It is currently Thu Feb 22, 2018 2:40 am

All times are UTC - 8 hours


Search found 2642 matches
Search these results:

Author Message

 Forum: General Discussion   Topic: Telemecanique Modicon TSX Nano 07 PLC

Posted: Mon Feb 12, 2018 5:49 pm 

Replies: 3
Views: 102


without knowing the details of construction it is hard to say. you said NVR and I thought of a battery backed RAM but it might not be. A photo of the guts would help in that assessment or a list of IC part numbers. What is the vintage? Battery backed RAM would be up to mid 90s I would guess. maybe s...

 Forum: General Discussion   Topic: Telemecanique Modicon TSX Nano 07 PLC

Posted: Mon Feb 12, 2018 4:16 pm 

Replies: 3
Views: 102


an NVR has an internal backup battery but I am unsure if it can be measured external to the package (pin 16 and 20 on some). Its old technology with flash memory and EPROMS mostly replacing it. Is there a coin battery on the module, you would think they would have replaced it when they reloaded thou...

 Forum: General Discussion   Topic: Detecting a magnet... from a distance.

Posted: Sat Feb 03, 2018 9:00 pm 

Replies: 18
Views: 387


A magnetic wave travels at the speed of light, and not very far when not coupled with an electric field. I don't think any analog circuit would have the response time to measure a differential. With audio the wave travels slower and it still took DSP to make it practical. With DSP the incoming signa...

 Forum: General Discussion   Topic: Detecting a magnet... from a distance.

Posted: Thu Feb 01, 2018 1:08 pm 

Replies: 18
Views: 387


How slow, too slow and it might as well be stationary as the flux will not couple well into most detectors. a DC magnetic field can be detected with a compass and if smaller than Earth's won't wiggle a needle much. At some point the signal would drop so far into the noise it would become undetectabl...

 Forum: General Discussion   Topic: i need some more Unobtainum...

Posted: Fri Jan 26, 2018 10:47 am 

Replies: 15
Views: 293


LM317 is old school. and with 6V dropped across it, won't be very efficient. there are plenty of small module battery to 3.3V regulators that will well outperform the battery in there now. Search "3V boost regulator" or similar on ebay and you'll find plenty with various specs to choose fr...

 Forum: General Discussion   Topic: i need some more Unobtainum...

Posted: Tue Jan 23, 2018 12:17 pm 

Replies: 15
Views: 293


if your scope is fast enough, you should be able to lock onto the carrier frequency and check the frequency. Demodulating and reading out the digital data is more difficult but if you see modulation on the carrier, you can be relatively sure there is some kind of data. It is unlikely the data is jum...

 Forum: General Discussion   Topic: i need some more Unobtainum...

Posted: Mon Jan 22, 2018 5:50 pm 

Replies: 15
Views: 293


Can I assume that since the chip is an RF receiver, the display lights up but just shows an empty reading all the time? http://www.allparts.co.kr/pdffile/pdffile_001/3274.pdf How do you know the transmitter is transmitting or just lighting its power lamp? Check the crystal oscillator and the series ...

 Forum: General Discussion   Topic: Hammond die cast al case, heat sink?

Posted: Fri Jan 19, 2018 8:20 pm 

Replies: 11
Views: 314


if the polished surface still looks like round beads with voids between, I will believe it but the "Die cast" process formally uses molten metal and the molds are often very rough, maybe even sand molds or bead blasted surface. its not very different from plastic molding for a low melt tem...

 Forum: General Discussion   Topic: did I blow my Amp

 Post subject: Re: did I blow my Amp
Posted: Wed Jan 17, 2018 8:53 pm 

Replies: 6
Views: 229


Not the fuse. Initially I didn't check because the pilot lamp was turning on and off with the remote switch as expected but than I worried there might be a current path to the LED without power but although there is, the resistance is too high to light the lamp. I checked it today and was good. Mute...

 Forum: General Discussion   Topic: did I blow my Amp

 Post subject: Re: did I blow my Amp
Posted: Tue Jan 16, 2018 5:15 pm 

Replies: 6
Views: 229


I agree it is repairable, I need to take it out of the car and put together a bench setup with some signal sources first. I've had these sitting on a shelf for nearly a decade and now I am completely refurbishing my 93 Explorer and these fit well under the seats. (they were insurance replacements fo...

 Forum: General Discussion   Topic: LOREX LW2742 Wireless Monitor........

Posted: Tue Jan 16, 2018 5:01 pm 

Replies: 10
Views: 242


one can still change the front glass on a smart phone but that's just about it in 2018. On the flip side, we have never had such a large selection of prebuilt electronic modules and boards and dev kits.

 Forum: General Discussion   Topic: did I blow my Amp

 Post subject: did I blow my Amp
Posted: Mon Jan 15, 2018 3:26 pm 

Replies: 6
Views: 229


I was working with an Alpine 2 channel car amp and trying to bridge outputs to a dual voice coil subwoofer. 4 ohms x2 Initially I got some output putting each coil on Left and Right but that's not a proper hookup. next step I paralleled the VC to obtain 2 ohms impedance and placed it across (what I ...

 Forum: General Discussion   Topic: Hammond die cast al case, heat sink?

Posted: Mon Jan 15, 2018 11:53 am 

Replies: 11
Views: 314


The difference in surface appearance is probably from the casting process which takes up imperfections and texture of the mold surface. if you are comparing to extruded aluminum or machined aluminum then that surface will be smoother and brighter and have less dark oxides from cooling. Sand with 220...

 Forum: General Discussion   Topic: LOREX LW2742 Wireless Monitor........

Posted: Thu Jan 11, 2018 1:46 pm 

Replies: 10
Views: 242


Engineered to mess specifically with you. Seems like you offered the best option. Another would be to replace the power supply with one with a cord you could match with the socket or splice a new connector, not as neat as you would like I suppose.

 Forum: General Discussion   Topic: Laptop charger voltage...

Posted: Fri Jan 05, 2018 1:46 pm 

Replies: 1
Views: 141


I think you probably could charge direct from a car but since that source is not regulated, it might e a bit hard on the battery or charging circuits. Not running, my car battery hovers at 11.4 (its a little old) and when running is 14.5. With the car running it might work OK but with the car off, y...
Sort by:  
Page 1 of 177 [ Search found 2642 matches ]


All times are UTC - 8 hours


Jump to:  

cron