Background There seems to be a lot of confusion surrounding the practise of switching off your geyser on a daily basis. Some people claim huge savings, while others warn that you might even consume more electricity, but the general consensus seems to be that you won’t really notice a saving. Despite the fact that saving …
Can you save electricity by switching your geyser off on a daily basis? Read More »
Transistor Terminology A transistor has three legs: a collector, an emitter and a base. Below is the symbols for an NPN and a PNP transistor. NPN transistor https://web.archive.org/web/20081029225342/http://pagead2.googlesyndication.com/pagead/ads?client=ca-pub-2757683140936137&dt=1225340342608&lmt=1612436893&output=html&slotname=6542966663&correlator=1225340342602&url=https%3A%2F%2Fmayothi.com%2Ftransistors.html&ea=0&frm=0&ga_vid=852767767.1225340343&ga_sid=1225340343&ga_hid=1881404826&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=17&u_nplug=3&u_nmime=4 PNP transistor Transistors as switches The easiest way to understand transistors is to think of them as switches. You can switch a big current (between the collector …
The schematics can be downloaded here. The 5V supply The 5V supply is only used if you want to power the motor and receiver/servo’s from the main battery pack. Skip this part if you want to use a separate battery pack for the motor and the servo’s. The battery pack is connected to an LM2940 5v …
I bought a Pioneer radio and wanted to bypass the brake detection circuit to watch DVD’s. The unit has a wire that needs to detect nothing on the wire when you turn the vehicle on, and then a connection to Ground (handbrake on) before enabling the DVD player. On the internet you can find a circuit where they …
Servo’s also work with Pulse width modulation. The length of the pulse is between 1ms (fully left) and 2ms (fully right.) Of course I might be wrong about the left and right, but it boils downto this: 1ms is maximum one direction and 2ms is maximum the other direction. https://web.archive.org/web/20081029225342/http://pagead2.googlesyndication.com/pagead/ads?client=ca-pub-2757683140936137&dt=1225333568626&lmt=1612436589&output=html&slotname=6542966663&correlator=1225333568625&url=https%3A%2F%2Fmayothi.com%2Fspeedcontrol4.html&ea=0&frm=0&ga_vid=2101683390.1225333569&ga_sid=1225333569&ga_hid=58216249&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=13&u_nplug=3&u_nmime=4 You will notice two differences …
You can control the amount of power the motor gets by using a switch and turning it on and off very quickly. https://web.archive.org/web/20081204151759/http://googleads.g.doubleclick.net/pagead/ads?client=ca-pub-2757683140936137&dt=1228386005879&lmt=1612436521&output=html&slotname=6542966663&correlator=1228386005879&url=https%3A%2F%2Fmayothi.com%2Fspeedcontrol3.html&ea=0&frm=0&ga_vid=463190824.1228386007&ga_sid=1228386007&ga_hid=1035464916&flash=0&u_h=864&u_w=1536&u_ah=834&u_aw=1536&u_cd=24&u_his=12&u_nplug=3&u_nmime=4&dtd=M If you want the motor to turn slowly, the switch is longer open than it is closed: If you want the motor to turn fast, the switch is longer closed than open: …
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 …
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 …
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 …
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 …
