Electronics Forum / Basics / June 2007

I have a dell laptop that won't power on or charge the battery but
ran fine on battery until the battery lost its charge . I checked the
DC output of the AC adapter with a multimeter and it constantly
fluctuates from 18.5v - 19.5v.

I have an analog switch question. For this example, I would like to
use Texas Instrument's TS5A3159A SPDT Analog Switch.
For the digital input (triggers the switch ON or OFF), it has the
following electrical characteristics:

I have a simple, but curious question about an op-amp specification:
input offset voltage vs. time.  I see this specified as uV/mo.  Is
this caused by general aging of the part; i.e., regardless of being
powered on or stored on a shelf?

Hello everyone I'm new to this I just wondering if you guys can help
me out. I'm trying to build a circuit but I don't know were to begin
or what components I should use. I need to the circuit to deliver
current to a TE modules which will be heating up a liquid once the

Greetings everyone,
I am a rank amateur with electronics. I have found a Battery Isolator
schematic at Discover Circuits.com and I would like to build one of
these. I understand what I’m doing but not sure how to do it. I

I am interfacing an PIC microchip to a relay by using a normal NPN
transistor. The relay is connected between +12v and collector. A
protection diode in reverse has also added. Emitter is grounded. My
concerne is that by only adding a 10k resistor between base and the

Greetings All,
I have an electronic thermometer that uses a piezo speaker for an
audio alert when the temperature reaches a certain point. I would like
to use the output to the piezo device to actuate a relay. I think the

Greetings All,
This link:
http://www.vellemanusa.com/downloads/0/manual_mk138.pdf
is the schematic for a thermostat kit I built. Even though it works I

Could four of these TRIACs be used to build an H-bridge?
http://www.mouser.com/search/ProductDetail.aspx?R=Z00607MA_1BA2virtualkey5112000
0virtualkey511-Z00607MA
I'm only planning on using 100mA max.
Thanks,

Live on a deserted island the rest of your life...
Not have sex or masturbate the rest of your life...
or
Not be able to talk for the next 10 years?

Good day
I have a little problem with my ground fault always tripping.
I have an above ground pool with a 1hp pump.  I have a wire in a
conduit to the pump.  The wire is 14/2 and is about 100 ft from the

Who manufactures SD, miniSD, and microSD memory?  These memories are sold
under many names, yet I am trying to find a manufacturer, or a wholesaler.
Thank you.

Hi,  I was looking at the following circuit:
http://static.flickr.com/56/145174497_d31b603880.jpg
and I was wondering why the transistor is used in the first place.  From
what I can see, it is used to amplify the current in order to drive the

I am winding an electromagnet  with some 29awg magnetic wire. I want
to make to electromagnet with the same strength, but one core is about
3 time as big as the first. With the small core I get 185 Amp-turn
with 480 turn (31ohm).

Is there any problems with applying a reverse V that is <= Vr of an
LED? I'll limit it through a 10K resistor also....
Thanks,
John