Design

Remote IR on-off switch
I've come across this DIY IR remote on-off switch design more than once with only minor variations. http://img109.imageshack.us/img109/6399/irswitch.png It looked OK at first, but then it seemed to me that R3 and D1 are not really needed. Why not just omit R3 and short out D1 as on the right side of image? ... 17 Feb 2010 19:04

Soldering Iron Recommendations?
I have an absolutely ancient Weller WTCPN soldering station that is disintegrating... it's probably at least 33 years old. I don't have any need for surface mount sophistication. What are people's thoughts on a cheapy replacement such as... Weller WLC100 Soldering Station ... 20 Feb 2010 05:52

Heatsinking surface mount high power MOSFETS
<oparr(a)hotmail.com> wrote in message news:46b86706-7a79-4d41-a104-a443f64785f0(a)b18g2000vba.googlegroups.com... What are high power MOSFETs in DPAK and D2PAK packages good for when one can get the TO-220 equivalent? Why pay for capability that you will never realize? I can see these packages being useful in l... 17 Feb 2010 00:22

LTSpice Automation
Does LTSpice have much in the way of automation capabilities? I'm working on a switcher design, half in mathemagic land, half in grotty old real circuits land -- I want to simulate the controller with PWM voltages, and look at how the circuit responds. So I'd like to run the circuit with a bunch of different ... 22 Feb 2010 14:09

240V AC power switch - based on current drawn from outlet
Hi! I was wondering if anyone could give me a few hints / pointers on building blocks in the following design / idea: I have a few powertools that generate dust; circular saw, sanding machine, etc. And, I have a dust extractor / vacuum cleaner. My idea was that instead of hearing the constant buzz from the ... 15 Feb 2010 12:04

Ohm's Law Problem
Ohm's Law Problem: Find the voltage at the 2 junctions of a 3 element voltage divider across a supply voltage of 8.4 volts. The two junctions of the divider both supply external current of 5mA. +8.4 | R1 = 240 | .---------> 5 mA | R2 = 570 | .---------> 5 mA... 18 Feb 2010 13:58

A novel way to measure magnetic fields, and DC current withouta shunt?
Am 14.02.2010 23:16, schrieb Jan Panteltje: .... I think this way: I get a delta f of 82000 Hz for a 0-1.2 Tesla at the front of the inductor. So about 68 Hz per milli Tesla. A standard AMR magnetometer (Honeywell makes some) for less than 5� has a resolution of 7 mGauss. (Turn it on... Ok, the 48�T of... 17 Feb 2010 00:22

Fast And Gate, 1 Ghz
Can anyone suggest a fast AND gate at 1-2 Ghz. A friend of mine needs to measure a laser pulse duration on almost no budget, perhaps 200-300$. The Pulse ranges from 4 to 20 Nanoseconds, and his current idea is use the photodiode current to gate open a source of 1 ghz pulses and integrate,. The 2 Ghz source is the ... 18 Feb 2010 21:50

Protecting 3x16 bits with 16 bits ? (crc8 + 8 bit hamming code seems perfect)
Hello, I just had a better idea, since I forgot about the address check... Since a hamming code has a certain range I might as well use the full range to "ham" more bits ! ;) :) So there are 48 "gpu data bits" and the maximum addressing range is probably "16 bits" So that creates a total of: 48 true dat... 13 Feb 2010 23:49

A different idea from A More Efficient Bridge Rectifier?
On Feb 9, 5:06 pm, D from BC <myrealaddr...(a)comic.com> wrote: My offline smps design has 3 parts making the most heat. A power diode, a mosfet and a bridge rectifier. I'm interested in any cookbook designs that replaces a bridge rectifier. Any pointers? Imagine the no input ripple version of the tra... 22 Feb 2010 02:00