Showing posts from July, 2014

Build Your First Robot - Transistors and Their Applications

As we know, a transistor generally has 3 pins - emitter, base and collector. The base is where the input signal is fed. The transistor acts as a switch and on receiving the input signal, it allows the current to flow from the collector to the emitter. As I have mentioned earlier, transistors work in a very narrow range of power supply, hence resistors must always be used with them to protect them from getting burnt. Now let's build our first circuit. This circuit will switch on an led when you touch the two ends of a wire.

In this circuit we will be using a BC547 transistor which is n-p-n. The longer leg of the led must be connected to the positive terminal of the battery and the shorter side must be connected to the collector of the transistor. Connect a wire to the positive side of the battery and another to the base of the transistor. A resistor of 150 ohms is connected in series with the emitter of the negative rail of the breadboard. Your first transistor circuit is done!

We w…

Build Your First Robot - Transistors (Little Deeper)

I was actually going to write a post featuring the applications of transistors. I even titled the post "Build Your First Robot - Transistors and their Applications", but then I thought , I must share a little bit more unorganized information about transistors. So, here it is!

As I have mentioned in my very first post, robotics is an interplay of mechanics, electronics and computer science. As we living organisms have sense organs to sense our environment, robots have sensors. Often this sensors are designed to work with a small power supply. Due to this, the output of these sensors are not strong enough to directly control the robot. Sensors' outputs often require amplification, and in theory we can use a common music amplifier with some modification for this purpose but as amplifiers draw a lot of current, in robotics transistors are used. Transistors are used as brains in many homemade robots and even the robots that have computers as their brains indirectly rely on t…

Build Your First Robot - Transistors

Transistors are one of the most interesting components in electronics. They form the heart of nearly everything. Everyone, well versed in technology or not, would have heard about this particular component. Those who haven't heard about it, no problem! We are today going to know more about this fascinating component. So, let's dive in!

A transistor is a semiconductor that is used to amplify an input. A transistor can take a small input signal and control a much larger one. There are various types of transistors. MOSFETS, BJT to name a few. The transistor that we are mainly concerned about for the purpose of building our first robot is a BJT (Bipolar Junction Transistor). There are mainly two types of BJT: n-p-n and p-n-p. BJT transistors have three connections: emitter, base and collector. The base is where the input signal is fed. In an n-p-n transistor the base has to be "more" positive than the emitter for the current to flow from the collector to emitter.Here, t…