Design

SG3524 switcher problem
I built variable switching power supply using schematic from this address: http://delabs.netfirms.com/cirdir/power/del20020.pdf I don't know if this schematic has any bug, but my switcher which is built using this schematic not works good :( I checked, and rechecked all connections several times, but everything... 25 Feb 2006 16:59

Open Source Thermostat and more (Schematics)
I've just put up a very basic (schematics only at this time) site. There are currently four projects: www.myblueroom.com Cricket Communicating Thermostat (IR, iButton, RS232 or 485) Ladybug Super IO Controller (RS232 & RS485, RTCC with 24hr backup, 6 relays, 3 digital & 1 digital/analog input, 1 iB... 21 Feb 2006 02:37

4 digit LCD or LED display
I'm looking for a 4 digit LCD or LED display to use with a PIC processor. Something easy to use that will latch 4 bit data from the processor to each of 4 (7 segment) digits. Anybody know of a part number and supplier? -Bill ... 24 Feb 2006 23:47

Timing Circuit
I need to design a circuit that I can tell it to start (digitally), and then it will tell me when 10 minutes have passed. I just need to be pointed in the right direction. What's the difference bewteen a timer/clock/counter. I have a good understanding of circuit theory but does anyone know of a good IC that can... 1 Feb 2006 11:25

DTMF Decoder IC
I'm looking for DTMF decoder chips and I am having a lot of trouble finding any. Some of the part numbers I have searched are TDK's SSI-220, or G8870 Any available DTMF decoder will do the job. Does anyone know a place where I could definetly find some? Thanks ... 30 Jan 2006 18:04

Potential Transformer
Hello all! I am currently working on my senior design project of a Digital Power Meter here at the South Dakota School of Mines and Technology (Shamless plug!). I plan to measure and display Voltage, Current, Power and Power Factor. To do this I plan to sample both waveforms and calculate the rest. I have f... 24 Jan 2006 11:40

Chipset for wireless switch??
Hello Group Is there a chip-set or a low-cost and simple solution to make a wireless switch. What I'm trying to do is add a brake light to my sleigh (which is required) behind my snowmobile without having a wire harness. I was planning on using leds and a battery for the sleigh The snowmobile has power of coarse... 10 Jan 2006 16:05

Complete Current Induction Heater Schematics
http://webpages.charter.net/dawill/Images/Induction11.gif http://webpages.charter.net/dawill/Images/Induction12.gif http://webpages.charter.net/dawill/Images/Induction13.gif http://webpages.charter.net/dawill/Images/Induction14.gif http://webpages.charter.net/dawill/Images/Induction15.gif I'll put 'em in a web p... 9 Jan 2006 17:32

RF Input Matching Network for TEA5768?
Hi, I was going to the appliation note for the TEA5768 and I can't seem to figure out how they came up with this matching network: http://img391.imageshack.us/my.php?image=tea5768rfmatchckt1bd.jpg The image shows 3 pin connections to an LNA. The application note states that "the input impedance of the LNA is... 6 Jan 2006 09:22

NPN Common Emitter Bias
Can an NPN transistor in a common emitter configuration be safely biased for standing DC current WITHOUT having an emitter resistor in the circuit, i.e emitter directly tied to ground? I'm trying to accomodate a 12 volt peak swing on the collector with only a 12 volt supply available. Any emitter resistor obvi... 7 Jan 2006 09:20