Search found 1182 matches

by Bob Scott
Sat Mar 24, 2012 12:02 pm
Forum: General Discussion
Topic: Looking for H Bridge driver
Replies: 1
Views: 820

Re: Looking for H Bridge driver

Hi Ian,

Take a look at bridge drivers from IR. That's their main business: Power MOSFETs, drivers, app notes, tech tips.

http://www.irf.com


WOW, no one else answered you in a week. This forum must be dying.
by Bob Scott
Fri Mar 02, 2012 9:23 am
Forum: General Discussion
Topic: Transmitter Modulators
Replies: 68
Views: 20172

Re: Transmitter Modulators

I have a simple explanation for describing the modulation products of the signals Robert described. The type of modulation is double sideband suppressed carrier. On positive portion of the modulating signal the carrier is in phase with the supplied carrier. On negative portions of the modulating sig...
by Bob Scott
Wed Jan 18, 2012 9:02 am
Forum: General Discussion
Topic: led power supply questions...
Replies: 5
Views: 1368

Re: led power supply questions...

i have seen led power supplies of constant current and constant voltage. when and how should these be used. in what situations should one use CC or CV ? There are times when a constant voltage source would be completely inappropriate, like the supply for a neon bulb or fluorescent tube. eg: The neo...
by Bob Scott
Mon Jan 09, 2012 5:27 pm
Forum: General Discussion
Topic: FLUKE METER Model 8060A True RMS Multimeter
Replies: 14
Views: 2251

Re: FLUKE METER Model 8060A True RMS Multimeter

Hey Edd! Long time no see!

Only 4 posts since 2008? Welcome back. Don't leave again. :grin:
by Bob Scott
Wed Dec 28, 2011 11:41 am
Forum: General Discussion
Topic: Florescent light problems
Replies: 6
Views: 1234

Re: Florescent light problems

anyway the cure i made to make sure the lights light up every time was i ran a stripe of thin metal foil tape about 3/8 wide down the full length of each tube. no more problems.. you can try that, and make sure the fixtures are grounded. what type of fixtures are they ? ( bulb type , type of ballas...
by Bob Scott
Sat Dec 24, 2011 12:48 pm
Forum: General Discussion
Topic: MERRY CHRISTMAS and a HAPPY "SAFE" NEW YEAR
Replies: 6
Views: 1766

Re: MERRY CHRISTMAS and a HAPPY "SAFE" NEW YEAR

Aahh, yes. It is just wonderful to take some time to share good food, good drink, good friends and good cheer. To everyone- "Have a Holly Jolly Christmas" ala Burl Ives. (I just love that song and only he could sing it) I was thinking the exact same thing earlier today! Burl had a very unique voice ...
by Bob Scott
Fri Nov 18, 2011 9:25 am
Forum: General Discussion
Topic: Transconductance S ?
Replies: 3
Views: 976

Transconductance S ?

Hi all, Can someone please explain how to calculate the S unit used as a value for transconductance? An example would be in the data sheet for the IRFZ44 MOSFET. Is it as simple as Volts of input per Amp of output? Then there is the S unit used in functions for frequency filter caclulations. I don't...
by Bob Scott
Fri Nov 18, 2011 9:11 am
Forum: General Discussion
Topic: Lights of America does not play well with GFCI
Replies: 20
Views: 2820

Re: Lights of America does not play well with GFCI

i did all the wiring myself, all is correct, the outlet tester shows all to be correct. the light fixtures all came with prewired cord attached. i can take the light and try it on any other gfci outlet in the house and it trips also.. i opened a fixture, and they are also wired correctly. L.O.A. ha...
by Bob Scott
Sat Oct 29, 2011 7:27 am
Forum: General Discussion
Topic: Three pin 12V regulators...
Replies: 9
Views: 1320

Re: Three pin 12V regulators...

Hi Guys. I found some at alldatasheet.com. I was pointed there by google.com. 78L** 0.1 Amp TO-92 pkg 78M** 0.5 Amp TO-220 and SMT 78** 1 Amp TO-220 78H** 5 Amp TO-3-like pkg 78S** 2 Amp TO-3 TO220 78T** 3 Amp TO-220 (I found the Motorola mfg data sheet.) I suppose 3 Amps is the most that they want ...
by Bob Scott
Thu Oct 27, 2011 8:50 am
Forum: General Discussion
Topic: Interesting constant current component...
Replies: 1
Views: 532

Re: Interesting constant current component...

I suppose it is a voltage regulator in current mode Miguel I think that it is just a garden variety P or N channel JFET with the Gate shorted to the Source to make a 2 terminal constant current source. It is dressed up in a different package. I remember seeing a data sheet with a JFET wired like th...
by Bob Scott
Tue Oct 25, 2011 5:07 pm
Forum: General Discussion
Topic: Power mains spikes and surges and...
Replies: 7
Views: 1262

Re: Power mains spikes and surges and...

OK. I will get several of these : http://parts.digikey.com/1/parts/1903501-varistor-140vrms-22ka-radial-v25s140p.html That's the one you want, a MOV. Our transmitter technician went out to repair a remote transmitter in a rural location. Blowing wind had tangled the power lines along the drop, and ...
by Bob Scott
Thu Oct 13, 2011 11:55 pm
Forum: General Discussion
Topic: Your orphan laptop LCD screen...
Replies: 10
Views: 1380

Re: Your orphan laptop LCD screen...

Hi Miguel,

What would you do with these boards? I see they do PAL and SECAM analog video. I don't see NTSC or ATSC. (??) :???:
Also, I see a tuner block but not frequency specifications.
How would they connect to an old laptop screen?
by Bob Scott
Mon Oct 10, 2011 4:05 pm
Forum: General Discussion
Topic: Evaluating to start a project or not...
Replies: 8
Views: 1321

Re: Evaluating to start a project or not...

Tinkered with ideas of a 30dB cable TV booster for $6 but still see no light. Cannot repeat on the same frequencies received. And no way am running a RG-6. Miguel I once pondered retransmitting TV channels with a cable TV "apartment amplifier". They output up to +45dBmV or so (Voltage X 180) with a...
by Bob Scott
Mon Oct 03, 2011 5:57 pm
Forum: General Discussion
Topic: Starting a project, solar powered night light
Replies: 29
Views: 5519

Re: Starting a project, solar powered night light

I remember a project in Radio Electronics called "Solar Powered Night Light". I believe it was April 1971 or 1972. Of course it was an April Fools' project (no battery), along with a windshield rain detector to tell you when to turn on your wipers. :grin:
by Bob Scott
Tue Sep 27, 2011 8:39 am
Forum: General Discussion
Topic: Generator Question
Replies: 20
Views: 2941

Re: Generator Question

VW Toureg 5.0 V10 TDI (Turbo Injected Diesel) Maximum torque is at 2000 RPM, close enough to 1,800 that it looks like it was made for the job! http://www.team-bhp.com/forum/iipcache/7615.jpg This would make an excellent engine for a high power backyard backup jenny. From the torque curve, I calculat...