Search found 2856 matches

by haklesup
Mon May 24, 2004 6:54 pm
Forum: General Discussion
Topic: Mystery Transistor - is Dr. Sherlock Holmes out there?
Replies: 8
Views: 1875

Re: Mystery Transistor - is Dr. Sherlock Holmes out there?

Most high power audio amps schematics I have seen (any worth building that is) are based on FETs anyway. The BJT transistors you have would be better placed in a linear power supply or something similarly DC.<p>Timothy, that happens to me sometimes. It's the punctuation A colon followed by a "D" wil...
by haklesup
Mon May 24, 2004 6:43 pm
Forum: General Discussion
Topic: Do I need a diode here?
Replies: 7
Views: 1884

Re: Do I need a diode here?

You can probably bias the coil on that automotive relay either way and it will pull in the arm and make the switch. A doide is certainly not needed to protect the relay, the switch or most automotive power systems. I would encourage a fuse on the coil loop and the load loop (switch contact side) sep...
by haklesup
Fri May 21, 2004 2:42 pm
Forum: General Discussion
Topic: Caller ID
Replies: 6
Views: 1421

Re: Caller ID

Maybe, I haven't read the datasheet enough. It does seem to have a way to attach a keypad for dialing and does store numbers gotten from CID but I am not sure if you can store your own numbers or how you would trigger the circuit to take the phone off hook and start dialing to say nothing about dial...
by haklesup
Fri May 21, 2004 2:19 pm
Forum: General Discussion
Topic: Boost 12V to 60V
Replies: 5
Views: 1036

Re: Boost 12V to 60V

You cannot boost the voltage of DC without first going to AC as is done in the a DC-DC converter. I wouldn't exactly call it Linear since it has more in common with a switcher but it will do the job and is standard fare in most high powered audio amps as with a 4ohm speaker and 12V you could only ge...
by haklesup
Thu May 20, 2004 5:24 pm
Forum: General Discussion
Topic: Caller ID
Replies: 6
Views: 1421

Re: Caller ID

Chips like this HT95168 are fully integrated and include the LCD driver on-chip. All you need to do is select an appropriate LCD display and your practically done. You can find all sorts of LCD displays and you may be able to adapt an LED display if you build a buffer to boost the drive current.<p>I...
by haklesup
Tue May 18, 2004 3:28 pm
Forum: General Discussion
Topic: Mystery Transistor - is Dr. Sherlock Holmes out there?
Replies: 8
Views: 1875

Re: Mystery Transistor - is Dr. Sherlock Holmes out there?

Other than knowing it was packaged in Mexico on the 31st week of 1986 by motorola the part number is not one of their standard lines. It may be a house number and you would need to go to the equipment manufacturer to cross it with their schematic (good luck). I checked several databooks and could no...
by haklesup
Tue May 18, 2004 2:54 pm
Forum: General Discussion
Topic: Battery Backup for Clock Radio
Replies: 5
Views: 1586

Re: Battery Backup for Clock Radio

I have actually had corroded back up batteries reduce the useful life of some products. If you rarely have a power failure it is easy to forget that the battery in the clock may be several years old.<p>As a manufacturer, it may be better to force your customers to reset the clock than it is to get c...
by haklesup
Tue May 18, 2004 11:18 am
Forum: General Discussion
Topic: power point
Replies: 4
Views: 1072

Re: power point

I suppose the cigarette lighter versions would be more heavy duty because of the need to withstand heat but it should be electrically equivelent to one made as a accessory outlet only. The metals plated on the contact surfaces of the connector and the mating plug would play into the performance the ...
by haklesup
Wed May 12, 2004 5:20 pm
Forum: General Discussion
Topic: 1.5 volt clocks
Replies: 5
Views: 1136

Re: 1.5 volt clocks

A typical AA battery might have a capacity of 1300mAh while the clock chip may only consume 200uA (more or less depending on the display and if there is a backlight) at that rate the battery should last 6500 hours or about 541 days. These values are just an estimate but you can see how it goes. LCD ...
by haklesup
Wed May 12, 2004 12:31 pm
Forum: General Discussion
Topic: GPS Tracking Device
Replies: 6
Views: 1825

Re: GPS Tracking Device

The DeLorme offering is pretty good but you have to use it with a PC. It looks a little like a mouse and has no user interface which keeps the price down (but the included software just jacks it right back up).<p>The little Garmin eTrex has several models and the basic one can be found for <$100. Wi...
by haklesup
Tue May 11, 2004 2:05 pm
Forum: General Discussion
Topic: Transistorized water flow?
Replies: 18
Views: 3880

Re: Transistorized water flow?

Nothing less than a "Rube Goldberg" machine is required here. It looks like you will need a large cistern, an IR laser w photo sensor(used to sense temp and level of the water), several hundred feet of various kinds of tubing, a bag of 555 chips, 1 foot-3cm of Nitonal wire and a 500W power supply pl...
by haklesup
Sun May 09, 2004 12:58 am
Forum: General Discussion
Topic: AFT wont lock
Replies: 7
Views: 1192

Re: AFT wont lock

I bow to you Edd. You could not have been more correct. I found the cold solder joint on the exact component you described. See the picture<p> http://www.ultratest.com/NV/Cold%20Solder.JPG <p>Now the tuner locks in just fine.<p>On to the next problem with this set. The On Screen Display (OSD) does n...
by haklesup
Sat May 08, 2004 2:34 pm
Forum: General Discussion
Topic: Transistorized water flow?
Replies: 18
Views: 3880

Re: Transistorized water flow?

Don't know much about muscle wire but it sounds expensive and hard to get. One waekness is that it requires constant power to regulate (squeeze) to less than max flow. If you loose power, the water goes to max.<p>Do you think a servo motor from an RC toy would have enough torque to turn a screw on a...
by haklesup
Fri May 07, 2004 3:54 pm
Forum: General Discussion
Topic: Antenna Rotor Controller
Replies: 5
Views: 1149

Antenna Rotor Controller

I finally joined the HDTV club. Since I refuse to pay the cable company even more for something that comes over the air for free, I decided to resurrect the TV antenna on my roof. Works pretty good, I get about 8 digital stations pointing SE in San Jose, CA.<p>Naturally, I want to turn my antenna si...
by haklesup
Fri May 07, 2004 3:24 pm
Forum: General Discussion
Topic: IC chips by commitee.
Replies: 9
Views: 1826

Re: IC chips by commitee.

Oops, me bad. I tend to blame Bill for a lot of things that are not his fault.