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Showing posts with the label Fan

Fan Speed ​​Control for Temperature Circuit Diagram

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With this simple circuit that you will be able to control the speed of a DC fan according to the temperature measured by a temperature sensor. It is an ideal accessory for your projects that require cooling that are not constant.  This simple design allows precise speed control of motors, fans, and blowers, proportional to the temperature. An NTC thermistor (R1) is used as temperature sensor. A circuit optional was added to remotely monitor the operation of the fan and to allow some kind of indication of the approximate speed by increasing the brightness of an LED.  Fan Speed ​​Control for Temperature Circuit Diagram The R5 must be configured to allow the engine just starting to run at the desired temperature. Any 6K8 between the NTC thermistor 22K can operate provided that the R2 value is one tenth of the thermistor. R6, R7 and D1 are optional: R7 obligation is adjusted until the LED glow dimly when the engine is just running. Parts List R1 15K @ 20 ° C NTC Thermistor (See No...

On Demand WC Fan Using 555

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In most WCs with an extractor the fan is connected to the lighting circuit and is switched on and off either in sympathy with the light or with a short delay. Since toilets are sometimes used for washing the hands or just for a quick look in the mirror, it is not always necessary to change the air in the smallest room in the house. The following circuit automatically determines whether there really is any need to run the fan and reacts appropriately. No odour sensor is needed: we just employ a small contact that detects when and for how long the toilet seat lid is lifted. On-Demand WC Fan circuit Using 555 If the seat lid is left up for at least some presettable minimum time t1, the fan is set running for another presettable time t2. In the example shown the contact is made using a small magnet on the lid and a reed switch mounted on the cistern. The rest is straightforward: IC2, the familiar 555, forms a timer whose period can be adjusted up to approximately 10 to 12 minutes using P2....

Build Improvised Fan Grills

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Making your own grill for your fans would be a lot easier and cheaper. You could use all materials that can be found in your home. Your main component would be your old fan, removed its metal ring and you can now measure the desired length or size of grid that you will be needed. Cut the grid across so it will be easier to cut, then place it in the tower and use the same screw you removed in the fan. Now you can put the grid holding fan back in its place. Clean up and you can now use your very own fan grills that cost almost nothing but your patience.

Control Switch for Fan and Air Conditioner

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An electronic switch that can be used to switch on both the air-conditioner as well as fan of your room, one by one. The circuit consists of power supply and control sections. The power supply section is built around transformer X1, bridge rectifier BR1 and filter capacitor C1. The 50Hz, 230V AC mains is stepped down by transformer X1 to deliver a secondary output of 9V, 300 mA. The transformer output is rectified by the bridge rectifier and filtered by capacitor C1. Control Switch for Fan and Air-Conditioner  Circuit Diagram When the mains is switched on for the first time, pin 3 of IC CD4017 (IC1) goes high and relay RL1 energies to switch on the fan. When mains is briefly switched off using S1 and then switched on, the power to IC1 is maintained by the charge on capacitor C1. At the same time, there is a trigger pulse on the clock input (pin 14) of IC1, which advances the decade counter and relay RL2 energies to switch -on the air-conditioner. Both the air-conditioner and the f...

Kitchen Exhaustion Fan Controller

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Exhaustion fan is a very important element in kitchens. Here may be a easy circuit to manage kitchen fans by monitoring the ambient temperature. it's engineered round the renowned precision integrated temperature sensor chip LM35 (IC1). remainder of the circuit may be a non-traditional electromagnetic relay driver wired round the fashionable LED driver LM3914 (IC2). User will switch 3 presetted temperature levels employing a jumper/slide switch (JP1), that determines the warmth level to activate the relay and hence the electrical exhaustion fan wired through the relay contacts. It works off 12V DC power offer. Kitchen Exhaustion Fan Controller  Circuit Schematic Only one adjustment is needed during this kitchen Exhaustion fan controller circuit. when construction, set jumper purpose in its 1st position, ie base terminal of T1 is connected to pin thirteen of IC2 and alter the preset P1 fastidiously in order that relay RL1 is energised when ambient temperature level reaches close to ...

Efficient Fan Speed Controller Circuit Diagram

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A partial solution to quietening noisy PCs can be to reduce the speed of internal cooling fans. Low-cost fan speed controllers are available, but they often employ inefficient, heat-generating linear regulators and contain no temperature feedback mechanism. This idea makes use of a readily available, cheap in-car mobile phone charger. The majority of these use common circuitry and require only minor modifications to operate as efficient fan speed controllers complete with temperature feedback. Most in-car chargers are based on the well-known MC34063 DC-DC switchmode IC. When used for charging mobile phones, the open-circuit output voltage is typically set to between 7V and 9V. This is achieved with a simple voltage divider across the output, the centre point of which connects to the feedback input (pin 5) of the MC34063. To make the output voltage var-iable with air temperature, first replace the upper resistor of the divider with a 4.7kΩ resistor in series with a 4.7kΩ trimpot. The lo...