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Re: optical lens
Keith Messent
You could try Messrs Griffin and George, school laboratory suppliers,
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whose Catalogue is on line (if you have enough memory to cope with it!) Keith Messent, Skipton, UK ----- Original Message -----
From: <hazelnutweb@...> To: <Electronics_101@...> Sent: Tuesday, 12 June, 2001 07:25 AM Subject: [Electronics_101] optical lens I am stuck on finding a source of optical lenses |
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optical lens
Hi group, There isn't much information available on laser technology
for the hobbiest. Although I'm an electronics tech, lasers aren't part of my forte. I am stuck on finding a source of optical lenses for experiments. Any suggestions for finding something like a 30-mm diameter, 55-mm focal length plano convex lens? With technicians pay cost is important. ttyl Jim |
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To Tavys
Do you know anybody who did that, some contact or web addressess.
--- In Electronics_101@y..., Tavys Ashcroft <bigtex@c...> wrote: ethernetI am also planning to make a device which can be connected to an problem. Thiscard doing the same thing, eliminating wires. This also has a bandwidths.needs a high quality tranciever which can handle very high regarding the theircircuits I can use .Some students at UC Davis where I used to go had set up their own dorm building. Then with a laptop they could go anywhere on campusgrassy field. |
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Re: Communication device
Tavys Ashcroft
I am also planning to make a device which can be connected to an ethernetSome students at UC Davis where I used to go had set up their own wireless ethernet that way. They hooked up their dorm computer's ethernet to a transceiver and put a microwave antenna on top of their dorm building. Then with a laptop they could go anywhere on campus and pick up the two-way connection. Just like ethernet, no wires. All dorm computers there had shared T1 connection, so it was very fast. It was a hoot to see streaming video in the middle of a grassy field. I didn't find out much about what they actually did, but I know it sure is possible. -Tavys |
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Communication device
I am a computer student and I wanted to do a project in communication
between two computers. I was planning to do dialupnetworking without phonelines. I want to use a wireless device instead of phoneline. A transciever which can be connected to a modem and fool the modem that it is connected to a telephone line. This has a small problem. We will have to produce a dialtone, and when the modem dials the device on the other modem should produce ringing tone. I am also planning to make a device which can be connected to an ethernet card doing the same thing, eliminating wires. This also has a problem. This needs a high quality tranciever which can handle very high bandwidths. If you can help me please send me some additional information regarding the circuits I can use . Waiting for A reply Kenney |
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Re: Remote control ideee....
Tavys Ashcroft
Since nobody really responds to audible car alarms anymore, and everybody hates them, it would make more sense to have the sensors in the car alarm trigger, via RF signals, a message sent to a pager, phone, or audible alarm within the house. This would allow for more discrete notification, and possible tracking of the vehicle. It would also be possible to set up two-way communications between the vehicle and base station in home or cell phone so the owner could yell at the theif personally. That would be fun.
I would love to hear the end of loud car alarms. Especially the Viper ones that cycle through the same tone patterns over and over and over while I'm trying to sleep. -Tavys |
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Re: Business Idea
Tavys Ashcroft
I know lots about sensors and switches, but nothing about wireless andI know a bit about RF stuff, circuit design, machine design, optical sensors, control circuitry, and relay logic, etc. I'm interested in collaborating on this. email: bigtex@... -Tavys |
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Remote control ideee....
Jan Coetzer
Hi Hugh,
Yes, I am interest. This idee have passed my mind before, to install an old cellular telephone in the car (hidden) and then using the AUX socket on the phone interface with the car alarm immobilize. I tried to obtain the pin description on the AUX socket but was not successfully, just to see if it's possible to do. Could someone help, with a URL to obtain the pin layout / description on the Nokia cellphone. Or do I try to hunt rainbows; it would not be possible. Regards Jan |
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Re: need help in Power Supply
Hi, I'm new to this group but old and experienced with electronic
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devices. Have you thought about a surge suppressor for your device? Just a thought! c ya --- In Electronics_101@y..., reniar@c... wrote:
we have a fax machine that is always busted whenever there's a power |
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Re: Business Idea
Dan Ribaudo
I know lots about sensors and switches, but nothing about wireless and
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software. let's talk! email: dan@... -----Original Message-----
From: Hugh O'Brien <aodhobriain@...> To: Electronics_101@... <Electronics_101@...> Date: Thursday, May 31, 2001 2:34 AM Subject: [Electronics_101] Business Idea Hi |
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Re: A3121E Hall Switch datasheet
Giuliani
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----- Original Message -----
From: Sa???a Milovanovi??? To: electronics_101@... Sent: Sunday, January 09, 2005 1:20 PM Subject: [Electronics_101] A3121E Hall Switch datasheet Does anyone have link to this datasheet? Part is: A3121E and it's hall switch... It seems that I'm to dumb to find it on the net! Thanx ! Try here: Bye. Giuliano |
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Re: datasheet
Giuliani
开云体育Roy,
I have saved the data sheet, then
printed, scanned and compressed the first page.
I think it is still readable. It is
150kB. If you want I can send it to your e-mail, and,
if you think it is OK, I can make the
same for the remaining six pages.
?
Bye.
Giuliano
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Re: How to (replace DPCO relays with simple transistros)
Giuliani
开云体育Yes, I have already tested it. Here the
schematic.
?
The 4093 sinks only?a few
microamperes.
?
Bye.
Giuliano
? ----- Original Message -----
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Re: datasheet
Giuliani
Here you can find an old Motorola data-sheet (4.9MB).
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Bye. Giuliano ----- Original Message -----
From: Roy J. Tellason To: Electronics_101@... Sent: Saturday, April 29, 2006 2:53 AM Subject: [Electronics_101] datasheet Any of you guys have, or know where I can find, a datasheet for the chip MC1358? Got one here, and I'd like to know a bit more of what can be done with it... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, a critter that can be killed but can't be tamed. --Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin |
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Business Idea
Hugh O'Brien
Hi
I work as a wireless technology consultant. I have an idea for creating a car/house alarm system that uses wireless technology to alert the user when something is wrong, e.g. their car is stolen. Also allowing the owner to control his car/house remotely, e.g. switch of fuel supply, or turn of lights etc. I think that there is a big market for this. I know alot about the wireless end and software end of things, but not too much about the harware/pherifials/switches side of things. Any one interested. Hugh |
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Re: need help in Power Supply
Tavys Ashcroft
To get 24V DC, you need a transformer which will have a peak (with reference to zero) voltage of just over 24V on the secondary (output). The ammount over depends on whether you're using a two or four diode full-wave rectifier (don't go half wave, you get too much ripple). With the two diode full wave you need a center tapped transformer and the secondary voltage should be about 0.7 volts above what you need (voltage drop across a diode). With a bridge rectifier, you don't need a center tapped transformer and the secondary voltage should be about 1.4 volts above what you need.
I would recommend you get a bridge rectifier. It's essentially four diodes arranged in a ring, within one small package with four pins. You have two pins for AC input and two pins for + and - DC output. I'm sure there's schematics for power supplies all over the internet, so you just need to adjust values to what you need and put them into the schematic you find. There's lots of different ways of setting up filtering and regulation. Basically what you need is a nice big filtering capacitor to remove the AC ripple, and a 24V regulator. You can put both of these in parallel with your DC output. So if you're using a bridge rectifier, you want your secondary peak voltage to be about 25.4 volts, or maybe 26 volts if it's easier to find. But that's peak, not RMS. To convert it, you divide by the square root of two. That's about 17.9 volts RMS. So if you can find a 120V primary / 18V secondary transformer, you should be set. Then you need a regulator and a filter cap. There's some other components, but that's the basics. Look for real schematics online. But I'm no expert here, just a student. I may not yet know enough about power supplies. Test what you get before hooking it up to your fax machine. And make sure you use a regulator, because if not when you test the voltage on something before you hook it up to a load, it will change when you hook it up. -Tavys |
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Need info on Selectronics or other mfr of the SB100 "Sound Bridge" FM transmitter
Ed Miller
Need info on Selectronics or other mfr of the SB100
"Sound Bridge" FM transmitter There used to be a mini FM transmitter made by Selectronics called the "Sound Bridge" model SB100. I would like to know if anyone might have any contact information from that company or the company from whom these units may have been obtained? At one point in time, they were sold by All Electronics and by Parts-Express. I have written to both of these companies with no luck. At some point in time, these units were also given away free to customers ordering a certain CD player or players. If that rings a bell with anyone who might remember which company offered them as a free bonus, that might help me track them down. I'm looking to either order some in quantity, find a company who made them or distributed them, or find a schematic. You can see a photo of this unit at: Thanks very much, William E. Miller, ASEET Chesterfield, Indiana US Need Mfr. Info on SB100 "Sound Bridge" FM Transmitters! See pic @ __________________________________________________ Do You Yahoo!? Yahoo! Auctions - buy the things you want at great prices |
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