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OT: Remote Access.

Started by Jim Thompson in sci.electronics.basics4 hours ago 27 replies

When I'm at my desk I access my Laptop and two PC's via a KVMP switch. With the weather as nice as it is here in the Springtime of...

When I'm at my desk I access my Laptop and two PC's via a KVMP switch. With the weather as nice as it is here in the Springtime of the Southwest (


Van de Graaff device and common sense in physics ...

Started by Anonymous in sci.electronics.basics10 hours ago 11 replies

Van de Graaff device and common sense in physics .... The working principle for Van de Graaff device is analyzed again in this...

Van de Graaff device and common sense in physics .... The working principle for Van de Graaff device is analyzed again in this material: http://elkadot.com/index.php/en/books/electromagnetism/van-de-graaff-device The actual explanation contradicts all we know about triboelectricity. It is impossible for the same belt to come into contact with two identical rollers and to deliver


Selecting from 1% resistors

Started by George Herold in sci.electronics.basics1 week ago 1 reply

I want a 500k resistor 0.1%. It's a prototype so metal film through hole resistors. I got out the bin of 1 Meg 1% er's figuring I could find a...

I want a 500k resistor 0.1%. It's a prototype so metal film through hole resistors. I got out the bin of 1 Meg 1% er's figuring I could find a pair. They were all high, 1.005 Meg was the lowest and 1.015 the highest, with most above 1.01. (And yes my meter works, I've got 1M 0.1% in surface mount and the first one read 1.0004 Meg) I got a 499k and put 1k in series, works fine... ...


Oscillator Proposal

Started by Jim Thompson in sci.electronics.basics1 week ago 16 replies

Oscillator Proposal... Suppose I have a series RLC, one end grounded, the other end driven by a chip, how might I make that into an...

Oscillator Proposal... Suppose I have a series RLC, one end grounded, the other end driven by a chip, how might I make that into an oscillator? All wild ideas accepted... this is for a custom chip. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et ...


Battery choice: 9V vs 6 AAs

Started by Adam Funk in sci.electronics.basics1 week ago 35 replies

I'm fixing a kid's toy that was damaged by corrosion (stored with the batteries). The only damaged part was the battery compartment, so...

I'm fixing a kid's toy that was damaged by corrosion (stored with the batteries). The only damaged part was the battery compartment, so I opened it up, clipped off the internal wires to that bit, soldered extensions on them & ran those through holes in the case, in order to put an external 6 AA holder on. As it turns out, the 6 AA battery holder I bought clips onto a 9 V battery attachment,...


Update: Varistor/MOV Spice Modeling

Started by Jim Thompson in sci.electronics.basics1 week ago 29 replies

Varistor/MOV Spice Modeling has been updated. See VaristorMOV.zip on the Device Models & Subcircuits Page of my website. ...

Varistor/MOV Spice Modeling has been updated. See VaristorMOV.zip on the Device Models & Subcircuits Page of my website. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Sa...


2N3904 maximum ratings Vceo Vcbo

Started by Bill Bowden in sci.electronics.basics2 weeks ago 25 replies

Is it safe to operate a 2N3904 in a switching application with a supply voltage of 48 volts? The data sheet says Vceo is 40 and Vcbo is 60...

Is it safe to operate a 2N3904 in a switching application with a supply voltage of 48 volts? The data sheet says Vceo is 40 and Vcbo is 60 volts. When the transistor switches off, the collector to emitter voltage will be 48 and the base voltage will be near 0 through a resistor. Any problems with that? --- news://freenews.netfront.net/ - complaints: news@netfront.net ---


CMOS logic

Started by Patrick Chung in sci.electronics.basics2 weeks ago

By combining P channel and N channel MOSFET transistor, whole new digital technology, CMOS technology is obtained. Read...

By combining P channel and N channel MOSFET transistor, whole new digital technology, CMOS technology is obtained. Read more: http://www.cirvirlab.com/index.php/electronic/184-cmos-logic-gate-circuits.html


Is there a better way to do this?

Started by default in sci.electronics.basics2 weeks ago 13 replies

I've got some 4KW 240 volt lamp dimmers from China. What I want is a cheap electric range current regulator. (For safety I plan to replace...

I've got some 4KW 240 volt lamp dimmers from China. What I want is a cheap electric range current regulator. (For safety I plan to replace the potentiometers with switched ones and add dual pole contactor - so "off" really is off) The controls I'm replacing use a bimetallic switch with an extra contact to switch off both sides of the 240 line in the off position via a cam on the rotatin...


"Random" Circuit Needed.

Started by Jim Thompson in sci.electronics.basics2 weeks ago 133 replies

For a simulation situation I need a random number generator with a twist... What I need to simulate is a "random" selection of one-of-16...

For a simulation situation I need a random number generator with a twist... What I need to simulate is a "random" selection of one-of-16 outputs. Clock "speed" is 12.5kHz ;-) Built of 74HCxx parts is preferred... I have a full ensemble of those device in my PSpice library. Thanks in advance. ...Jim Thompson -- | James E.Thompson ...


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