ante

Sorry to see you leave Yevgeni! Too bad, no book and no moderator for the “Theory articles” column! :'(

Hi Steven, It looks like the coil from a two cylinder motorcycle!

Yes, that’s exactly right and contactors, some relays, electro magnets, solenoid valves, solenoids that move things inside a VCR,s and many other kinds of equipment etc.

Any coil is an inductor but in the case of a solenoid there could be a difference if the solenoid has a moving core (anchor) inside. When the core moves the inductance value changes.

Hi MP, That’s a simple circuit for the job, but will the BC108 saturate with clean water? Maybe it does, it could be worth a try.

Hi alkv, You could try Kool-Pak resistors instead; just bolt them to the chassis to keep them cool! http://www.elfa.se/pdf/60/06059984.pdf The 100W version is very hard to kill! ;)

Great Logan, you found it! ;D

Happy Birthday Steven! Take it easy and you’ll be fine! ;D

OK, here it is!

Maybe he’s a bartender, but then again ‘water’…. naa maybe not! ;D

Oh the Philippines, that’s nice! 8) Well, I don’t know if op-amps are the best choice for your plastic rod; maybe this is better for several reasons: http://www.uoguelph.ca/~antoon/circ/sensor3.htm This circuit duplicated, one for each level you want to detect and just keep the relay for the once which needs alarm. For the rest of the levels use an LED of suitable color. Let me know what you think ! ;)

Hi microzone, Is it a must to use a belt? A conveyor transfer system can be built in different ways. Is it suppose to run in one direction only or do you like it to be reversible? Can you give some more details please?

Hi Bob, It looks like a very peaceful place you live in, nice climate too. I know you have more or less decided which way to go but one thing came to my mind; how about an ultrasonic ruler aimed at the water surface, it would give you the exact level? I think it might be possible to tap into such a “ruler” to get an alarm level too.

Hi jackrs, Wellcome to this forum! Yes, the complete manual coming up right away! ;D Manual_K7200.pdf

Haven’t seen much of him for some time, think he’s busy with studies!

Hi Guys, There are a few ways to achieve the multi winding changeover trick. These techniques greatly reduce the heat dissipation in any linear PSU. I attach two examples of how it can be done, one circuit for a split winding and another one using a four pole winding.

Hi Logan, It was posted here but it got lost somehow! ???

Hi alkv, What kind of problems do you have with the resistor?

Hi Guys, A hardware crash…. is that when the computer fall of your desk and onto the floor? ;D Sorry Staigen, just kidding! I hope you can fix it soon! ;)

That’s probably true but still the values for the parts will help to find out exactly what this circuit does! ;)

Hi, Most laptops I have encountered will work fine without its battery pack present. If you need your computer and have access to mains power you should be able to run it if you remove the battery. However, I’m not sure if it’s possible to discharge the battery outside the computer and make it start afterwards because in some computers the battery measuring circuit might be in the computer not in the battery. If the circuit is inside the pack you can discharge it with a resistor or a small bulb (12V 5W) but not unattended since a completely flat battery might give you further problems. I hope this helps.

That circuit will not supply a constant current!

Good Luck. Yeah, pictures would be nice! ;D

Oh, I assumed there was a walk-a-round inspection path for the tank. Is it completely buryed or is its top above ground level? A mechanical device would be the safe way to do it.

Yes, that would be very interesting. And a similar device for laser guns is even more useful! ;)