is cut off, thus keeping T5 in saturation and RL4 ‘on’. At the end of the cycle, when pin 11 (Q9) becomes high, T4 gets saturated and T5 is cut off. RL4 is switched ‘off’, thus switching ‘off’ the fan/cooler.Using the circuit described above, the fan shall run at high speed for a comparatively lesser time when either of Q0 or Q1 output is high. At medium speed, it will run for a moderate time period when any of three outputs Q2 through Q4 is high, while at low speed, it will run for a much longer time period when any of the four outputs Q5 through Q8 is high.If one wishes, one can make the fan run at the three speeds for an equal amount of time by connecting three decimal decoded outputs of IC3 to each of the transistors T1 to T3. One can also get more than three speeds by using an additional relay, transistor, and associated components, and connecting one or more outputs of IC3 to it.In the motors used in certain coolers there are separate windings for separate speeds. Such coolers do not use a rheostat type speed regulator. The method of connection of this device to such coolers is given in Fig. 4.The resistors in Figs 2 and 3 are the tapped resistors, similar to those used in manually controlled fan-speed regulators. Alternatively, wire-wound resistors of suitable wattage and resistance can be used.

Automatic Speed Controller for fans & Coolers

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