The easiest way to regulate the speed of an electric motor, is to decrease / increase the supplied voltage. This can be done by putting an adjustable serial resistor in series with the motor. https://web.archive.org/web/20081222213911/http://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-2757683140936137&dt=1230067431898&lmt=1612436424&output=html&slotname=6542966663&correlator=1230067431898&url=https%3A%2F%2Fmayothi.com%2Fspeedcontrol2.html&eid=6083027&ea=0&frm=0&ga_vid=1883978985.1230067435&ga_sid=1230067435&ga_hid=726046104&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=11&u_nplug=3&u_nmime=4&dtd=M This is exactly how my first ‘Scalectric’ speed control worked. It had a high-resistance wire wrapped around a core and …

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We will show you how to build a speed control for only a fraction of the cost of those available commercially. This speed control uses a low-cost Pic12F675 micro controller and a few other basic components (resistors, capacitors, transistors, diodes and a regulator.) Below is a photo of the speed control connected to the motor …

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Diodes have the following properties: They only allow current to flow in one direction They have a specific voltage drop, which can be taken as a constant for most circuits https://web.archive.org/web/20090224113643/http://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-2757683140936137&dt=1235387152210&lmt=1612436233&output=html&slotname=6542966663&correlator=1235387152210&url=https%3A%2F%2Fmayothi.com%2Fdiodes.html&frm=0&ga_vid=861307647.1235387153&ga_sid=1235387153&ga_hid=918268353&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=8&u_nplug=3&u_nmime=4&dtd=M&w=728&h=90&xpc=uGwQh3BKCc&p=https%3A//web.archive.org A diode is represented with the following symbol: The diode above will pass current flowing from left to right, but block current trying to …

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I like the simplicity of my VW Polo’s standard radio unit, but I really need a bluetooth handsfree kit and iPod connectivity. I first tried an after-market kit that added the needed functionality to the factory radio, but after returning it for the third time (each time waiting more than a month for the replacement …

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A basic circuit Here is an example of using Ohm’s Law for a basic circuit (see the electronics introduction if you’re not familiar with Ohm’s law.) We have a resistor of 4k7 (4700 Ohm) connected to a 5V supply, what is the current flowing through it? https://web.archive.org/web/20090224113643/http://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-2757683140936137&dt=1235427218282&lmt=1612436182&output=html&slotname=6542966663&correlator=1235427218282&url=https%3A%2F%2Fmayothi.com%2Fresistors.html&frm=0&ga_vid=2137999440.1235427220&ga_sid=1235427220&ga_hid=1237380667&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=7&u_nplug=3&u_nmime=4&dtd=M&w=728&h=90&xpc=BvwG0wKY6e&p=https%3A//web.archive.org Answer I = V/R = 5V/4k7 = 1.06mA …

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Ohm’s Law Probably the most important law in electronics is Ohm’s Law. Ohms Law states that the voltage across a resistor equals the resistance of the resistor times the current flowing through it (V=R*I). Thus if you have a resistance of 1000 ohms and a current of 10 milliamps flowing through it, the voltage over …

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