T.K. Hareendran is a freelance electronic circuit designer, technical writer, columnist, and consultant. He holds a diploma in electronics engineering from SK Polytechnic, Tamil Nadu, India, and a diploma in computer hardware & networking from CFET, Tamil Nadu. Email address: teksign@rediffmail.com
3 results found for T.K. Hareendran, displaying items 1 - 3
February 26, 2009[Ideas For Design] Create Your Own Fan Driver Circuit For An Active Heatsink
Even robotic systems occasionally need a cooling fan. When they do, the cooling circuit must be an intelligent one that makes minimal demands on power consumption and space. The circuit described here is such a cooling fan driver for an active heatsink assembly. The driver uses readily available and inexpensive components, and it runs on a 12-V dc supply (see the figure). The circuit uses an LM35...
September 11, 2008[Ideas For Design] Over-Temperature Alarm Circuit Uses Common, Inexpensive Components
A few simple components are all it takes to create an over-temperature alarm. The circuit in Figure 1 requires only an ordinary negative-temperature-coefficient (NTC) thermistor, two common ICs, and a handful of discrete components. The circuit uses a unipolar 12-V supply and consumes only a few milliamps in the idle state. This circuit is particularly suitable for monitoring the temperature of heatsink plates. ...
August 28, 2008[Ideas For Design] Use Inexpensive Components To Create An Infrared Close-Object Alert Circuit
Many robotic applications require a sensor to detect close or very close obstacles. Typically, reflective-type infrared sensors are used for this task. But the circuit in the figure shows an infrared close-object alert system built around two popular and less expensive integrated circuits: the LM555 timer and CD4060 CMOS, 14-stage, ripplecarrying binary counter/divider and oscillator. At the heart of the circuit lies a CNY70 reflective opto...
