Search found 2095 matches

by jwax
Thu Mar 11, 2004 5:28 pm
Forum: General Discussion
Topic: spark plug voltage
Replies: 5
Views: 1145

Re: spark plug voltage

Don't! Sure fire way to fry your multimeter! Without serious monitoring equipment, you won't measure anything significant. Remove the plug from the head, ground its' threads, and yank away. Bright blue spark at gap says all is well. Wanna get fancy? Build a spark gap- two nails pointed at each other...
by jwax
Wed Mar 10, 2004 3:47 pm
Forum: Computer Programming
Topic: data logger for a temperature sensor
Replies: 2
Views: 1751

Re: data logger for a temperature sensor

GW- Try:
http://www.omega.com/newsearchengine/es ... mit=Search<p>Omega has loads of temp sensors/loggers/accessories.
Have a blast!!
John
by jwax
Tue Mar 09, 2004 3:01 pm
Forum: General Discussion
Topic: Magnetrons
Replies: 5
Views: 861

Re: Magnetrons

Those microwave power supplies make wonderful supplies for that Tesla Coil project your neighbors don't want you to build! :D
by jwax
Sat Mar 06, 2004 7:09 pm
Forum: General Discussion
Topic: Best FET to use?
Replies: 9
Views: 1522

Re: Best FET to use?

Big project, Bern! I bought a Curtis DC Controller for an electric go-kart I built. 48 volt @ 200 Amps, and that was for a 1 HP DC motor. It used 8 MOSFETS. You'll have thermal considerations, load-sharing, shut-down protection, to name a few. If you still pursue building your own, one source is Adv...
by jwax
Fri Mar 05, 2004 3:57 am
Forum: General Discussion
Topic: UHF TV antennas
Replies: 12
Views: 1960

Re: UHF TV antennas

Thanks Dean! I appreciate your insight!
John :D
by jwax
Mon Mar 01, 2004 3:19 pm
Forum: General Discussion
Topic: Connecting Portable CD player to car radio
Replies: 5
Views: 1022

Re: Connecting Portable CD player to car radio

Or for $20, the RS will sell you a "CD-to-Cassette" Adapter- cat. no. 12-1999.
(Assuming your car radio has cassette)
by jwax
Sat Feb 28, 2004 6:09 am
Forum: General Discussion
Topic: Wireless Remote Control troubleshooting question
Replies: 15
Views: 2803

Re: Wireless Remote Control troubleshooting question

Rather, using 12 vdc my have fried them.
by jwax
Sat Feb 28, 2004 6:07 am
Forum: General Discussion
Topic: Wireless Remote Control troubleshooting question
Replies: 15
Views: 2803

Re: Wireless Remote Control troubleshooting question

Am I missing something? Both TX and RX are rated for 5 vdc supply maximum!
Using 6 lithiums in series may have cooked them both.
by jwax
Thu Feb 26, 2004 4:44 pm
Forum: General Discussion
Topic: Wireless driveway alarm
Replies: 14
Views: 2276

Re: Wireless driveway alarm

$349 Canadian for the 1000 ft unit?
I'll build and sell you the same thing for half of that! How many do you want to order? :D
by jwax
Thu Feb 26, 2004 4:27 pm
Forum: General Discussion
Topic: WARNING LIGHT CIRCUIT
Replies: 5
Views: 1114

Re: WARNING LIGHT CIRCUIT

Apply the incoming 24 volt pulse to a relay. Wire the contacts of the relay to connect the 24 volts to its coil, keeping it "latched" on, while another set of contacts is keeping your other lamp on. Then pushing a "normally closed" switch in the coil circuit will interupt the relay, causing it to dr...
by jwax
Wed Feb 25, 2004 3:56 am
Forum: General Discussion
Topic: Automotive dual battery question
Replies: 29
Views: 4696

Re: Automotive dual battery question

My, my! Let's expand on the proportions. Say the passenger side battery is 2 feet away from the starter with 2/0 cable. The drivers side battery is connected by 4 ga, in say, the next county. Same current from each battery? I don't think so. Most of the current from the drivers side is lost as IR dr...
by jwax
Tue Feb 24, 2004 3:25 pm
Forum: General Discussion
Topic: Automotive dual battery question
Replies: 29
Views: 4696

Re: Automotive dual battery question

Where's that guy with the strap-on ammeter?
The large, close cable (passenger side) will carry most of the current.
by jwax
Sun Feb 22, 2004 7:10 pm
Forum: General Discussion
Topic: UHF TV antennas
Replies: 12
Views: 1960

Re: UHF TV antennas

Thanks, all! Looks like I have a Yagi to build!
I appreciate the info, and love a challenging project! ;)
by jwax
Sun Feb 22, 2004 3:09 pm
Forum: General Discussion
Topic: searching for 1.5 volt led low ma for battery charge ind
Replies: 11
Views: 2215

Re: searching for 1.5 volt led low ma for battery charge ind

http://www.marktechopto.com/index.cfm?a=138
That's the link to the voltage/current plot I tried to picture. Sorry.
by jwax
Sun Feb 22, 2004 3:04 pm
Forum: General Discussion
Topic: searching for 1.5 volt led low ma for battery charge ind
Replies: 11
Views: 2215

Re: searching for 1.5 volt led low ma for battery charge ind

Image
Here's a typical LED voltage/current plot.
Note it doesn't draw any current until the applied voltage reaches 1.8 volts.
www.solarworld.com has a great collection of solar cells.