My Circuit

Here is the circuit of clap-operated remote control fans is used to control not only switching properties but also control speed of fan. The main advantage of clap operated remote control for fan is, it can control up to ten-step speeds of fan where normally a fan has three to five step speeds. Circuit description clap operated remote control for fan This entire circuit clap operated remote control for fan is divided into four major section i.e. sound-operated trigger pulse generator, clock pulse generator, clock pulse counter and load operator. Sound-operated trigger pulse : – The heart of this section is transistor T 1 BC148, configured as class-C amplifier mode. The MIC 1 is used to change voice signal into its corresponding electrical signal and is given to base of transistor T 1 in order to amplify and increase its intensity. Clock pulse generator :- This section is build around timer IC NE555 and configured as monostable multivibrator. The trigger pulse generated by transistor...

Small cooling fans are used in some equipment for cooling semiconductor devices. The circuit given here is of a simple automatic speed controller for a 12V, 0.6W (or 1.2W) cooling fan that increases the fan’s speed when temperature rises, and vice versa. Circuit and working Fig. 1 shows circuit diagram of the speed controller for a small cooling fan. Resistor R1 limits the initial current for the motor and lowers the speed of rotation, if needed. The temperature control is done with one or more NTC (negative temperature coefficient) thermistors connected in series with the electrical motor. The number of thermistors depends on their power dissipation. Usually you cannot find low-cost NTCs with enough power dissipation. Therefore four of them in parallel are used here. This way power dissipation and self-heating of the NTCs are reduced. It is better to use NTCs with tolerance of ±2%. The NTCLE100E3 are available with nominal values of 3.3-ohm to 470-kilo-ohm and have maximum power dissi...