ante

http://gbppr.trighost.org/lpfm/index.html “You are not authorized to view this page” None of these links works for me!? :-\

The contact points looks badly burnt, maybe they stick and course the irregular operation.

Hi MNA, I was not able to open your link; can you please check if it’s valid?

Hi cr555, Welcome to our forum! I believe this article covers any angle of the 555, I am sure you will find what you are looking for here: http://www.uoguelph.ca/~antoon/gadgets/555/555.html BDW; the link is one of many useful links on our articles page: http://www.electronics-lab.com/articles/index.html I hope this is helpful! ;)

I agree 100%!

I think this device is advanced compared to a 7812. As Muhammad says there is no need for a transformer so compared to older style powersupply modules thats pretty advanced. Well I don’t agree fully but I can see your point here! ;)

Very smartly put AG! ;D

That explains part of it! There must be a big capacitor (X1 oor X2 type maybe) and some resistor / zener diode rectifier/voltage divider close to where the mains voltage enters the unit.

Ok, ozzy strine then! Yeah, I see you’re a bloke from down under, should have known! ;D

I consider “sophisticated” to be somewhat “advanced” which I do not think this is! I also do not understand what farming terms like “agricultural” have to do with this! ???

Hi Adam, OK, I’m kind of confused here sorry! :-[ Right or wrong; the unit works of the wall if you feed it through the DC-jack and in the wallsocket without the need of external power?!?! :-\

This is the one: http://wwww.ges.cz/sheet/2/2sc5302.pdf

You see, I was almost right it has two cylinders just like I said! ;D

Hi Adam, Ok, I got confused by the info in the radioshack link you provided? Then what is the purpose of the DC jack, could it be the power the unit from a wallwart? The pictures are not clear enough (at least not for me) to see where the tracks goes.

Hi prateeksikka, These might come in handy: hxxp://rapidshare.de/files/15970792/McGraw_Hill_-_Antenna_Engineering_Handbook_-_3ed_-_Johnson.pdf.html hxxp://rapidshare.de/files/9671739/Wiley_-_Antenna_and_EM_Modeling_with_MATLAB.zip.html

Hi cynicmonster, I see no problems connecting a voltmeter to these batterys; just don’t drop your monkey-wrench on the batterys doing it! You should have the greatest respect for the current in these batterys with there low internal resistance they can produce 3000 – 5000 A easy if you short circuit them. 8)

Hi, Oh, I see! But I would not call that a “sophisticated lab Power Supply”! I would expect a lot more from such a device! :-\

The 18Volts is for the relay side of the circuit and the battery supplies the rest of it. I think the battery might supply some of the circuit and some of it is supplied from mains this can be the reason for the 24V relay! Perhaps the circuit is made this way to save on battery current, but I am not sure. I tried to follow the tracks on the pictures but it was too small (or maybe it’s my eyes)! A few things to clarify the basics: The battery; is it inside the unit or is it connected to the DC-jack? If not, what's the purpose of the DC-jack? Does the relay engage even if the unit is lying on the table or only when it’s in the mains socket? :-\

Hi, I don’t understand what you mean. Can you provide the information and circuit diagram of how to build a “sophisticated lab Power Supply” with one of these converters please? Thank you! :)

Hi Kain! Holy Cow! :o An outstanding job, you must have put quite a few hours in this one! I am sure most of our members would like to have one just like it! :D

Hi microzone, You can buy cheap vibrator-motors here: http://www.voti.nl/shop/p/motor.html ;)

Is this device run from a wallwart, not from power coming directly from the outlet? I doubt that the circuit will work properly in all stages with a 9v battery. I don’t believe they would use different voltages for the RF circuit and the relay latch circuit, it would be unnecessary complex and expensive. But you could try to use two 9v batterys in series (18v), which might work. Just don’t expect two 9V PP3s to keep the relay closed for a very long time! ;)

Hi Adam, Welcome to our forum! The “metal tab / electromagnet” as you call it is a relay. How about the black thing on the side, is it a DC jack or am I wrong? Can this be a way to power the unit, or is it used for something completely different? :)

Perhaps an R/C link between pin 4 and 5 would do it.