Search found 106 matches
- Mon Mar 19, 2007 8:35 am
- Forum: General Discussion
- Topic: Difference between a Crystal, Oscillator, and Resonator
- Replies: 6
- Views: 3481
they have a three-pin crystal shown, but I have not been able to find one. All the crystals seem to be two-pin. It's common to use a two pin crystal with its case soldered to ground, to provide both shielding (against EMI generation) and mechanical support (against external vibration). That may be ...
- Thu Mar 15, 2007 2:04 pm
- Forum: General Discussion
- Topic: Question about resistor tolerances
- Replies: 31
- Views: 12270
- Wed Mar 14, 2007 11:48 am
- Forum: General Discussion
- Topic: Question about resistor tolerances
- Replies: 31
- Views: 12270
- Tue Mar 06, 2007 7:05 am
- Forum: General Discussion
- Topic: AA Batteries are corroding!
- Replies: 13
- Views: 5223
As others have stated you must clean the old corrosion out. Baking soda and warm water is excellent. I clean my car batteries with this mixture probably once a year or maybe once every other year. An old toothbrush works well for this type of job. Baking soda is an alkali, usefull for cleaning an a...
- Mon Feb 05, 2007 10:18 am
- Forum: General Discussion
- Topic: Sensor used for temperature regulating soldering irons?
- Replies: 11
- Views: 4800
Thermistors, diodes, etc are all semiconductors and have a (relatively) low temperature limit. You should use a sensor that is made of metal: either a thermocuple or a wire resistor . If you use some form of PWM or (phase angle) to control the iron's temperature, you may even use the heater's own re...
- Wed Jan 31, 2007 12:55 pm
- Forum: General Discussion
- Topic: Shielding Generator
- Replies: 15
- Views: 12271
Stainless steel (which is high in nickel) seems to be a pretty good shield for both magnetic (magnets don't stick to it) and electric fields (its conductive). (haklesup) Non magnetic materials do not shield magnetic fields. You need a magnetic material. In fact, some submersible deep well pumps are...
- Mon Jan 29, 2007 11:14 am
- Forum: General Discussion
- Topic: Current Indicator Circuit Breaker
- Replies: 14
- Views: 6912
Do you know what formula applies for current transformers? For 1 Ampere AC to yield 1 Volt AC, how many turns are needed (Externet) Current transformers are just that: Current transformers . :shock:. You obtain current, not voltage. If you have a turns ratio of, say, 25 to 1, and you have 25 ampere...
- Wed Jan 17, 2007 1:50 pm
- Forum: General Discussion
- Topic: Current Indicator Circuit Breaker
- Replies: 14
- Views: 6912
- Wed Jan 17, 2007 9:34 am
- Forum: General Discussion
- Topic: Monitoring Water Current direction and speed
- Replies: 19
- Views: 15826
- Fri Jan 12, 2007 9:41 am
- Forum: General Discussion
- Topic: Motors as Generators
- Replies: 21
- Views: 10798
- Fri Dec 29, 2006 5:56 am
- Forum: General Discussion
- Topic: Electrolytic capacitors in series...
- Replies: 20
- Views: 11985
You may use a zenner diode (instead of a resistor) in paralell with each capacitor to act as a safety limit. Choose zenner with a voltage that is slightly less that the capacitor's maximum rating. Add a current limiting resistor between the caps/zenners series and the power supply (the car's electri...
- Fri Dec 01, 2006 6:27 am
- Forum: General Discussion
- Topic: 4050 Non Inverting Hex Buffer
- Replies: 7
- Views: 4062
Looking at the datasheet ( http://www.fairchildsemi.com/ds/CD%2FCD4049UBC.pdf ), the 4050's output can sink 5 mA and source 1.6 mA (typical values @ 25°C). Its max. input current is 1 microA, which gives a DC fanout of :shock: :shock: over 1600 driven devices :shock: :shock: Of course, AC fanout is...
- Thu Nov 30, 2006 9:25 am
- Forum: General Discussion
- Topic: Drill bit sharpening...
- Replies: 16
- Views: 6905
- Thu Nov 23, 2006 6:43 am
- Forum: General Discussion
- Topic: Permanent magnet and field wound motors...
- Replies: 1
- Views: 1376
does a permanent magnet motor uses less power to achieve the same work as an equal wound one because uses no extra electricity to make the field YES, the DC motor converts to mechanical work only part of the power that goes into it's armature winding (converted power = armature current x back EMF)....
- Thu Nov 16, 2006 5:12 am
- Forum: General Discussion
- Topic: 555 timer headaches!
- Replies: 31
- Views: 12853