Design

Looking for 1kpcs of MK484
Hi All, Is the AM radio receiver IC MK484 (aka AN414) still in production? Are there any other alternatives? Regs Joey ... 20 Dec 2009 18:01

One zener diode vs two standard diodes for overvoltage protection of low-level voltage (analog and data) lines...
On Thu, 17 Dec 2009 08:40:34 -0800 (PST), rfmg <francomendoza79(a)hotmail.com> wrote: On Dec 17, 5:19�pm, Jan Panteltje <pNaonStpealm...(a)yahoo.com> wrote: On a sunny day (Thu, 17 Dec 2009 07:48:38 -0800 (PST)) it happened rfmg <francomendoz...(a)hotmail.com> wrote in <f4fb3d38-b3dd-4269-9e33-6d39c5ae0...@d... 17 Dec 2009 19:18

Learning Mosfets...RdsON Warm Up?
I got a 10 ohm carbon switched by a mosfet(TO-220). Spec sheet: Rdson=0.17ohms at 9.8amps with <=300uS pulse 2% duty. R to drain. Source to gnd. 20V regulated supply On the scope I've noticed that Vdson is still increasing in voltage (Ids still increasing) after a 50uS mosfet turn on time. (Freq=10xper sec... 21 Dec 2009 21:22

Favorite jellybean ~HF BJT?
2N2369 is an old standby... kind of high current (200mA), like a '3904 sped up about 2-3 times. Not well specified though, I suppose because it's so old. I'm thinking in the 20V, 50mA range, fT maybe 0.5-1GHz. Like if you wanted to make old school RTL circuits that run as fast as 74S TTL. MPSH11 looks good,... 17 Dec 2009 22:36

One zener diode vs two standard diodes for overvoltage protection of low-level voltage (analog and data) lines...
Hi guys, I am working on a design where I have a couple of analog (ADC) lines measuring a range between 0V and 3V3, and a couple of digital data lines transmitting/receiving 0V and 3V3 voltage levels, and I want to protect them from overvoltage. Hence, I was wondering if you have any reference to read about ... 20 Dec 2009 07:05

comparing fourierspectra of signal and noise
In the literature concerning noise it is written that as the fourier transform is not defined for a noise signal, one should first take the autocorrelation of the noise signal and then apply the fourier transform. When I look at the units of these operations this will give me a result in Volt^2/Hz. If however I hav... 19 Dec 2009 08:22

Use different size wire in electro clutch?
The coil in an industrial electromagnetic clutch (connecting the flywheel to the drive mechanism) has gone open-circuit. So it is being rewound by a motor rewind shop. I was just informed that the original wire was about 12 ga. (maybe slightly larger; original was metric) but it was rewound using 10 ga. Sh... 26 Dec 2009 17:40

Microphones in parallel to reduce noise
My boss laid a unit on my desk today. Its got ten electret mics fed into one low noise opamp. Any ideas how they did this without a ton of noise. All I can see from the board layout is it is NOT the classic op amp summer. Any suggestions for papers on low noise signal combining? Steve ... 23 Dec 2009 19:39

Hoperf radio modules and DNS
I've just designed in a radio module RFM12B-433-S1 from hoperf (www.hoperf.com). Now I cannot access the hoperf website. In fact DNS doesn't resolve the name (either with my DNS servers or online nslookup). Should I be worried? This is a Chinese company and these modules seem to be very popular. They might be ch... 16 Dec 2009 19:06

Linear phase 50Hz notch filter
Can anyone provide information on implementing a 50Hz notch filter for data acquisition that operates without phase distortion? This could be a circuit or dedicated linear phase filter IC. Harold Keller ... 20 Dec 2009 14:42