Search found 543 matches
- Fri Jul 02, 2004 6:35 pm
- Forum: General Discussion
- Topic: High-quality resistors
- Replies: 14
- Views: 6108
Re: High-quality resistors
All resistors produce noise, depending on the temperature and bandwidth and resistance. Metal film resistors are probably close to the theoretical noise while carbon composition resistors are more noisy.
- Thu Jun 10, 2004 7:26 pm
- Forum: General Discussion
- Topic: Circuit help: 5-0v scaled the 0-1v
- Replies: 7
- Views: 3721
Re: Circuit help: 5-0v scaled the 0-1v
I posted a schematic on my website. You may have to copy and past the URL because Geocities does not allow links. http://www.geocities.com/russlk/vcnv.jpg <p>I forgot the divider resistors for .833 volts. They are connected from 5 V to gnd and are: 49.9K and 10.0K.<p>[ June 10, 2004: Message edited ...
- Thu Jun 10, 2004 6:43 pm
- Forum: General Discussion
- Topic: Wireless communication underwater
- Replies: 4
- Views: 2728
Re: Wireless communication underwater
I don't know anything about BIM2, but underwater communication is usually done at low frequency. The US Navy communicates with submarines at 10kHz.
- Sun Jun 06, 2004 7:58 pm
- Forum: General Discussion
- Topic: old printer
- Replies: 3
- Views: 2186
Re: old printer
It would be simple in DOS, but DOS doesn't know about USB. Windows dumps the print file to a spooler and processes it in background while you are doing something else. So, getting a Windows printer to do something simple like move one line, is not so simple.
- Sun Jun 06, 2004 7:47 pm
- Forum: General Discussion
- Topic: Ignition Noise
- Replies: 10
- Views: 4604
Re: Ignition Noise
The noise may be radiated to the antenna, check the grounding strap for the hood. Also, if you have old, leaky spark plug wires, these will make a lot of noise.
- Thu Jun 03, 2004 2:31 pm
- Forum: General Discussion
- Topic: looking for schematic / plans
- Replies: 15
- Views: 7006
Re: looking for schematic / plans
The MC14543B is a BCD to 7-segment decoder that can drive either common anode or common cathode. It is available from Digikey.
- Thu Jun 03, 2004 2:07 pm
- Forum: General Discussion
- Topic: interface problem
- Replies: 4
- Views: 2744
Re: interface problem
If both are running on 5 volts and the grounds are common, it must be a coding (programming) problem.
- Wed May 19, 2004 7:29 pm
- Forum: General Discussion
- Topic: Caller ID
- Replies: 6
- Views: 3658
Re: Caller ID
It has been a few years since I bought them, but NTE has 7 segment LEDs 1 inch high, part no: NTE3080.
- Wed May 19, 2004 7:18 pm
- Forum: General Discussion
- Topic: Hall effect sensors
- Replies: 6
- Views: 3433
Re: Hall effect sensors
It is actually a hall effect IC with an open collector output.<p>Allegro makes a sensitive linear hall effect, part number: UGN3503UA.<p>[ May 19, 2004: Message edited by: Russ Kincaid ]</p>
- Wed May 19, 2004 7:12 pm
- Forum: General Discussion
- Topic: connecting motors
- Replies: 13
- Views: 6374
Re: connecting motors
A normal motor has only speed control, you can't position it without a feedback system. Such a system is called a servo and is a field of study by itself. The stepper motor makes precise movements without feed back, so it is simpler, system-wise but the driving electronics is more complex.
- Fri May 07, 2004 6:49 pm
- Forum: General Discussion
- Topic: Antenna Rotor Controller
- Replies: 5
- Views: 2847
Re: Antenna Rotor Controller
The narrow end of the antenna is the front, but it will receive from the back also (just not so good). My Radio Shack controller has 3 terminals, see if you can find one of those.
- Fri May 07, 2004 6:40 pm
- Forum: General Discussion
- Topic: how to check a tank circuit
- Replies: 8
- Views: 3731
Re: how to check a tank circuit
Your 30 mHz scope is not going to be any use. If you have a receiver that will tune the frequency, you can hear the quieting that happens when you tune to the unmodulated carrier, or you can modulate it and listen for the modulation. If you just want to know if it is oscillating, measure the base an...
- Sun May 02, 2004 4:21 pm
- Forum: General Discussion
- Topic: Metal detecting
- Replies: 20
- Views: 10107
Re: Metal detecting
Most cheap metal detectors use the BFO system with a single coil. I doubt it would be sensitive enough for you. The 3 coil system is the best bet but I have no experience with it. There is another system called pulse induction but I tried that with no success.
- Mon Apr 26, 2004 7:36 pm
- Forum: General Discussion
- Topic: 24 VDC to 5 VDC
- Replies: 9
- Views: 4483
Re: 24 VDC to 5 VDC
If the load is under 1 amp, Linear Technology should have an IC, check out this URL: http://www.linear.com/prod/datasheet.html?datasheet=260
- Sat Apr 17, 2004 6:59 pm
- Forum: General Discussion
- Topic: 350T Power pulse generator. Rate or amplitude?
- Replies: 8
- Views: 3848
Re: 350T Power pulse generator. Rate or amplitude?
It seems to me that you are trying to make an open loop servo. That approach will be frought with problems. Is this motor going to oscillate back and forth (like a windshield wiper)? Or, will the motor turn and stop, holding a position? What I think you need is a position servo, but I need more info...