SparkFun Electronics - News Few LM317 Voltage regulator circuits that has a lot of applications Few LM317 voltage regulator circuits Some circuits based on LM317 voltage regulator Few useful circuits using the voltage regulator IC LM317 is shown here. LM317 is a three terminal voltage regulator IC from National Semiconductors. Typical positive voltage regulator circuit using LM317. LM317 Adjustable Regulator A classic voltage regulator circuit using LM317 is shown above. Adjustable regulator with digitally selected output. LM317 voltage regulator with digitally selected output A very simple adjustable regulator circuit with digitally selected output is shown above. 5A constant current constant voltage regulator. 5A constant current constant voltage regulator The circuit shown above is of a 5A constant current / constant voltage regulator using LM317. Power follower circuit using LM317. A voltage follower circuit is a circuit which produces considerable current gain while the voltage gain is maintained unity (or close to it). Power follower circuit Notes. Custom Search
Battery Tester Project Battery Tester Project Using LM3914 IC This objective of this project is to design and build a battery tester that is able to test various types of dry cell and rechargeable battery with a voltage of less than 2V. Configured as a bar graph battery level indicator, the LM3914 IC from National Semiconductor senses the voltage levels of the battery under test and drives the 10 LEDs to ON or OFF based on the voltage that is detected. The current driving the LEDs is regulated by using the external resistor R1 and hence limiting resistors are not required. The schematic shows the simple connections where the reference voltage at pin 8 of U1 can be adjusted by adjusting the variable resistor VR1. Test the circuit by using a breadboard before soldering the parts onto the PCB. If testing of rechargeable battery such as NiCd or NiMH is required, set the reference voltage to a lower value such as 1.5V as the typical voltage of a rechargeable battery is approximately 1.2V.
cd-rom tricks Quote: Here you go: Not just straight so easy. It can increase the max torque achieved by the motor. The torqque will be square to to the stator lenght. Torque easy tranclates to magnetic force between stator and rotor. In example in twice longer stator you can get twice more MF at the same saturation level but at the same time you can use longer magnets in the twice longer rotor. So how to bring it back to the original Kv (and original rpm)? Isn't it slick? RysiuM
Sci.Electronics FAQ: Repair: Pinouts FAQ Contents: 7.3) Misc / Power Power Connector Male Speaker Connector Turbo Indicator Connector pin assignment pin assignment pin assignment 1 +12V 1 -Speaker 1 +5V 2 +12V return 2 [key] 2 -High Speed 3 +5V return 3 GND 3 +5V 4 +5V 4 +Speaker +5V AT LED Power and Key Lock AT Backup Battery pin assignment pin assignment 1 LED power 1 Batt+ 2 GND 2 [key] 3 GND 3 GND 4 Key Switch 4 GND 5 GND Motherboard Power Connectors pin P8 assignment pin P9 assignment 1 Power Good 1 GND 2 +5v (or N.C.) 2 GND 3 +12v 3 -5v 4 -12v 4 +5v 5 GND 5 +5v 6 GND 6 +5v MIDI 5pin DIN MIDI In MIDI Out pin assignment pin assignment 1 N/C 1 N/C 2 N/C 2 GND 3 N/C 3 N/C 4 Current Src 4 Current Sink 5 Current Sink 5 Current Src 7.5) Floppy 7.6) Game Port Game Port DB15-Female pin assignment pin assignment 1 +5V DC 2 Button 4 (A_PB1) 3 Position 0(A_X) 4 GND 5 GND 6 Position 1 (A_Y) 7 Button 5(A_PB2) 8 +5V DC 9 +5V DC 10 Button 6 (B_PB1) 11 Position 2(B_X) 12 GND 13 Position 3(B_Y) 14 Button 7 (B_PB2) 15 +5V DC 7.7) Serial Port
CadSoft Online: EAGLE Layout Editor PIC18F.COM – Tutorials and Sample Code DisplayPort DisplayPort is a digital display interface developed by the Video Electronics Standards Association (VESA). The interface is primarily used to connect a video source to a display device such as a computer monitor, though it can also be used to carry audio, USB, and other forms of data. The VESA specification is royalty-free. VESA designed it to replace VGA, DVI, and FPD-Link. The first version, 1.0, was approved by VESA on May 3, 2006. Version 1.1a was approved on April 2, 2007 followed by the current standard 1.2 on December 22, 2009. Overview DisplayPort is the first display interface to rely on packetized data transmission, a form of digital communication found in other technologies like Ethernet, USB, and PCI Express. The DisplayPort signal is not compatible with DVI or HDMI. Versions 1.0 to 1.1 1.2 DisplayPort version 1.2 was approved on December 22, 2009. 1.3 Companion standards Mini DisplayPort Micro DisplayPort DDM
Rotational Encoder from old CD motor Rotational Encoder from old CD motor Last updated: September 22, 2010 The spindle motors used in CD-ROM drives often (always?) contain 3 Hall-sensors. These sensors are used by the motor controller to determine the position of the axle. First try to find the connections between the Hall sensors and the motor controller. The Hall sensors are connected in parallel. By feeding the Hall signals into a LM339 you get 3 TTL compatible signals that indicate the axle position. The Hall sensors are permanently connected to Vcc and GND. Rotating the motor gives the following output pattern: 001, 000, 010, 110, 110, 101. A software solution. With microcontroller An attempt to interface the encoder directly to 3 ADC channels of an ATtiny13 microcontroller failed. In a second attempt the outputs of the (already existing) LM339 where connected to the ATtiny13. After the required code change, this worked at first try. AVR programming avrdude -v -P /dev/ppi0 -c stk200 -p t13 -U lfuse:w:0x7a:m